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author | priyanka | 2015-06-24 15:03:17 +0530 |
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committer | priyanka | 2015-06-24 15:03:17 +0530 |
commit | b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b (patch) | |
tree | ab291cffc65280e58ac82470ba63fbcca7805165 /2705 | |
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initial commit / add all books
Diffstat (limited to '2705')
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diff --git a/2705/CH1/EX1.1/Ex1_1.sce b/2705/CH1/EX1.1/Ex1_1.sce new file mode 100755 index 000000000..e41b309e6 --- /dev/null +++ b/2705/CH1/EX1.1/Ex1_1.sce @@ -0,0 +1,17 @@ +clear ; +clc; +disp('Example 1.1'); + + + +// Given values +P = 700; //pressure,[kN/m^2] +V1 = .28; //initial volume,[m^3] +V2 = 1.68; //final volume,[m^3] + +//solution + +W = P*(V2-V1);// // Formula for work done at constant pressure is, [kJ] +mprintf('\n The Work done is = %f MJ\n',W*10^-3); + +//End diff --git a/2705/CH1/EX1.10/Ex1_10.sce b/2705/CH1/EX1.10/Ex1_10.sce new file mode 100755 index 000000000..801ac3a6f --- /dev/null +++ b/2705/CH1/EX1.10/Ex1_10.sce @@ -0,0 +1,21 @@ +clear; +clc; +disp('Example 1.10'); + + + +// Given values +m_dot = 3.045; // use of coal, [tonne/h] +c = 28; // calorific value of the coal, [MJ/kg] +P_out = 4.1; // output of turbine, [MW] + +// solution +m_dot = m_dot*10^3/3600; // [kg/s] + +P_in = m_dot*c; // power input by coal, [MW] + +n = P_out/P_in; // thermal efficiency formula + +mprintf('\n Thermal efficiency of the plant is = %f \n',n); + +//End diff --git a/2705/CH1/EX1.11/Ex1_11.sce b/2705/CH1/EX1.11/Ex1_11.sce new file mode 100755 index 000000000..de23f795c --- /dev/null +++ b/2705/CH1/EX1.11/Ex1_11.sce @@ -0,0 +1,17 @@ +clear; +clc; +disp('Example 1.11'); + + +// Given values +v = 50; // speed, [km/h] +F = 900; // Resistance to the motion of a car + +// solution +v = v*10^3/3600; // [m/s] + Power = F*v; // Power formula, [W] + +mprintf('\n The power output of the engine is = %f kW\n',Power*10^-3); + + // End + diff --git a/2705/CH1/EX1.12/Ex1_12.sce b/2705/CH1/EX1.12/Ex1_12.sce new file mode 100755 index 000000000..426f6c26d --- /dev/null +++ b/2705/CH1/EX1.12/Ex1_12.sce @@ -0,0 +1,25 @@ + +clear; +clc; +disp('Example 1.12'); + + + +// Given values +V = 230; // volatage, [volts] +I = 60; // current, [amps] +n_gen = .95; // efficiency of generator +n_eng = .92; // efficiency of engine + +// solution + +P_gen = V*I; // Power delivered by generator, [W] +P_gen=P_gen*10^-3; // [kW] + +P_in_eng=P_gen/n_gen;//Power input from engine,[kW] + +P_out_eng=P_in_eng/n_eng;//Power output from engine,[kW] + +mprintf('\n The power output from the engine is = %f kW\n',P_out_eng); + +// End diff --git a/2705/CH1/EX1.13/Ex1_13.sce b/2705/CH1/EX1.13/Ex1_13.sce new file mode 100755 index 000000000..c91fa71a0 --- /dev/null +++ b/2705/CH1/EX1.13/Ex1_13.sce @@ -0,0 +1,17 @@ +clear; +clc; +disp('Example 1.13'); + + + +// Given values +V = 230; // Voltage, [volts] +W = 4; // Power of heater, [kW] + +// solution + +// using equation P=VI +I = W/V; // current, [K amps] +mprintf('\n The current taken by heater is = %f amps \n',I*10^3); + +// End diff --git a/2705/CH1/EX1.14/Ex1_14.sce b/2705/CH1/EX1.14/Ex1_14.sce new file mode 100755 index 000000000..857faf8fc --- /dev/null +++ b/2705/CH1/EX1.14/Ex1_14.sce @@ -0,0 +1,24 @@ +clear; +clc; +disp('Example 1.14'); + + + +// Given values +P_out = 500; // output of power station, [MW] +c = 29.5; // calorific value of coal, [MJ/kg] +r=.28; + +// solution + +// since P represents only 28 percent of energy available from coal +P_coal = P_out/r; // [MW] + +m_coal = P_coal/c; // Mass of coal used, [kg/s] +m_coal = m_coal*3600; // [kg/h] + +//After one hour +m_coal = m_coal*1*10^-3; // [tonne] +mprintf('\n Mass of coal burnt by the power station in 1 hour is = %f tonne \n',m_coal); + +// End diff --git a/2705/CH1/EX1.2/Ex1_2.sce b/2705/CH1/EX1.2/Ex1_2.sce new file mode 100755 index 000000000..dab25d43a --- /dev/null +++ b/2705/CH1/EX1.2/Ex1_2.sce @@ -0,0 +1,21 @@ +clear; +clc; +disp('Example 1.2'); + + + +//Given values +P1 = 138; // initial pressure,[kN/m^2] +V1 = .112; //initial volume,[m^3] +P2 = 690; // final pressure,[kN/m^2] +Gama=1.4; // heat capacity ratio + +// solution + +// since gas is following, PV^1.4=constant,hence + +V2 =V1*(P1/P2)^(1/Gama); // final volume, [m^3] + +mprintf('\n The new volume of the gas is = %f m^3\n',V2) + +//End diff --git a/2705/CH1/EX1.3/Ex1_3.sce b/2705/CH1/EX1.3/Ex1_3.sce new file mode 100755 index 000000000..bddd96cd3 --- /dev/null +++ b/2705/CH1/EX1.3/Ex1_3.sce @@ -0,0 +1,26 @@ +clear; +clc; +disp('Example 1.3'); + + + +// Given values +P1 = 2070; // initial pressure, [kN/m^2] +V1 = .014; // initial volume, [m^3] +P2 = 207; // final pressure, [kN/m^2] +n=1.35; // polytropic index + +// solution + +// since gas is following PV^n=constant +// hence + +V2 = V1*(P1/P2)^(1/n); // final volume, [m^3] + +// calculation of workdone + +W=(P1*V1-P2*V2)/(1.35-1); // using work done formula for polytropic process, [kJ] + +mprintf('\n The Work done by gas during expansion is = %f kJ\n',W); + +//End diff --git a/2705/CH1/EX1.4/Ex1_4.sce b/2705/CH1/EX1.4/Ex1_4.sce new file mode 100755 index 000000000..6ae65d27c --- /dev/null +++ b/2705/CH1/EX1.4/Ex1_4.sce @@ -0,0 +1,26 @@ +clear; +clc; +disp('Example 1.4'); + + + +// Given values +P1 = 100; // initial pressure, [kN/m^2] +V1 = .056; // initial volume, [m^3] +V2 = .007; // final volume, [m^3] + +// To know P2 +// since process is hyperbolic so, PV=constant +// hence + +P2 = P1*V1/V2; // final pressure, [kN/m^2] + +mprintf('\n The final pressure is = %f kN/m^2\n',P2); + +// calculation of workdone + +W = P1*V1*log(V2/V1); // formula for work done in this process, [kJ] + +mprintf('\n Work done on the gas is = %f kJ\n',W); + +//End diff --git a/2705/CH1/EX1.5/Ex1_5.sce b/2705/CH1/EX1.5/Ex1_5.sce new file mode 100755 index 000000000..2e651d7e1 --- /dev/null +++ b/2705/CH1/EX1.5/Ex1_5.sce @@ -0,0 +1,19 @@ +clear; +clc; +disp('Example 1.5'); + + + +// Given values +m = 5; // mass, [kg] +t1 = 15; // inital temperature, [C] +t2 = 100; // final temperature, [C] +c = 450; // specific heat capacity, [J/kg K] + +// solution + +// using heat transfer equation,[1] +Q = m*c*(t2-t1); // [J] +mprintf('\n The heat required is = %f kJ\n',Q*10^-3); + +//End diff --git a/2705/CH1/EX1.6/Ex1_6.sce b/2705/CH1/EX1.6/Ex1_6.sce new file mode 100755 index 000000000..fe3ceb552 --- /dev/null +++ b/2705/CH1/EX1.6/Ex1_6.sce @@ -0,0 +1,28 @@ +clear; +clc; +disp('Example 1.6'); + + +// Given values +m_cop = 2; // mass of copper vessel, [kg] +m_wat = 6; // mass of water, [kg] +c_wat = 4.19; // specific heat capacity of water, [kJ/kg K] + +t1 = 20; // initial temperature, [C] +t2 = 90; // final temperature, [C] + +// From the table of average specific heat capacities +c_cop = .390; // specific heat capacity of copper,[kJ/kg k] + +// solution +Q_cop = m_cop*c_cop*(t2-t1); // heat required by copper vessel, [kJ] + +Q_wat = m_wat*c_wat*(t2-t1); // heat required by water, [kJ] + +// since there is no heat loss,so total heat transfer is sum of both +Q_total = Q_cop+Q_wat ; // [kJ] + +mprintf(' \n Required heat transfer to accomplish the change = %f kJ\n',Q_total); + +//End + diff --git a/2705/CH1/EX1.7/Ex1_7.sce b/2705/CH1/EX1.7/Ex1_7.sce new file mode 100755 index 000000000..5fb3d347d --- /dev/null +++ b/2705/CH1/EX1.7/Ex1_7.sce @@ -0,0 +1,23 @@ + +clear; +clc; +disp('Example 1.7'); + + +// Given values +m = 10; // mass of iron casting, [kg] +t1 = 200; // initial temperature, [C] +Q = -715.5; // [kJ], since heat is lost in this process + +// From the table of average specific heat capacities +c = .50; // specific heat capacity of casting iron, [kJ/kg K] + +// solution +// using heat equation +// Q = m*c*(t2-t1) + +t2 = t1+Q/(m*c); // [C] + +mprintf('\n The final temperature is t2 = %f C\n',t2); + +// End diff --git a/2705/CH1/EX1.8/Ex1_8.sce b/2705/CH1/EX1.8/Ex1_8.sce new file mode 100755 index 000000000..6febbea57 --- /dev/null +++ b/2705/CH1/EX1.8/Ex1_8.sce @@ -0,0 +1,22 @@ +clear; +clc; +disp('Example 1.8'); + + + +// Given values +m = 4; // mass of the liquid, [kg] +t1 = 15; // initial temperature, [C] +t2 = 100; // final temperature, [C] +Q = 714; // [kJ],required heat to accomplish this change + +// solution +// using heat equation +// Q=m*c*(t2-t1) + +// calculation of c +c=Q/(m*(t2-t1)); // heat capacity, [kJ/kg K] + +mprintf('\n The specific heat capacity of the liquid is c = %f kJ/kg K\n',c); + +//End diff --git a/2705/CH1/EX1.9/Ex1_9.sce b/2705/CH1/EX1.9/Ex1_9.sce new file mode 100755 index 000000000..a5cc15bad --- /dev/null +++ b/2705/CH1/EX1.9/Ex1_9.sce @@ -0,0 +1,27 @@ +clear; +clc; +disp('Example 1.9'); + + +// Given values +m_dot = 20.4; // mass flowrate of petrol, [kg/h] +c = 43; // calorific value of petrol, [MJ/kg] +n = .2; // Thermal efficiency of engine + +// solution +m_dot = 20.4/3600; // [kg/s] +c = 43*10^6; // [J/kg] + +// power output +P_out = n*m_dot*c; // [W] + +mprintf('\n The power output of the engine is = %f kJ\n',P_out*10^-3); + +// power rejected + +P_rej = m_dot*c*(1-n); // [W] +P_rej = P_rej*60*10^-6; // [MJ/min] + +mprintf('\n The energy rejected by the engine is = %f MJ/min \n',P_rej); + +//End diff --git a/2705/CH10/EX10.1/Ex10_1.sce b/2705/CH10/EX10.1/Ex10_1.sce new file mode 100755 index 000000000..563d4d450 --- /dev/null +++ b/2705/CH10/EX10.1/Ex10_1.sce @@ -0,0 +1,31 @@ +clear;
+clc;
+disp('Example 10.1');
+
+// aim : To determine
+// the equivalent evaporation
+
+// Given
+P = 1.4;// [MN/m^2]
+m = 8;// mass of water,[kg]
+T1 = 39;// entering temperature,[C]
+T2 = 100;// [C]
+x = .95;//dryness fraction
+
+// solution
+hf = 830.1;// [kJ/kg]
+hfg = 1957.7;// [kJ/kg]
+// steam is wet so specific enthalpy of steam is
+h = hf+x*hfg;// [kJ/kg]
+
+// at 39 C
+h1 = 163.4;// [kJ/kg]
+// hence
+q = h-h1;// [kJ/kg]
+Q = m*q;// [kJ]
+
+evap = Q/2256.9;// equivalent evaporation[kg steam/(kg coal)]
+
+mprintf('\n The equivalent evaporation, from and at 100 C is = %f kg steam/kg coal\n ',evap);
+
+// End
diff --git a/2705/CH10/EX10.10/Ex10_10.sce b/2705/CH10/EX10.10/Ex10_10.sce new file mode 100755 index 000000000..c0d346f7f --- /dev/null +++ b/2705/CH10/EX10.10/Ex10_10.sce @@ -0,0 +1,64 @@ +clear;
+clc;
+disp('Example 10.10');
+
+// aim : To determine
+// (a) the mass of steam bled to each feed heater in kg/kg of supply steam
+// (b) the thermal efficiency of the arrangement
+
+// given values
+P1 = 7;// steam initial pressure, [MN/m^2]
+T1 = 273+500;// steam initil temperature, [K]
+P2 = 2;// pressure at stage 1, [MN/m^2]
+P3 = .5;// pressure at stage 2, [MN/m^2]
+P4 = .05;// condenser pressure,[MN/m^2]
+SE = .82;// stage efficiency of turbine
+
+// solution
+// from the enthalpy-entropy chart(Fig10.23) values of specific enthalpies are
+h1 = 3410;// [kJ/kg]
+h2_prim = 3045;// [kJ/kg]
+// h1-h2=SE*(h1-h2_prim), so
+h2 = h1-SE*(h1-h2_prim);// [kJ/kg]
+
+h3_prim = 2790;// [kJ/kg]
+// h2-h3=SE*(h2-h3_prim), so
+h3 = h2-SE*(h2-h3_prim);// [kJ/kg]
+
+h4_prim = 2450;// [kJ/kg]
+// h3-h4 = SE*(h3-h4_prim), so
+h4 = h3-SE*(h3-h4_prim);// [kJ/kg]
+
+// from steam table
+// @ 2 MN/m^2
+hf2 = 908.6;// [kJ/kg]
+// @ .5 MN/m^2
+hf3 = 640.1;// [kJ/kg]
+// @ .05 MN/m^2
+hf4 = 340.6;// [kJ/kg]
+
+// (a)
+// for feed heater1
+m1 = (hf2-hf3)/(h2-hf3);// mass of bled steam, [kg/kg supplied steam]
+// for feed heater2
+m2 = (1-m1)*(hf3-hf4)/(h3-hf4);//
+mprintf('\n (a) The mass of steam bled in feed heater 1 is = %f kg/kg supply steam\n',m1);
+mprintf('\n The mass of steam bled in feed heater 2 is = %f kg/kg supply steam\n',m2);
+
+// (b)
+W = (h1-h2)+(1-m1)*(h2-h3)+(1-m1-m2)*(h3-h4);// theoretical work done, [kJ/kg]
+Eb = h1-hf2;// energy input in the boiler, [kJ/kg]
+TE1 = W/Eb;// thermal efficiency
+mprintf('\n (b) The thermal efficiency of the arrangement is = %f percent\n',TE1*100);
+
+// If there is no feed heating
+hf5 = hf4;
+h5_prim = 2370;// [kJ/kg]
+// h1-h5 = SE*(h1-h5_prim), so
+h5 = h1-SE*(h1-h5_prim);// [kJ/kg]
+Ei = h1-hf5;//energy input, [kJ/kg]
+W = h1-h5;// theoretical work, [kJ/kg]
+TE2 = W/Ei;// thermal efficiency
+mprintf('\n The thermal efficiency if there is no feed heating is = %f percent\n',TE2*100);
+
+// End
diff --git a/2705/CH10/EX10.2/Ex10_2.sce b/2705/CH10/EX10.2/Ex10_2.sce new file mode 100755 index 000000000..7993e77ac --- /dev/null +++ b/2705/CH10/EX10.2/Ex10_2.sce @@ -0,0 +1,47 @@ +clear;
+clc;
+disp('Example 10.2');
+
+// aim : To determine
+// the mass of oil used per hour and the fraction of enthalpy drop through the turbine
+// heat transfer available per kilogram of exhaust steam
+
+// Given values
+ms_dot = 5000;// generation of steam, [kg/h]
+P1 = 1.8;// generated steam pressure, [MN/m^2]
+T1 = 273+325;// generated steam temperature, [K]
+Tf = 273+49.4;// feed temperature, [K]
+neta = .8;// efficiency of boiler plant
+c = 45500;// calorific value, [kJ/kg]
+P = 500;// turbine generated power, [kW]
+Pt = .18;// turbine exhaust pressure, [MN/m^2]
+x = .98;// dryness farction of steam
+
+// solution
+// using steam table at 1.8 MN/m^2
+hf1 = 3106;// [kJ/kg]
+hg1 = 3080;// [kJ/kg]
+// so
+h1 = hf1-neta*(hf1-hg1);// [kJ/kg]
+// again using steam table specific enthalpy of feed water is
+hwf = 206.9;// [kJ/kg]
+h_rais = ms_dot*(h1-hwf);// energy to raise steam, [kJ]
+
+h_fue = h_rais/neta;// energy from fuel per hour, [kJ]
+m_oil = h_fue/c;// mass of fuel per hour, [kg]
+
+// from steam table at exhaust
+hf = 490.7;// [kJ/kg]
+hfg = 2210.8;// [kJ/kg]
+// hence
+h = hf+x*hfg;// [kJ/kg]
+// now
+h_drop = (h1-h)*ms_dot/3600;// specific enthalpy drop in turbine [kJ]
+f = P/h_drop;// fraction ofenthalpy drop converted into work
+// heat transfer available in exhaust is
+Q = h-hwf;// [kJ/kg]
+mprintf('\n The mass of oil used per hour is = %f kg\n',m_oil);
+mprintf('\n The fraction of the enthalpy drop through the turbine that is converted into useful work is = %f\n',f);
+mprintf('\n The heat transfer available in exhaust steam above 49.4 C is = %f kJ/kg\n',Q);
+
+// End
diff --git a/2705/CH10/EX10.3/Ex10_3.sce b/2705/CH10/EX10.3/Ex10_3.sce new file mode 100755 index 000000000..5ea7c08db --- /dev/null +++ b/2705/CH10/EX10.3/Ex10_3.sce @@ -0,0 +1,44 @@ +clear;
+clc;
+disp('Example 10.3');
+
+// aim : To determine
+// (a) the thermal efficiency of the boiler
+// (b) the equivalent evaporation of the boiler
+// (c) the new coal consumption
+
+// given values
+ms_dot = 5400;// steam feed rate, [kg/h]
+P = 750;// steam pressure, [kN/m^2]
+x = .98;// steam dryness fraction
+Tf1 = 41.5;// feed water temperature, [C]
+CV = 31000;// calorific value of coal used in the boiler, [kJ/kg]
+mc1 = 670;// rate of burning of coal/h, [kg]
+Tf2 = 100;// increased water temperature, [C]
+
+// solution
+// (a)
+SRC = ms_dot/mc1;// steam raised/kg coal, [kg]
+hf = 709.3;// [kJ/kg]
+hfg = 2055.5;// [kJ/kg]
+h1 = hf+x*hfg;// specific enthalpy of steam raised, [kJ/kg]
+// from steam table
+hfw = 173.9;// specific enthalpy of feed water, [kJ/kg]
+EOB = SRC*(h1-hfw)/CV;// efficiency of boiler
+mprintf('\n (a) The thermal efficiency of the boiler is = %f percent\n',EOB*100);
+
+// (b)
+he = 2256.9;// specific enthalpy of evaporation, [kJ/kg]
+Ee = SRC*(h1-hfw)/he;// equivalent evaporation[kg/kg coal]
+mprintf('\n (b) The equivalent evaporation of boiler is = %f kg/kg coal\n',Ee);
+
+// (c)
+hw = 419.1;// specific enthalpy of feed water at 100 C, [kJ/kg]
+Eos = ms_dot*(h1-hw);// energy of steam under new condition, [kJ/h]
+neb = EOB+.05;// given condition new efficiency of boiler if 5%more than previous
+Ec = Eos/neb;// energy from coal, [kJ/h]
+mc2 = Ec/CV;// mass of coal used per hour in new condition, [kg]
+mprintf('\n (c) Mass of coal used in new condition is = %f kg\n',mc2);
+mprintf('\n The saving in coal per hour is = %f kg\n',mc1-mc2);
+
+// End
diff --git a/2705/CH10/EX10.4/Ex10_4.sce b/2705/CH10/EX10.4/Ex10_4.sce new file mode 100755 index 000000000..c7d9ea745 --- /dev/null +++ b/2705/CH10/EX10.4/Ex10_4.sce @@ -0,0 +1,46 @@ +clear;
+clc;
+disp('Example 10.4');
+
+// aim : To determine the
+// (a) Heat transfer in the boiler
+// (b) Heat transfer in the superheater
+// (c) Gas used
+
+// given values
+P = 100;// boiler operating pressure, [bar]
+Tf = 256;// feed water temperature, [C]
+x = .9;// steam dryness fraction.
+Th = 450;// superheater exit temperature, [C]
+m = 1200;// steam generation/h, [tonne]
+TE = .92;// thermal efficiency
+CV = 38;// calorific value of fuel, [MJ/m^3]
+
+// solution
+// (a)
+// from steam table
+hw = 1115.4;// specific enthalpy of feed water, [kJ/kg]
+// for wet steam
+hf = 1408;// specific enthalpy, [kJ/kg]
+hg = 2727.7;// specific enthalpy, [kJ/kg]
+// so
+h = hf+x*(hg-hf);// total specific enthalpy of wet steam, [kJ/kg]
+// hence
+Qb = m*(h-hw);// heat transfer/h for wet steam, [MJ]
+mprintf('\n (a) The heat transfer/h in producing wet steam in the boiler is = %f MJ\n',Qb);
+
+// (b)
+// again from steam table
+// specific enthalpy of superheated stem at given condition is,
+hs = 3244;// [kJ/kg]
+
+Qs = m*(hs-h);// heat transfer/h in superheater, [MJ]
+mprintf('\n (b) The heat transfer/h in superheater is = %f MJ\n',Qs);
+
+// (c)
+V = (Qb+Qs)/(TE*CV);// volume of gs used/h, [m^3]
+mprintf('\n (c) The volume of gas used/h is = %f m^3\n',V);
+
+// There is calculation mistake in the book so our answer is not matching
+
+// End
diff --git a/2705/CH10/EX10.5/Ex10_5.sce b/2705/CH10/EX10.5/Ex10_5.sce new file mode 100755 index 000000000..e7086049a --- /dev/null +++ b/2705/CH10/EX10.5/Ex10_5.sce @@ -0,0 +1,31 @@ +clear;
+clc;
+disp('Example 10.5');
+
+//aim : To determine
+// the flow rate of cooling water
+
+//Given values
+P=24;//pressure, [kN/m^2]
+ms_dot=1.8;//steam condense rate,[tonne/h]
+x=.98;//dryness fraction
+T1=21;//entrance temperature of cooling water,[C]
+T2=57;//outlet temperature of cooling water,[C]
+
+//solution
+//at 24 kN/m^2, for steam
+hfg=2616.8;//[kJ/kg]
+hf1=268.2;//[kJ/kg]
+//hence
+h1=hf1+x*(hfg-hf1);//[kJ/kg]
+
+//for cooling water
+hf3=238.6;//[kJ/kg]
+hf2=88.1;//[kJ/kg]
+
+//using equation [3]
+//ms_dot*(hf3-hf2)=mw_dot*(h1-hf1),so
+mw_dot=ms_dot*(h1-hf1)/(hf3-hf2);//[tonne/h]
+disp('tonne/h',mw_dot,'The flow rate of the cooling water is =')
+
+//End
diff --git a/2705/CH10/EX10.6/Ex10_6.sce b/2705/CH10/EX10.6/Ex10_6.sce new file mode 100755 index 000000000..b4d0e04fe --- /dev/null +++ b/2705/CH10/EX10.6/Ex10_6.sce @@ -0,0 +1,49 @@ +clear;
+clc;
+disp('Example 10.6');
+
+// aim : To determine
+// (a) the energy supplied in the boiler
+// (b) the dryness fraction of the steam entering the condenser
+// (c) the rankine efficiency
+
+// given values
+P1 = 3.5;// steam entering pressure, [MN/m^2]
+T1 = 273+350;// entering temperature, [K]
+P2 = 10;//steam exhaust pressure, [kN/m^2]
+
+// solution
+// (a)
+// from steam table, at P1 is,
+hf1 = 3139;// [kJ/kg]
+hg1 = 3095;// [kJ/kg]
+h1 = hf1-1.5/2*(hf1-hg1);
+// at Point 3
+h3 = 191.8;// [kJ/kg]
+Es = h1-h3;// energy supplied, [kJ/kg]
+mprintf('\n (a) The energy supplied in boiler/kg steam is = %f kJ/kg\n',Es);
+
+// (b)
+// at P1
+sf1 = 6.960;// [kJ/kg K]
+sg1 = 6.587;// [kJ/kg K]
+s1 = sf1-1.5/2*(sf1-sg1);// [kJ/kg K]
+// at P2
+sf2 = .649;// [kJ/kg K]
+ sg2 = 8.151;// [kJ/kg K]
+ // s2=sf2+x2(sg2-sf2)
+ // theoretically expansion through turbine is isentropic so s1=s2
+ // hence
+ s2 = s1;
+ x2 = (s2-sf2)/(sg2-sf2);// dryness fraction
+ mprintf('\n (b) The dryness fraction of steam entering the condenser is = %f \n',x2);
+
+ // (c)
+ // at point 2
+ hf2 = 191.8;// [kJ/kg]
+ hfg2 = 2392.9;// [kJ/kg]
+ h2 = hf2+x2*hfg2;// [kJ/kg]
+ Re = (h1-h2)/(h1-h3);// rankine efficiency
+ mprintf('\n (c) The Rankine efficiency is = %f percent\n',Re*100);
+
+ // End
diff --git a/2705/CH10/EX10.7/Ex10_7.sce b/2705/CH10/EX10.7/Ex10_7.sce new file mode 100755 index 000000000..b3e5be740 --- /dev/null +++ b/2705/CH10/EX10.7/Ex10_7.sce @@ -0,0 +1,61 @@ +clear;
+clc;
+disp('Example 10.7');
+
+// aim : To determine
+// the specific work done and compare this with that obtained when determining the rankine effficiency
+
+// given values
+P1 = 1000;// steam entering pressure, [kN/m^2]
+x1 = .97;// steam entering dryness fraction
+P2 = 15;//steam exhaust pressure, [kN/m^2]
+n = 1.135;// polytropic index
+
+// solution
+// (a)
+// from steam table, at P1 is
+hf1 = 762.6;// [kJ/kg]
+hfg1 = 2013.6;// [kJ/kg]
+h1 = hf1+hfg1; // [kJ/kg]
+
+sf1 = 2.138;// [kJ/kg K]
+sg1 = 6.583;// [kJ/kg K]
+s1 = sf1+x1*(sg1-sf1);// [kJ/kg K]
+
+// at P2
+sf2 = .755;// [kJ/kg K]
+ sg2 = 8.009;// [kJ/kg K]
+// s2 = sf2+x2(sg2-sf2)
+// since expansion through turbine is isentropic so s1=s2
+ // hence
+ s2 = s1;
+ x2 = (s2-sf2)/(sg2-sf2);// dryness fraction
+
+ // at point 2
+ hf2 = 226.0;// [kJ/kg]
+ hfg2 = 2373.2;// [kJ/kg]
+ h2 = hf2+x2*hfg2;// [kJ/kg]
+
+// at Point 3
+h3 = 226.0;// [kJ/kg]
+
+// (a)
+ Re = (h1-h2)/(h1-h3);// rankine efficiency
+ mprintf('\n (a) The Rankine efficiency is = %f percent\n',Re*100);
+
+// (b)
+vg1 = .1943;// specific volume at P1, [m^3/kg]
+vg2 = 10.02;// specific volume at P2, [m^3/kg]
+V1 = x1*vg1;// [m^3/kg]
+V2 = x2*vg2;// [m^3/kg]
+
+W1 = n/(n-1)*(P1*V1-P2*V2);// specific work done, [kJ/kg]
+
+// from rankine cycle
+W2 = h1-h2;// [kJ/kg]
+mprintf('\n (b) The specific work done is = %f kJ/kg\n',W1);
+mprintf('\n The specific work done (from rankine) is = %f kJ/kg\n',W2);
+
+// there is calculation mistake in the book so our answer is not matching
+
+// End
diff --git a/2705/CH10/EX10.8/Ex10_8.sce b/2705/CH10/EX10.8/Ex10_8.sce new file mode 100755 index 000000000..f65703173 --- /dev/null +++ b/2705/CH10/EX10.8/Ex10_8.sce @@ -0,0 +1,63 @@ +clear;
+clc;
+disp('Example 10.8');
+
+// aim : To determine
+// (a) the rankine fficiency
+// (b) the specific steam consumption
+// (c) the carnot efficiency of the cycle
+
+// given values
+P1 = 1100;// steam entering pressure, [kN/m^2]
+T1 = 273+250;// steam entering temperature, [K]
+P2 = 280;// pressure at point 2, [kN/m^2]
+P3 = 35;// pressure at point 3, [kN/m^2]
+
+// solution
+// (a)
+// from steam table, at P1 and T1 is
+hf1 = 2943;// [kJ/kg]
+hg1 = 2902;// [kJ/kg]
+h1 = hf1-.1*(hf1-hg1); // [kJ/kg]
+
+sf1 = 6.926;// [kJ/kg K]
+sg1 = 6.545;// [kJ/kg K]
+s1 = sf1-.1*(sf1-sg1);// [kJ/kg K]
+
+// at P2
+sf2 = 1.647;// [kJ/kg K]
+ sg2 = 7.014;// [kJ/kg K]
+// s2=sf2+x2(sg2-sf2)
+// since expansion through turbine is isentropic so s1=s2
+ // hence
+ s2 = s1;
+ x2 = (s2-sf2)/(sg2-sf2);// dryness fraction
+
+ // at point 2
+ hf2 = 551.4;// [kJ/kg]
+ hfg2 = 2170.1;// [kJ/kg]
+ h2 = hf2+x2*hfg2;// [kJ/kg]
+ vg2 = .646;// [m^3/kg]
+ v2 = x2*vg2;// [m^3/kg]
+
+ // by Fig10.20.
+ A6125 = h1-h2;// area of 6125, [kJ/kg]
+ A5234 = v2*(P2-P3);// area 5234, [kJ/kg]
+ W = A6125+A5234;// work done
+ hf = 304.3;// specific enthalpy of water at condenser pressuer, [kJ/kg]
+ ER = h1-hf;// energy received, [kJ/kg]
+ Re = W/ER;// rankine efficiency
+ mprintf('\n (a) The rankine efficiency is = %f percent\n',Re*100);
+
+ // (b)
+ kWh = 3600;// [kJ]
+ SSC = kWh/W;// specific steam consumption, [kJ/kWh]
+ mprintf('\n (b) The specific steam consumption is = %f kJ/kWh\n',SSC);
+
+ // (c)
+ // from steam table
+T3 = 273+72.7;// temperature at point 3
+CE = (T1-T3)/T1;// carnot efficiency
+mprintf('\n (c) The carnot efficiency of the cycle is = %f percent\n',CE*100);
+
+// End
diff --git a/2705/CH10/EX10.9/Ex10_9.sce b/2705/CH10/EX10.9/Ex10_9.sce new file mode 100755 index 000000000..cd4a60ca0 --- /dev/null +++ b/2705/CH10/EX10.9/Ex10_9.sce @@ -0,0 +1,48 @@ +clear;
+clc;
+disp('Example 10.9');
+
+// aim : To determine
+// (a) the theoretical power of steam passing through the turbine
+// (b) the thermal efficiency of the cycle
+// (c) the thermal efficiency of the cycle assuming there is no reheat
+
+// given values
+P1 = 6;// initial pressure, [MN/m^2]
+T1 = 450;// initial temperature, [C]
+P2 = 1;// pressure at stage 1, [MN/m^2]
+P3 = 1;// pressure at stage 2, [MN/m^2]
+T3 = 370;// temperature, [C]
+P4 = .02;// pressure at stage 3, [MN/m^2]
+P5 = .02;// pressure at stage 4, [MN/m^2]
+T5 = 320;// temperature, [C]
+P6 = .02;// pressure at stage 5, [MN/m^2]
+P7 = .02;// final pressure , [MN/m^2]
+
+// solution
+// (a)
+// using Fig 10.21
+h1 = 3305;// specific enthalpy, [kJ/kg]
+h2 = 2850;// specific enthalpy, [kJ/kg]
+h3 = 3202;// specific enthalpy, [kJ/kg]
+h4 = 2810;// specific enthalpy, [kJ/kg]
+h5 = 3115;// specific enthalpy, [kJ/kg]
+h6 = 2630;// specific enthalpy, [kJ/kg]
+h7 = 2215;// specific enthalpy, [kJ/kg]
+W = (h1-h2)+(h3-h4)+(h5-h6);// specific work through the turbine, [kJ/kg]
+mprintf('\n (a) The theoretical power/kg steam/s is = %f kW\n',W);
+
+// (b)
+// from steam table
+hf6 = 251.5;// [kJ/kg]
+
+TE1 = ((h1-h2)+(h3-h4)+(h5-h6))/((h1-hf6)+(h3-h2)+(h5-h4));// thermal efficiency
+mprintf('\n (b) The thermal efficiency of the cycle is = %f percent\n',TE1*100);
+
+// (c)
+// if there is no heat
+hf7 = hf6;
+TE2 = (h1-h7)/(h1-hf7);// thermal efficiency
+mprintf('\n (c) The thermal efficiency of the cycle if there is no heat is = %f percent\n',TE2*100);
+
+// End
diff --git a/2705/CH11/EX11.1/Ex11_1.sce b/2705/CH11/EX11.1/Ex11_1.sce new file mode 100755 index 000000000..973fd235e --- /dev/null +++ b/2705/CH11/EX11.1/Ex11_1.sce @@ -0,0 +1,45 @@ +clear;
+clc;
+disp('Example 11.1')
+
+// aim : To determine the
+// (a) bore of the cylinder
+// (b) piston stroke
+// (c) speed of the engine
+
+// Given values
+P_req = 60;// power required to develop, [kW]
+P = 1.25;// boiler pressure, [MN/m^2]
+Pb = .13;// back pressure, [MN/m^2]
+cut_off = .3;// [stroke]
+k = .82;// diagram factor
+n = .78;// mechanical efficiency
+LN = 3;// mean piston speed, [m/s]
+
+// solution
+// (a)
+r = 1/cut_off;// expansion ratio
+Pm = P/r*(1+log(r))-Pb;// mean effective pressure, [MN/m^2]
+P_ind = P_req/n;// Actual indicated power developed, [kW]
+P_the = P_ind/k;// Theoretical indicated power developed, [kW]
+
+// using indicated_power=Pm*LN*A
+// Hence
+A = P_the/(Pm*LN)*10^-3;// piston area,[m^2]
+d = sqrt(4*A/%pi)*10^3;// bore ,[mm]
+mprintf('\n (a) The bore of the cylinder is = %f mm\n',d);
+
+// (b)
+// given that stroke is 1.25 times bore
+L = 1.25*d;// [mm]
+mprintf('\n (b) The piston stroke is = %f mm\n',L);
+
+// (c)
+// LN=mean piston speed, where L is stroke in meter and N is 2*rev/s,(since engine is double_acting)
+// hence
+rev_per_sec = LN/(2*L*10^-3);// [rev/s]
+
+rev_per_min = rev_per_sec*60;// [rev/min]
+mprintf('\n (c) The speed of the engine is = %f rev/min\n',rev_per_min);
+
+// End
diff --git a/2705/CH11/EX11.2/Ex11_2.sce b/2705/CH11/EX11.2/Ex11_2.sce new file mode 100755 index 000000000..e7f862fc2 --- /dev/null +++ b/2705/CH11/EX11.2/Ex11_2.sce @@ -0,0 +1,51 @@ +clear;
+clc;
+disp('Example 11.2')
+
+// aim : To determine the
+// (a) the diameter of the cylinder
+// (b) piston stroke
+// (c) actual steam consumption and indicated thermal efficiency
+
+// Given values
+P = 900;// inlet pressure, [kN/m^2]
+Pb = 140;// exhaust pressure, [kN/m^2]
+cut_off =.4;// [stroke]
+k = .8;// diagram factor
+rs = 1.2;// stroke to bore ratio
+N = 4;// engine speed, [rev/s]
+ip = 22.5;// power output from the engine, [kW]
+
+// solution
+// (a)
+r = 1/cut_off;// expansion ratio
+Pm = P/r*(1+log(r))-Pb;// mean effective pressure, [kN/m^2]
+Pm = Pm*k;// actual mean effective pressure, [kN/m^2]
+
+// using ip=Pm*L*A*N
+// and L=r*d; where L is stroke and d is bore
+d = (ip/(Pm*rs*%pi/4*2*N))^(1/3);// diameter of the cylinder, [m]
+
+mprintf('\n (a) The diameter of the cylinder is = %f mm\n',d*1000);
+
+// (b)
+L = rs*d;// stroke, [m]
+mprintf('\n (b) The piston stroke is = %f mm\n',L*1000);
+
+// (c)
+SV = %pi/4*d^2*L;// stroke volume, [m^3]
+V = SV*cut_off*2*240*60;// volume of steam consumed per hour, [m^3]
+v = .2148;// specific volume at 900 kN/m^2, [m^3/kg]
+SC = V/v;// steam consumed/h, [kg]
+ASC = 1.5*SC;// actual steam consumption/h, [kg]
+mprintf('\n (c) The actual steam consumption/h is = %f kg\n',ASC);
+
+m_dot = ASC/3600;// steam consumption,[kg/s]
+// from steam table
+hg = 2772.1;// specific enthalpy of inlet steam, [kJ/kg]
+hfe = 458.4;// specific liquid enthalpy at exhaust pressure, [kJ/kg]
+
+ITE = ip/(m_dot*(hg-hfe));// indicated thermal efficiency
+mprintf('\n The indicated thermal efficiency is = %f percent\n',ITE*100);
+
+// End
diff --git a/2705/CH11/EX11.3/Ex11_3.sce b/2705/CH11/EX11.3/Ex11_3.sce new file mode 100755 index 000000000..14b2cf23b --- /dev/null +++ b/2705/CH11/EX11.3/Ex11_3.sce @@ -0,0 +1,41 @@ +clear;
+clc;
+disp('Example 11.3');
+
+// aim : To determine
+// (a) the diagram factor
+// (b) the indicated thermal efficiency of the engine
+
+// given values
+d = 250*10^-3;// cylinder diameter, [m]
+L = 375*10^-3;// length of stroke, [m]
+P = 1000;// steam pressure , [kPa]
+x = .96;// dryness fraction of steam
+Pb = 55;// exhaust pressure, [kPa]
+r = 6;// expansion ratio
+ip = 45;// indicated power developed, [kW]
+N = 3.5;// speed of engine, [rev/s]
+m = 460;// steam consumption, [kg/h]
+
+// solution
+// (a)
+Pm = P/r*(1+log(r))-Pb;// [kN/m^3]
+A = %pi*(d)^2/4;// area, [m^2]
+tip = Pm*L*A*N*2;// theoretical indicated power, [kW]
+k = ip/tip;// diagram factor
+mprintf('\n (a) The diagram factor is = %f\n',k);
+
+// (b)
+// from steam table at 1 MN/m^2
+hf = 762.6;// [kJ/kg]
+hfg = 2013.6;// [kJ/kg]
+// so
+h1 = hf+x*hfg;// specific enthalpy of steam at 1MN/m^2, [kJ/kg]
+// minimum specific enthalpy in engine at 55 kPa
+hf = 350.6;// [kJ/kg]
+// maximum energy available in engine is
+h = h1-hf;// [kJ/kg]
+ITE = ip/(m*h/3600)*100;// indicated thermal efficiency
+mprintf('\n (b) The indicated thermal efficiency is = %f percent\n ',ITE);
+
+// End
diff --git a/2705/CH11/EX11.4/Ex11_4.sce b/2705/CH11/EX11.4/Ex11_4.sce new file mode 100755 index 000000000..4e480bf97 --- /dev/null +++ b/2705/CH11/EX11.4/Ex11_4.sce @@ -0,0 +1,20 @@ +clear;
+clc;
+disp('Example 11.4');
+
+// aim : To determine
+// steam consumption
+
+// given values
+P1 = 11;// power, [kW]
+m1 = 276;// steam use/h when developing power P1,[kW]
+ip = 8;// indicated power output, [kW]
+B = 45;// steam used/h at no load, [kg]
+
+// solution
+// using graph of Fig.11.9
+A = (m1-B)/P1;// slop of line, [kg/kWh]
+W = A*ip+B;// output, [kg/h]
+mprintf('\n The steam consumption is = %f kg/h\n ',W);
+
+// End
diff --git a/2705/CH11/EX11.5/Ex11_5.sce b/2705/CH11/EX11.5/Ex11_5.sce new file mode 100755 index 000000000..b4106e20d --- /dev/null +++ b/2705/CH11/EX11.5/Ex11_5.sce @@ -0,0 +1,52 @@ +clear;
+clc;
+disp('Example 11.5');
+
+// aim : To determine
+// (a) the intermediate pressure
+// (b) the indicated power output
+// (c) the steam consumption of the engine
+
+// given values
+P1 = 1400;// initial pressure, [kN/m^2]
+x = .9;// dryness fraction
+P5 = 35;// exhaust pressure
+k = .8;// diagram factor of low-pressure cylindaer
+L = 350*10^-3;// stroke of both the cylinder, [m]
+dhp = 200*10^-3;// diameter of high pressure cylinder, [m]
+dlp = 300*10^-3;// diameter of low-pressure cylinder, [m]
+N = 300;// engine speed, [rev/min]
+
+// solution
+// taking reference Fig.11.13
+Ahp = %pi/4*dhp^2;// area of high-pressure cylinder, [m^2]
+Alp = %pi/4*dlp^2;// area of low-pressure cylinder, [m^2]
+// for equal initial piston loads
+// (P1-P7)Ahp=(P7-P5)Alp
+deff('[x]=f(P7)','x=(P1-P7)*Ahp-(P7-P5)*Alp');
+P7 = fsolve(0,f);// intermediate pressure, [kN/m^2]
+mprintf('\n (a) The intermediate pressure is = %f kN/m^2\n ',P7);
+
+// (b)
+V6 = Ahp*L;// volume of high-pressure cylinder, [m^3]
+P2 = P1;
+P6 = P7;
+// using P2*V2=P6*V6
+V2 = P6*V6/P2; // [m^3]
+V1 = Alp*L;// volume of low-pressure cylinder, [m^3]
+R = V1/V2;// expansion ratio
+Pm = P1/R*(1+log(R))-P5;// effective pressure of low-pressure cylinder, [kn/m^2]
+Pm = k*Pm;// actual effective pressure, [kN/m^2]
+ip = Pm*L*Alp*N*2/60;// indicated power, [kW]
+mprintf('\n (b) The indicated power is = %f kW\n',ip);
+
+// (c)
+COV = V1/ R;// cut-off volume in high-pressure cylinder, [m^3]
+V = COV*N*2*60;// volume of steam admitted/h
+// from steam table
+vg = .1407;// [m^3/kg]
+AV = x*vg;// specific volume of admission steam, [m^3/kg]
+m = V/AV;// steam consumption, [kg/h]
+mprintf('\n (c) The steam consumption of the engine is = %f kg/h\n',m);
+
+// End
diff --git a/2705/CH11/EX11.6/Ex11_6.sce b/2705/CH11/EX11.6/Ex11_6.sce new file mode 100755 index 000000000..5cbaf958a --- /dev/null +++ b/2705/CH11/EX11.6/Ex11_6.sce @@ -0,0 +1,45 @@ +clear;
+clc;
+disp('Example 11.6');
+
+// aim : To determine
+// (a) the indicated power output
+// (b) the diameter of high-pressure cylinder of the engine
+// (c) the intermediate pressure
+
+// given values
+P = 1100;// initial pressure, [kN/m^2]
+Pb = 28;// exhaust pressure
+k = .82;// diagram factor of low-pressure cylindaer
+L = 600*10^-3;// stroke of both the cylinder, [m]
+dlp = 600*10^-3;// diameter of low-pressure cylinder, [m]
+N = 4;// engine speed, [rev/s]
+R = 8;// expansion ratio
+
+// solution
+// taking reference Fig.11.13
+// (a)
+Pm = P/R*(1+log(R))-Pb;// effective pressure of low-pressure cylinder, [kn/m^2]
+Pm = k*Pm;// actual effective pressure, [kN/m^2]
+Alp = %pi/4*dlp^2;// area of low-pressure cylinder, [m^2]
+ip = Pm*L*Alp*N*2;// indicated power, [kW]
+mprintf('\n (a) The indicated power is = %f kW\n',ip);
+
+// (b)
+// work done by both cylinder is same as area of diagram
+w = Pm*Alp*L;// [kJ]
+W = w/2;// work done/cylinder, [kJ]
+V2 = Alp*L/8;// volume, [m63]
+P2 = P;// [kN/m^2]
+// using area A1267=P2*V2*log(V6/V2)=W
+V6 = V2*exp(W/(P2*V2));// intermediate volume, [m^3]
+// using Ahp*L=%pi/4*dhp^2*L=V6
+dhp = sqrt(V6*4/L/%pi);// diameter of high-pressure cylinder, [m]
+mprintf('\n (b) The diameter of high-pressure cylinder is = %f mm\n',dhp*1000);
+
+// (c)
+// using P2*V2=P6*V6
+P6 = P2*V2/V6; // intermediate pressure, [kN/m^2]
+mprintf('\n (c) The intermediate opressure is = %f kN/m^2\n',P6);
+
+// End
diff --git a/2705/CH11/EX11.7/Ex11_7.sce b/2705/CH11/EX11.7/Ex11_7.sce new file mode 100755 index 000000000..da5f5dd4e --- /dev/null +++ b/2705/CH11/EX11.7/Ex11_7.sce @@ -0,0 +1,37 @@ +clear;
+clc;
+disp('Example 11.7');
+
+// aim : To determine
+// (a) The speed of the engine
+// (b) the diameter of the high pressure cylinder
+
+// given values
+ip = 230;// indicated power, [kW]
+P = 1400;// admission pressure, [kN/m^2]
+Pb = 35;// exhaust pressure, [kN/m^2]
+R = 12.5;// expansion ratio
+d1 = 400*10^-3;// diameter of low pressure cylinder, [m]
+L = 500*10^-3;// stroke of both the cylinder, [m]
+k = .78;// diagram factor
+rv = 2.5;// expansion ratio of high pressure cylinder
+
+// solution
+// (a)
+Pm = P/R*(1+log(R))-Pb;// mean effective pressure in low pressure cylinder, [kN/m^2]
+ipt = ip/k;// theoretical indicated power, [kw]
+// using ip=Pm*L*A*N
+A = %pi/4*d1^2;// area , [m^2]
+N = ipt/(Pm*L*A*2);// speed, [rev/s]
+mprintf('\n (a) The engine speed is = %f rev/s\n',N);
+
+// (b)
+Vl = A*L;// volume of low pressure cylinder, [m^3]
+COV = Vl/R;// cutt off volume of hp cylinder, [m^3]
+V = COV*rv;// total volume, [m^3]
+
+// V = %pi/4*d^2*L, so
+d = sqrt(4*V/%pi/L);// diameter of high pressure cylinder, [m]
+mprintf('\n (b) The diameter of the high pressure cylinder is = %f mm\n',d*1000);
+
+// End
diff --git a/2705/CH11/EX11.8/Ex11_8.sce b/2705/CH11/EX11.8/Ex11_8.sce new file mode 100755 index 000000000..4189dbf58 --- /dev/null +++ b/2705/CH11/EX11.8/Ex11_8.sce @@ -0,0 +1,54 @@ +clear;
+clc;
+disp('Example 11.8');
+
+// aim : To determine
+// (a) the actual and hypothetical mean effective pressures referred to the low-pressure cylinder
+// (b) the overall diagram factor
+// (c) the indicated power
+
+// given values
+P = 1100;// steam supply pressure, [kN/m^2]
+Pb = 32;// back pressure, [kN/m^2]
+d1 = 300*10^-3;// cylinder1 diameter, [m]
+d2 = 600*10^-3;// cylinder2 diameter, [m]
+L = 400*10^-3;// common stroke of both cylinder, [m]
+
+A1 = 12.5;// average area of indicated diagram for HP, [cm^2]
+A2 = 11.4;// average area of indicated diagram for LP, [cm^2]
+
+P1 = 270;// indicator calibration, [kN/m^2/ cm]
+P2 = 80;// spring calibration, [kN/m^2/ cm]
+N = 2.7;// engine speed, [rev/s]
+l = .75;// length of both diagram, [m]
+
+// solution
+// (a)
+// for HP cylinder
+Pmh = P1*A1/7.5;// [kN/m^2]
+F = Pmh*%pi/4*d1^2;// force on HP, [kN]
+PmH = Pmh*(d1/d2)^2;// pressure referred to LP cylinder, [kN/m^2]
+PmL = P2*A2/7.5;// pressure for LP cylinder, [kN/m^2]
+PmA = PmH+PmL;// actual effective pressure referred to LP cylinder, [kN/m^2]
+
+Ah = %pi/4*d1^2;// area of HP cylinder, [m^2]
+Vh = Ah*L;// volume of HP cylinder, [m^3]
+CVh = Vh/3;// cut-off volume of HP cylinder, [m^3]
+Al = %pi/4*d2^2;// area of LP cylinder, [m^2]
+Vl = Al*L;// volume of LP cylinder, [m^3]
+
+R = Vl/CVh;// expansion ratio
+Pm = P/R*(1+log(R))-Pb;// hypothetical mean effective pressure referred to LP cylinder, [kN/m^2]
+
+mprintf('\n (a) The actual mean effective pressure referred to LP cylinder is = %f kN/m^2\n',PmA);
+mprintf('\n The hypothetical mean effective pressure referred to LP cylinder is = %f kN/m^2\n',Pm);
+
+// (a)
+ko = PmA/Pm;// overall diagram factor
+mprintf('\n (b) The overall diagram factor is = %f\n',ko);
+
+// (c)
+ip = PmA*L*Al*N*2;// indicated power, [kW]
+mprintf('\n (c) The indicated power is = %f kW\n',ip);
+
+// End
diff --git a/2705/CH11/EX11.9/Ex11_9.sce b/2705/CH11/EX11.9/Ex11_9.sce new file mode 100755 index 000000000..e020aaa3e --- /dev/null +++ b/2705/CH11/EX11.9/Ex11_9.sce @@ -0,0 +1,48 @@ +clear;
+clc;
+disp('Example 11.9');
+
+// aim : To determine
+// (a) the actual and hypothetical mean effective pressures referred to the low-pressure cylinder
+// (b) the overall diagram factor
+// (c) the pecentage of the total indicated power developed in each cylinder
+
+// given values
+P = 1400;// steam supply pressure, [kN/m^2]
+Pb = 20;// back pressure, [kN/m^2]
+Chp = .6;// cut-off in HP cylinder, [stroke]
+dh = 300*10^-3;// HP diameter, [m]
+di = 500*10^-3;// IP diameter, [m]
+dl = 900*10^-3;// LP diameter, [m]
+
+Pm1 = 590;// actual pressure of HP cylinder, [kN/m^2]
+Pm2 = 214;// actual pressure of IP cylinder, [kN/m^2]
+Pm3 = 88;// actual pressure of LP cylinder, [kN/m^2]
+
+// solution
+// (a)
+// for HP cylinder
+PmH = Pm1*(dh/dl)^2;// PmH referred to LP cylinder, [kN/m^2]
+// for IP cylinder
+PmI = Pm2*(di/dl)^2;// PmI referred to LP cylinder, [kN/m^2]
+PmA = PmH+PmI+Pm3;// actual mean effective pressure referred to LP cylinder, [kN/m^2]
+
+R = dl^2/(dh^2*Chp);// expansion ratio
+Pm = P/R*(1+log(R))-Pb;// hypothetical mean effective pressure referred to LP cylinder, [kN/m^2]
+
+mprintf('\n (a) The actual mean effective pressure referred to LP cylinder is = %f kN/m^2\n',PmA);
+mprintf('\n The hypothetical mean effective pressure referred to LP cylinder is = %f kN/m^2\n',Pm);
+
+// (b)
+ko = PmA/Pm;// overall diagram factor
+mprintf('\n (b) The overall diagram factor is = %f\n',ko);
+
+// (c)
+HP = PmH/PmA*100;// %age of indicated power developed in HP
+IP = PmI/PmA*100; // %age of indicated power developed in IP
+LP = Pm3/PmA*100; // %age of indicated power developed in LP
+mprintf('\n (c) The pecentage of the total indicated power developed in HP cylinder is = %f percent\n',HP);
+mprintf('\n The pecentage of the total indicated power developed in IP cylinder is = %f percent\n',IP);
+mprintf('\n The pecentage of the total indicated power developed in LP cylinder is = %f percent\n',LP);
+
+// End
diff --git a/2705/CH12/EX12.1/Ex12_1.sce b/2705/CH12/EX12.1/Ex12_1.sce new file mode 100755 index 000000000..6acd59e30 --- /dev/null +++ b/2705/CH12/EX12.1/Ex12_1.sce @@ -0,0 +1,43 @@ +clear;
+clc;
+disp('Example 12.1');
+
+// aim : To determine the
+// (a) throat area
+// (b) exit area
+// (c) Mach number at exit
+
+// Given values
+P1 = 3.5;// inlet pressure of air, [MN/m^2]
+T1 = 273+500;// inlet temperature of air, [MN/m^2]
+P2 = .7;// exit pressure, [MN/m^2]
+m_dot = 1.3;// flow rate of air, [kg/s]
+Gamma = 1.4;// heat capacity ratio
+R = .287;// [kJ/kg K]
+
+// solution
+// given expansion may be considered to be adiabatic and to follow the law PV^Gamma=constant
+// using ideal gas law
+v1 = R*T1/P1*10^-3;// [m^3/kg]
+Pt = P1*(2/(Gamma+1))^(Gamma/(Gamma-1));// critical pressure, [MN/m^2]
+
+// velocity at throat is
+Ct = sqrt(2*Gamma/(Gamma-1)*P1*10^6*v1*(1-(Pt/P1)^(((Gamma-1)/Gamma))));// [m/s]
+vt = v1*(P1/Pt)^(1/Gamma);// [m^3/kg]
+// using m_dot/At=Ct/vt
+At = m_dot*vt/Ct*10^6;// throat area, [mm^2]
+mprintf('\n (a) The throat area is = %f mm^2\n',At);
+
+// (b)
+// at exit
+C2 = sqrt(2*Gamma/(Gamma-1)*P1*10^6*v1*(1-(P2/P1)^(((Gamma-1)/Gamma))));// [m/s]
+v2 = v1*(P1/P2)^(1/Gamma);// [m^3/kg]
+A2 = m_dot*v2/C2*10^6;// exit area, [mm^2]
+
+mprintf('\n (b) The exit area is = %f mm^2\n',A2);
+
+// (c)
+M = C2/Ct;
+mprintf('\n (c) The Mach number at exit is = %f\n',M);
+
+// End
diff --git a/2705/CH12/EX12.2/Ex12_2.sce b/2705/CH12/EX12.2/Ex12_2.sce new file mode 100755 index 000000000..fd3cd191b --- /dev/null +++ b/2705/CH12/EX12.2/Ex12_2.sce @@ -0,0 +1,33 @@ +clear;
+clc;
+disp('Example 12.2');
+
+// aim : To determine the increases in pressure, temperature and internal energy per kg of air
+
+// Given values
+T1 = 273;// [K]
+P1 = 140;// [kN/m^2]
+C1 = 900;// [m/s]
+C2 = 300;// [m/s]
+cp = 1.006;// [kJ/kg K]
+cv =.717;// [kJ/kg K]
+
+// solution
+R = cp-cv;// [kJ/kg K]
+Gamma = cp/cv;// heat capacity ratio
+// for frictionless adiabatic flow, (C2^2-C1^2)/2=Gamma/(Gamma-1)*R*(T1-T2)
+
+T2 =T1-((C2^2-C1^2)*(Gamma-1)/(2*Gamma*R))*10^-3; // [K]
+T_inc = T2-T1;// increase in temperature [K]
+
+P2 = P1*(T2/T1)^(Gamma/(Gamma-1));// [MN/m^2]
+P_inc = (P2-P1)*10^-3;// increase in pressure,[MN/m^2]
+
+U_inc = cv*(T2-T1);// Increase in internal energy per kg,[kJ/kg]
+mprintf('\n The increase in pressure is = %f MN/m^2\n',P_inc);
+mprintf('\n Increase in temperature is = %f K\n',T_inc);
+mprintf('\n Increase in internal energy is = %f kJ/kg\n',U_inc);
+
+// there is minor variation in result
+
+// End
diff --git a/2705/CH12/EX12.3/Ex12_3.sce b/2705/CH12/EX12.3/Ex12_3.sce new file mode 100755 index 000000000..37084b47a --- /dev/null +++ b/2705/CH12/EX12.3/Ex12_3.sce @@ -0,0 +1,47 @@ +clear;
+clc;
+disp('Example 12.3');
+
+// aim : To determine the
+// (a) throat and exit areas
+// (b) degree of undercooling at exit
+// Given values
+P1 = 2;// inlet pressure of air, [MN/m^2]
+T1 = 273+325;// inlet temperature of air, [MN/m^2]
+P2 = .36;// exit pressure, [MN/m^2]
+m_dot = 7.5;// flow rate of air, [kg/s]
+n = 1.3;// polytropic index
+
+// solution
+// (a)
+// using steam table
+v1 = .132;// [m^3/kg]
+// given expansion following law PV^n=constant
+
+Pt = P1*(2/(n+1))^(n/(n-1));// critical pressure, [MN/m^2]
+
+//velocity at throat is
+Ct = sqrt(2*n/(n-1)*P1*10^6*v1*(1-(Pt/P1)^(((n-1)/n))));// [m/s]
+vt = v1*(P1/Pt)^(1/n);// [m^3/kg]
+// using m_dot/At=Ct/vt
+At = m_dot*vt/Ct*10^6;// throat area, [mm^2]
+mprintf('\n (a) The throat area is = %f mm^2\n',At);
+
+// at exit
+C2 = sqrt(2*n/(n-1)*P1*10^6*v1*(1-(P2/P1)^(((n-1)/n))));// [m/s]
+v2 = v1*(P1/P2)^(1/n);// [m^3/kg]
+A2 = m_dot*v2/C2*10^6;// exit area, [mm^2]
+
+mprintf('\n The exit area is = %f mm^2\n',A2);
+
+// (b)
+T2 = T1*(P2/P1)^((n-1)/n);//outlet temperature, [K]
+t2 = T2-273;//[C]
+// at exit pressure saturation temperature is
+ts = 139.9;// saturation temperature,[C]
+Doc = ts-t2;// Degree of undercooling,[C]
+mprintf('\n (b) The Degree of undercooling at exit is = %f C\n',Doc);
+
+// There is some calculation mistake in the book so answer is not matching
+
+// End
diff --git a/2705/CH12/EX12.4/Ex12_4.sce b/2705/CH12/EX12.4/Ex12_4.sce new file mode 100755 index 000000000..0bc59c65e --- /dev/null +++ b/2705/CH12/EX12.4/Ex12_4.sce @@ -0,0 +1,48 @@ +clear;
+clc;
+disp('Example 12.4');
+
+// aim : To determine the
+// (a) throat and exit velocities
+// (b) throat and exit areas
+
+// Given values
+P1 = 2.2;// inlet pressure, [MN/m^2]
+T1 = 273+260;// inlet temperature, [K]
+P2 = .4;// exit pressure,[MN/m^2]
+eff = .85;// efficiency of the nozzle after throat
+m_dot = 11;// steam flow rate in the nozzle, [kg/s]
+
+// solution
+// (a)
+// assuming steam is following same law as previous question 12.3
+Pt = .546*P1;// critical pressure,[MN/m^2]
+// from Fig. 12.6
+h1 = 2940;// [kJ/kg]
+ht = 2790;// [kJ/kg]
+
+Ct = sqrt(2*(h1-ht)*10^3);// [m/s]
+
+// again from Fig. 12.6
+h2_prime = 2590;// [kJ/kg]
+// using eff = (ht-h2)/(ht-h2_prime)
+
+h2 = ht-eff*(ht-h2_prime); // [kJ/kg]
+
+C2 = sqrt(2*(h1-h2)*10^3);// [m/s]
+
+// (b)
+// from chart
+vt = .16;// [m^3/kg]
+v2 = .44;// [m^3/kg]
+// using m_dot*v=A*C
+At = m_dot*vt/Ct*10^6;// throat area, [mm^2]
+
+A2 = m_dot*v2/C2*10^6;// throat area, [mm^2]
+
+mprintf('\n (a) The throat velocity is = %f m/s\n',Ct);
+mprintf('\n The exit velocity is = %f m/s\n',C2);
+mprintf('\n (b) The throat area is = %f mm^2\n',At);
+mprintf('\n The throat area is = %f mm^2\n',A2);
+
+// End
diff --git a/2705/CH13/EX13.1/Ex13_1.sce b/2705/CH13/EX13.1/Ex13_1.sce new file mode 100755 index 000000000..55203b728 --- /dev/null +++ b/2705/CH13/EX13.1/Ex13_1.sce @@ -0,0 +1,24 @@ +clear;
+clc;
+disp('Example 13.1');
+
+// aim : To determine
+// the power developed for a steam flow of 1 kg/s at the blades and the kinetic energy of the steam finally leaving the wheel
+
+// Given values
+alfa = 20;// blade angle, [degree]
+Cai = 375;// steam exit velocity in the nozzle,[m/s]
+U = 165;// blade speed, [m/s]
+loss = .15;// loss of velocity due to friction
+
+// solution
+// using Fig13.12,
+Cvw = 320;// change in velocity of whirl, [m/s]
+cae = 132.5;// absolute velocity at exit, [m/s]
+Pds = U*Cvw*10^-3;// Power developed for steam flow of 1 kg/s, [kW]
+Kes = cae^2/2*10^-3;// Kinetic energy change of steam, [kW/kg]
+
+mprintf('\n The power developed for a steam flow of 1 kg/s is = %f kW\n',Pds)
+mprintf('\n The energy of steam finally leaving the wheel is = %f kW/kg\n',Kes);
+
+// End
diff --git a/2705/CH13/EX13.2/Ex13_2.sce b/2705/CH13/EX13.2/Ex13_2.sce new file mode 100755 index 000000000..601a28f65 --- /dev/null +++ b/2705/CH13/EX13.2/Ex13_2.sce @@ -0,0 +1,38 @@ +clear;
+clc;
+disp('Example 13.2');
+
+// aim : To determine
+// (a) the entry angle of the blades
+// (b) the work done per kilogram of steam per second
+// (c) the diagram efficiency
+// (d) the end-thrust per kilogram of steam per second
+
+// given values
+Cai = 600;// steam velocity, [m/s]
+sia = 25;// steam inlet angle with blade, [degree]
+U = 255;// mean blade speed, [m/s]
+sea = 30;// steam exit angle with blade,[degree]
+
+// solution
+// (a)
+// using Fig.13.13(diagram for example 13.2)
+eab = 41.5;// entry angle of blades, [degree]
+mprintf('\n (a) The angle of blades is = %f degree\n',eab);
+
+// (b)
+Cwi_plus_Cwe = 590;// velocity of whirl, [m/s]
+W = U*(Cwi_plus_Cwe);// work done on the blade,[W/kg]
+mprintf('\n (b) The work done on the blade is = %f kW/kg\n',W*10^-3);
+
+// (c)
+De = 2*U*(Cwi_plus_Cwe)/Cai^2;// diagram efficiency
+mprintf('\n (c) The diagram efficiency is = %f percent\n',De*100);
+
+// (d)
+// again from the diagram
+Cfe_minus_Cfi = -90;// change invelocity of flow, [m/s]
+Eth = Cfe_minus_Cfi;// end-thrust, [N/kg s]
+mprintf('\n (d) The End-thrust is = %f N/kg',Eth);
+
+// End
diff --git a/2705/CH13/EX13.3/Ex13_3.sce b/2705/CH13/EX13.3/Ex13_3.sce new file mode 100755 index 000000000..511e4e183 --- /dev/null +++ b/2705/CH13/EX13.3/Ex13_3.sce @@ -0,0 +1,28 @@ +clear;
+clc;
+disp('Example 13.3');
+
+// aim : To determine
+// (a) the power output of the turbine
+// (b) the diagram efficiency
+
+// given values
+U = 150;// mean blade speed, [m/s]
+Cai1 = 675;// nozzle speed, [m/s]
+na = 20;// nozzle angle, [degree]
+m_dot = 4.5;// steam flow rate, [kg/s]
+
+// solution
+// from Fig. 13.15(diagram 13.3)
+Cw1 = 915;// [m/s]
+Cw2 = 280;// [m/s]
+
+// (a)
+P = m_dot*U*(Cw1+Cw2);// power of turbine,[W]
+mprintf('\n (a) The power of turbine is = %f kW\n',P*10^-3);
+
+// (b)
+De = 2*U*(Cw1+Cw2)/Cai1^2;// diagram efficiency
+mprintf('\n (b) The diagram efficiency is = %f percent\n',De*100);
+
+// End
diff --git a/2705/CH13/EX13.4/Ex13_4.sce b/2705/CH13/EX13.4/Ex13_4.sce new file mode 100755 index 000000000..2f9f9c42a --- /dev/null +++ b/2705/CH13/EX13.4/Ex13_4.sce @@ -0,0 +1,37 @@ +clear;
+clc;
+disp('Example 13.4');
+
+// aim : To determine
+// (a) the power output of the stage
+// (b) the specific enthalpy drop in the stage
+// (c) the percentage increase in relative velocity in the moving blades due to expansion in the bladse
+
+// given values
+N = 50;// speed, [m/s]
+d = 1;// blade ring diameter, [m]
+nai = 50;// nozzle inlet angle, [degree]
+nae = 30;// nozzle exit angle, [degree]
+m_dot = 600000;// steam flow rate, [kg/h]
+se = .85;// stage efficiency
+
+// solution
+// (a)
+U = %pi*d*N;// mean blade speed, [m/s]
+// from Fig. 13.17(diagram 13.4)
+Cwi_plus_Cwe = 444;// change in whirl speed, [m/s]
+P = m_dot*U*Cwi_plus_Cwe/3600;// power output of the stage, [W]
+mprintf('\n (a) The power output of the stage is = %f MW\n',P*10^-6);
+
+// (b)
+h = U*Cwi_plus_Cwe/se;// specific enthalpy,[J/kg]
+mprintf('\n (b) The specific enthalpy drop in the stage is = %f kJ/kg\n ',h*10^-3);
+
+// (c)
+// again from diagram
+Cri = 224;// [m/s]
+Cre = 341;// [m/s]
+Iir = (Cre-Cri)/Cri;// increase in relative velocity
+mprintf('\n (c) The increase in relative velocity is = %f percent\n',Iir*100);
+
+// End
diff --git a/2705/CH13/EX13.5/Ex13_5.sce b/2705/CH13/EX13.5/Ex13_5.sce new file mode 100755 index 000000000..b2c3c6672 --- /dev/null +++ b/2705/CH13/EX13.5/Ex13_5.sce @@ -0,0 +1,36 @@ +clear;
+clc;
+disp('Example 13.5');
+
+// aim : To determine
+// (a) the blade height of the stage
+// (b) the power developed in the stage
+// (c) the specific enthalpy drop at the stage
+
+// given values
+U = 60;// mean blade speed, [m/s]
+P = 350;// steam pressure, [kN/m^2]
+T = 175;// steam temperature, [C]
+nai = 30;// stage inlet angle, [degree]
+nae = 20;// stage exit angle, [degree]
+
+// solution
+// (a)
+m_dot = 13.5;// steam flow rate, [kg/s]
+// at given T and P
+v = .589;// specific volume, [m^3/kg]
+// given H=d/10, so
+H = sqrt(m_dot*v/(%pi*10*60));// blade height, [m]
+mprintf('\n (a) The blade height at this stage is = %f mm\n',H*10^3);
+
+// (b)
+Cwi_plus_Cwe = 270;// change in whirl speed, [m/s]
+P = m_dot*U*(Cwi_plus_Cwe);// power developed, [W]
+mprintf('\n (b) The power developed is = %f kW\n',P*10^-3);
+
+// (c)
+s = .85;// stage efficiency
+h = U*Cwi_plus_Cwe/s;// specific enthalpy,[J/kg]
+mprintf('\n (a) The specific enthalpy drop in the stage is = %f kJ/kg',h*10^-3);
+
+// End
diff --git a/2705/CH14/EX14.1/Ex14_1.sce b/2705/CH14/EX14.1/Ex14_1.sce new file mode 100755 index 000000000..404a8d8d4 --- /dev/null +++ b/2705/CH14/EX14.1/Ex14_1.sce @@ -0,0 +1,55 @@ +clear;
+clc;
+disp(' Example 14.1');
+
+// aim : To determine
+// (a) the free air delivered
+// (b) the volumetric efficiency
+// (c) the air delivery temperature
+// (d) the cycle power
+// (e) the isothermal efficiency
+
+// given values
+d = 200*10^-3;// bore, [m]
+L = 300*10^-3;// stroke, [m]
+N = 500;// speed, [rev/min]
+n = 1.3;// polytropic index
+P1 = 97;// intake pressure, [kN/m^2]
+T1 = 273+20;// intake temperature, [K]
+P3 = 550;// compression pressure, [kN/m^2]
+
+// solution
+// (a)
+P4 = P1;
+P2 = P3;
+Pf = 101.325;// free air pressure, [kN/m^2]
+Tf = 273+15;// free air temperature, [K]
+SV = %pi/4*d^2*L;// swept volume, [m^3]
+V3 = .05*SV;// [m^3]
+V1 = SV+V3;// [m^3]
+V4 = V3*(P3/P4)^(1/n);// [m^3]
+ESV = (V1-V4)*N;// effective swept volume/min, [m^3]
+// using PV/T=constant
+Vf = P1*ESV*Tf/(Pf*T1);// free air delivered, [m^3/min]
+mprintf('\n (a) The free air delivered is = %f m^3/min\n',Vf);
+
+// (b)
+VE = Vf/(N*(V1-V3));// volumetric efficiency
+mprintf('\n (b) The volumetric efficiency is = %f percent\n',VE*100);
+
+// (c)
+T2 = T1*(P2/P1)^((n-1)/n);// free air temperature, [K]
+mprintf('\n (c) The air delivery temperature is = %f C\n',T2-273);
+
+// (d)
+CP = n/(n-1)*P1*(V1-V4)*((P2/P1)^((n-1)/n)-1)*N/60;// cycle power, [kW]
+ mprintf('\n (d) The cycle power is = %f kW\n',CP);
+
+// (e)
+// neglecting clearence
+W = n/(n-1)*P1*V1*((P2/P1)^((n-1)/n)-1)
+Wi = P1*V1*log(P2/P1);// isothermal efficiency
+IE = Wi/W;// isothermal efficiency
+mprintf('\n (e) The isothermal efficiency neglecting clearence is = %f percent\n',IE*100);
+
+// End
diff --git a/2705/CH14/EX14.2/Ex14_2.sce b/2705/CH14/EX14.2/Ex14_2.sce new file mode 100755 index 000000000..ec512aa18 --- /dev/null +++ b/2705/CH14/EX14.2/Ex14_2.sce @@ -0,0 +1,35 @@ +clear;
+clc;
+disp(' Example 14.2');
+
+// aim : To determine
+// (a) the intermediate pressure
+// (b) the total volume of each cylinder
+// (c) the cycle power
+
+// given values
+v1 = .2;// air intake, [m^3/s]
+P1 = .1;// intake pressure, [MN/m^2]
+T1 = 273+16;// intake temperature, [K]
+P3 = .7;// final pressure, [MN/m^2]
+n = 1.25;// compression index
+N = 10;// speed, [rev/s]
+
+// solution
+// (a)
+P2 = sqrt(P1*P3);// intermediate pressure, [MN/m^2]
+mprintf('\n (a) The intermediate pressure is = %f MN/m^2\n',P2);
+
+// (b)
+V1 = v1/N;// total volume,[m^3]
+// since intercooling is perfect so 2 lie on the isothermal through1, P1*V1=P2*V2
+V2 = P1*V1/P2;// volume, [m^3]
+mprintf('\n (b) The total volume of the HP cylinder is = %f litres\n',V2*10^3);
+
+ // (c)
+ CP = 2*n/(n-1)*P1*v1*((P2/P1)^((n-1)/n)-1);// cycle power, [MW]
+ mprintf('\n (c) The cycle power is = %f MW\n',CP*10^3);
+
+ // there is calculation mistake in the book so answer is not matching
+
+ // End
diff --git a/2705/CH14/EX14.3/Ex14_3.sce b/2705/CH14/EX14.3/Ex14_3.sce new file mode 100755 index 000000000..7b899feb5 --- /dev/null +++ b/2705/CH14/EX14.3/Ex14_3.sce @@ -0,0 +1,59 @@ +clear;
+clc;
+disp(' Example 14.3');
+
+// aim : To determine
+// (a) the intermediate pressures
+// (b) the effective swept volume of the LP cylinder
+// (c) the temperature and the volume of air delivered per stroke at 15 bar
+// (d) the work done per kilogram of air
+
+// given values
+d = 450*10^-3;// bore , [m]
+L = 300*10^-3;// stroke, [m]
+cl = .05;// clearence
+P1 = 1; // intake pressure, [bar]
+T1 = 273+18;// intake temperature, [K]
+P4 = 15;// final delivery pressure, [bar]
+n = 1.3;// compression and expansion index
+R = .29;// gas constant, [kJ/kg K]
+
+// solution
+// (a)
+k=(P4/P1)^(1/3);
+// hence
+P2 = k*P1;// intermediare pressure, [bar]
+P3 = k*P2;// intermediate pressure, [bar]
+
+mprintf('\n (a) The intermediate pressure is P2 = %f bar\n',P2);
+mprintf('\n The intermediate pressure is P3= %f bar\n',P3);
+
+// (b)
+SV = %pi*d^2/4*L;// swept volume of LP cylinder, [m^3]
+// hence
+V7 = cl*SV;// volume, [m^3]
+V1 = SV+V7;// volume, [m^3]
+// also
+P7 = P2;
+P8 = P1;
+V8 = V7*(P7/P8)^(1/n);// volume, [m^3]
+ESV = V1-V8;// effective swept volume of LP cylinder, [m^3]
+
+mprintf('\n (b) The effective swept volume of the LP cylinder is = %f litres\n',ESV*10^3);
+
+// (c)
+T9 = T1;
+P9 = P3;
+T4 = T9*(P4/P9)^((n-1)/n);// delivery temperature, [K]
+// now using P4*(V4-V5)/T4=P1*(V1-V8)/T1
+V4_minus_V5 = P1*T4*(V1-V8)/(P4*T1);// delivery volume, [m^3]
+
+mprintf('\n (c) The delivery temperature is = %f C\n',T4-273);
+mprintf('\n The delivery volume is = %f litres\n',V4_minus_V5*10^3);
+
+// (d)
+
+W = 3*n*R*T1*((P2/P1)^((n-1)/n)-1)/(n-1);// work done/kg ,[kJ]
+mprintf('\n (d) The work done per kilogram of air is = %f kJ\n',W);
+
+// End
diff --git a/2705/CH14/EX14.4/Ex14_4.sce b/2705/CH14/EX14.4/Ex14_4.sce new file mode 100755 index 000000000..8cfa8e686 --- /dev/null +++ b/2705/CH14/EX14.4/Ex14_4.sce @@ -0,0 +1,38 @@ +clear;
+clc;
+disp(' Example 14.4');
+
+// aim : To determine
+// (a) the final pressure and temperature
+// (b) the energy required to drive the compressor
+
+// given values
+rv = 5;// pressure compression ratio
+m_dot = 10;// air flow rate, [kg/s]
+P1 = 100;// initial pressure, [kN/m^2]
+T1 = 273+20;// initial temperature, [K]
+n_com = .85;// isentropic efficiency of compressor
+Gama = 1.4;// heat capacity ratio
+cp = 1.005;// specific heat capacity, [kJ/kg K]
+
+// solution
+// (a)
+T2_prim = T1*(rv)^((Gama-1)/Gama);// temperature after compression, [K]
+// using isentropic efficiency=(T2_prim-T1)/(T2-T1)
+T2 = T1+(T2_prim-T1)/n_com;// final temperature, [K]
+P2 = rv*P1;// final pressure, [kN/m^2]
+mprintf('\n (a) The final temperature is = %f C\n',T2-273);
+mprintf('\n (b) The final pressure is = %f kN/m^2\n',P2);
+
+// (b)
+E = m_dot*cp*(T1-T2);// energy required, [kW]
+mprintf('\n (b) The energy required to drive the compressor is = %f kW',E);
+if(E<0)
+ disp('The negative sign indicates energy input');
+else
+ disp('The positive sign indicates energy output');
+end
+
+ // End
+
+
diff --git a/2705/CH14/EX14.5/Ex14_5.sce b/2705/CH14/EX14.5/Ex14_5.sce new file mode 100755 index 000000000..c9d23cd92 --- /dev/null +++ b/2705/CH14/EX14.5/Ex14_5.sce @@ -0,0 +1,28 @@ +clear;
+clc;
+disp(' Example 14.5');
+
+// aim : To determine
+// the power absorbed in driving the compressor
+
+// given values
+FC = .68;// fuel consumption rate, [kg/min]
+P1 = 93;// initial pressure, [kN/m^2]
+P2 = 200;// final pressure, [kN/m^2]
+T1 = 273+15;// initial temperature, [K]
+d = 1.3;// density of mixture, [kg/m^3]
+n_com = .82;// isentropic efficiency of compressor
+Gama = 1.38;// heat capacity ratio
+
+// solution
+R = P1/(d*T1);// gas constant, [kJ/kg K]
+// for mixture
+cp = Gama*R/(Gama-1);// heat capacity, [kJ/kg K]
+T2_prim = T1*(P2/P1)^((Gama-1)/Gama);// temperature after compression, [K]
+// using isentropic efficiency=(T2_prim-T1)/(T2-T1)
+T2 = T1+(T2_prim-T1)/n_com;// final temperature, [K]
+m_dot = FC*15/60;// given condition, [kg/s]
+P = m_dot*cp*(T2-T1);// power absorbed by compressor, [kW]
+mprintf('\n The power absorbed by compressor is = %f kW\n',P);
+
+// End
diff --git a/2705/CH14/EX14.6/Ex14_6.sce b/2705/CH14/EX14.6/Ex14_6.sce new file mode 100755 index 000000000..7e971e4b6 --- /dev/null +++ b/2705/CH14/EX14.6/Ex14_6.sce @@ -0,0 +1,21 @@ +clear;
+clc;
+disp(' Example 14.6');
+
+// aim : To determine
+// the power required to drive the blower
+
+// given values
+m_dot = 1;// air capacity, [kg/s]
+rp = 2;// pressure ratio
+P1 = 1*10^5;// intake pressure, [N/m^2]
+T1 = 273+70;// intake temperature, [K]
+R = .29;// gas constant, [kJ/kg k]
+
+// solution
+V1_dot = m_dot*R*T1/P1*10^3;// [m^3/s]
+P2 = rp*P1;// final pressure, [n/m^2]
+P = V1_dot*(P2-P1);// power required, [W]
+mprintf('\n The power required to drive the blower is = %f kW\n',P*10^-3);
+
+// End
diff --git a/2705/CH14/EX14.7/Ex14_7.sce b/2705/CH14/EX14.7/Ex14_7.sce new file mode 100755 index 000000000..a367f2e9e --- /dev/null +++ b/2705/CH14/EX14.7/Ex14_7.sce @@ -0,0 +1,25 @@ +clear;
+clc;
+disp(' Example 14.7');
+
+// aim : To determine
+// the power required to drive the vane pump
+
+// given values
+m_dot = 1;// air capacity, [kg/s]
+rp = 2;// pressure ratio
+P1 = 1*10^5;// intake pressure, [N/m^2]
+T1 = 273+70;// intake temperature, [K]
+Gama = 1.4;// heat capacity ratio
+rv = .7;// volume ratio
+
+// solution
+V1 = .995;// intake pressure(as given previous question),[m^3/s]
+// using P1*V1^Gama=P2*V2^Gama, so
+P2 = P1*(1/rv)^Gama;// pressure, [N/m^2]
+V2 = rv*V1;// volume,[m^3/s]
+P3 = rp*P1;// final pressure, [N/m^2]
+P = Gama/(Gama-1)*P1*V1*((P2/P1)^((Gama-1)/Gama)-1)+V2*(P3-P2);// power required,[W]
+mprintf('\n The power required to drive the vane pump is = %f kW\n',P*10^-3);
+
+// End
diff --git a/2705/CH14/EX14.8/Ex14_8.sce b/2705/CH14/EX14.8/Ex14_8.sce new file mode 100755 index 000000000..e851d6a3b --- /dev/null +++ b/2705/CH14/EX14.8/Ex14_8.sce @@ -0,0 +1,36 @@ +clear;
+clc;
+disp(' Example 14.8');
+
+// aim : To determine
+// the total temperature and pressure of the mixture
+
+// given values
+rp = 2.5;// static pressure ratio
+FC = .04;// fuel consumption rate, [kg/min]
+P1 = 60;// inilet pressure, [kN/m^2]
+T1 = 273+5;// inilet temperature, [K]
+n_com = .84;// isentropic efficiency of compressor
+Gama = 1.39;// heat capacity ratio
+C2 = 120;//exit velocity from compressor, [m/s]
+rm = 13;// air-fuel ratio
+cp = 1.005;// heat capacity ratio
+
+// solution
+P2 = rp*P1;// given condition, [kN/m^2]
+T2_prim = T1*(P2/P1)^((Gama-1)/Gama);// temperature after compression, [K]
+// using isentropic efficiency=(T2_prim-T1)/(T2-T1)
+T2 = T1+(T2_prim-T1)/n_com;// final temperature, [K]
+m_dot = FC*(rm+1);// mass of air-fuel mixture, [kg/s]
+P = m_dot*cp*(T2-T1);// power to drive compressor, [kW]
+mprintf('\n The power required to drive compressor is = %f kW\n',P);
+
+Tt2 = T2+C2^2/(2*cp*10^3);// total temperature,[K]
+Pt2 = P2*(Tt2/T2)^(Gama/(Gama-1));// total pressure, [kN/m^2]
+mprintf('\n The temperature in the engine is = %f C\n',Tt2-273);
+mprintf('\n The pressure in the engine cylinder is = %f kN/m^2\n',Pt2);
+
+// There is calculation mistake in the book
+
+
+// End
diff --git a/2705/CH15/EX15.1/Ex15_1.sce b/2705/CH15/EX15.1/Ex15_1.sce new file mode 100755 index 000000000..153a3eea6 --- /dev/null +++ b/2705/CH15/EX15.1/Ex15_1.sce @@ -0,0 +1,17 @@ +clear;
+clc;
+disp('Example 15.1');
+
+// aim : To determine
+// the thermal efficiency of the cycle
+
+// given values
+T1 = 273+400;// temperature limit, [K]
+T3 = 273+70;// temperature limit, [K]
+
+// solution
+// using equation [15] of section 15.3
+n_the = (T1-T3)/T1*100;// thermal efficiency
+mprintf('\n The thermal efficiency of the cycle is = %f percent\n',n_the);
+
+// End
diff --git a/2705/CH15/EX15.10/Ex15_10.sce b/2705/CH15/EX15.10/Ex15_10.sce new file mode 100755 index 000000000..5748bff66 --- /dev/null +++ b/2705/CH15/EX15.10/Ex15_10.sce @@ -0,0 +1,32 @@ +clear;
+clc;
+disp('Example 10');
+
+// aim : To determine
+// (a) the maximum temperature attained during the cycle
+// (b) the thermal efficiency of the cycle
+
+// given value
+rva =7.5;// volume ratio of adiabatic expansion
+rvc =15;// volume ratio of compression
+P1 = 98;// initial pressure, [kn/m^2]
+T1 = 273+44;// initial temperature, [K]
+P4 = 258;// pressure at the end of the adiabatic expansion, [kN/m^2]
+Gama = 1.4;// heat capacity ratio
+
+// solution
+// by seeing diagram
+// for process 4-1, P4/T4=P1/T1
+T4 = T1*(P4/P1);// [K]
+// for process 3-4
+T3 = T4*(rva)^(Gama-1);
+mprintf('\n (a) The maximum temperature during the cycle is = %f C\n',T3-273);
+
+// (b)
+
+// for process 1-2,
+T2 = T1*(rvc)^(Gama-1);// [K]
+n_the = 1-(T4-T1)/((Gama)*(T3-T2));// thermal efficiency
+mprintf('\n (b) The thermal efficiency of the cycle is = %f percent\n',n_the*100);
+
+// End
diff --git a/2705/CH15/EX15.11/Ex15_11.sce b/2705/CH15/EX15.11/Ex15_11.sce new file mode 100755 index 000000000..9045f1cd3 --- /dev/null +++ b/2705/CH15/EX15.11/Ex15_11.sce @@ -0,0 +1,37 @@ +clear;
+clc;
+disp('Example 15.11');
+
+// aim : To determine
+// (a) the thermal efficiency of the cycle
+// (b) the indicared power of the cycle
+
+// given values
+// taking basis one second
+rv = 11;// volume ratio
+P1 = 96;// initial pressure , [kN/m^2]
+T1 = 273+18;// initial temperature, [K]
+Gama = 1.4;// heat capacity ratio
+
+// solution
+// taking reference Fig. 15.24
+// (a)
+Beta = 2;// ratio of V3 and V2
+TE = 1-(Beta^(Gama)-1)/((rv^(Gama-1))*Gama*(Beta-1));// thermal efficiency
+mprintf('\n (a) the thermal efficiency of the cycle is = %f percent\n ',TE*100);
+
+// (b)
+// let V1-V2=.05, so
+V2 = .05*.1;// [m^3]
+// from this
+V1 = rv*V2;// [m^3]
+V3 = Beta*V2;// [m^3]
+V4 = V1;// [m^3]
+P2 = P1*(V1/V2)^(Gama);// [kN/m^2]
+P3 = P2;// [kn/m^2]
+P4=P3*(V3/V4)^(Gama);// [kN/m^2]
+// indicated power
+W = P2*(V3-V2)+((P3*V3-P4*V4)-(P2*V2-P1*V1))/(Gama-1);// indicated power, [kW]
+mprintf('\n (c) The indicated power of the cycle is = %f kW\n',W);
+
+// End
diff --git a/2705/CH15/EX15.12/Ex15_12.sce b/2705/CH15/EX15.12/Ex15_12.sce new file mode 100755 index 000000000..43bddcdf8 --- /dev/null +++ b/2705/CH15/EX15.12/Ex15_12.sce @@ -0,0 +1,48 @@ +clear;
+clc;
+disp('Example 15.12');
+
+// aim : To determine
+// (a) the pressure and temperature at the end of compression
+// (b) the pressure and temperature at the end of the constant volume process
+// (c) the temperature at the end of constant pressure process
+
+// given values
+P1 = 103;// initial pressure, [kN/m^2]
+T1 = 273+22;// initial temperature, [K]
+rv = 16;// volume ratio of the compression
+Q = 244;//heat added, [kJ/kg]
+Gama = 1.4;// heat capacity ratio
+cv = .717;// heat capacity, [kJ/kg k]
+
+// solution
+// taking reference as Fig.15.26
+// (a)
+// for compression
+// rv = V1/V2
+P2 = P1*(rv)^Gama;// pressure at end of compression, [kN/m^2]
+T2 = T1*(rv)^(Gama-1);// temperature at end of compression, [K]
+mprintf('\n (a) The pressure at the end of compression is = %f MN/m^2\n',P2*10^-3);
+mprintf('\n The temperature at the end of compression is = %f C\n',T2-273);
+
+// (b)
+// for constant volume process,
+// Q = cv*(T3-T2), so
+T3 = T2+Q/cv;// temperature at the end of constant volume, [K]
+
+// so for constant volume, P/T=constant, hence
+P3 = P2*(T3/T2);// pressure at the end of constant volume process, [kN/m^2]
+mprintf('\n (b) The pressure at the end of constant volume process is = %f MN/m^2\n ',P3*10^-3);
+mprintf('\n The temperature at the end of constant volume process is = %f C\n',T3-273);
+
+// (c)
+S = rv-1;// stroke
+// assuming
+V3 = 1;// [volume]
+//so
+V4 = V3+S*.03;// [volume]
+// also for constant process V/T=constant, hence
+T4 = T3*(V4/V3);// temperature at the end of constant presure process, [k]
+mprintf('\n (c) The temperature at the end of constant pressure process is = %f C\n',T4-273);
+
+// End
diff --git a/2705/CH15/EX15.13/Ex15_13.sce b/2705/CH15/EX15.13/Ex15_13.sce new file mode 100755 index 000000000..50608fe00 --- /dev/null +++ b/2705/CH15/EX15.13/Ex15_13.sce @@ -0,0 +1,79 @@ +clear;
+clc;
+disp('Example 15.13');
+
+// aim : To determine
+// (a) the pressure, volume and temperature at cycle process change points
+// (b) the net work done
+// (c) the thermal efficiency
+// (d) the heat received
+// (e) the work ratio
+// (f) the mean effective pressure
+// (g) the carnot efficiency
+
+
+// given values
+rv = 15;// volume ratio
+P1 = 97*10^-3;// initial pressure , [MN/m^2]
+V1 = .084;// initial volume, [m^3]
+T1 = 273+28;// initial temperature, [K]
+T4 = 273+1320;// maximum temperature, [K]
+P3 = 6.2;// maximum pressure, [MN/m^2]
+cp = 1.005;// specific heat capacity at constant pressure, [kJ/kg K]
+cv = .717;// specific heat capacity at constant volume, [kJ/kg K]
+
+// solution
+// taking reference Fig. 15.27
+// (a)
+R = cp-cv;// gas constant, [kJ/kg K]
+Gama = cp/cv;// heat capacity ratio
+// for process 1-2
+V2 = V1/rv;// volume at stage2, [m^3]
+// using PV^(Gama)=constant for process 1-2
+P2 = P1*(V1/V2)^(Gama);// pressure at stage2,. [MN/m^2]
+T2 = T1*(V1/V2)^(Gama-1);// temperature at stage 2, [K]
+
+// for process 2-3
+// since volumee is constant in process 2-3 , so using P/T=constant, so
+T3 = T2*(P3/P2);// volume at stage 3, [K]
+V3 = V2;// volume at stage 3, [MN/m^2]
+
+// for process 3-4
+P4 = P3;// pressure at stage 4, [m^3]
+// since in stage 3-4 P is constant, so V/T=constant,
+V4 = V3*(T4/T3);// temperature at stage 4,[K]
+
+// for process 4-5
+V5 = V1;// volume at stage 5, [m^3]
+P5 = P4*(V4/V5)^(Gama);// pressure at stage5,. [MN/m^2]
+T5 = T4*(V4/V5)^(Gama-1);// temperature at stage 5, [K]
+
+mprintf('\n (a) P1 = %f kN/m^2, V1 = %f m^3, t1 = %f C,\n P2 = %f MN/m^2, V2 = %f m^3, t2 = %f C,\n P3 = %f MN/m^2, V3 = %f m^3, t3 = %f C,\n P4 = %f MN/m^2, V4 = %f m^3, t4 = %f C,\n P5 = %fkN/m^2, V5 = %fm^3, t5 = %fC\n',P1*10^3,V1,T1-273,P2,V2,T2-273,P3,V3,T3-273,P4,V4,T4-273,P5*10^3,V5,T5-273);
+
+
+// (b)
+W = (P3*(V4-V3)+((P4*V4-P5*V5)-(P2*V2-P1*V1))/(Gama-1))*10^3;// work done, [kJ]
+mprintf('\n (b) The net work done is = %f kJ\n',W);
+
+// (c)
+TE = 1-(T5-T1)/((T3-T2)+Gama*(T4-T3));// thermal efficiency
+mprintf('\n (c) The thermal efficiency is = %f percent\n',TE*100);
+
+// (d)
+Q = W/TE;// heat received, [kJ]
+mprintf('\n (d) The heat received is = %f kJ\n',Q);
+
+// (e)
+PW = P3*(V4-V3)+(P4*V4-P5*V5)/(Gama-1)
+WR = W*10^-3/PW;// work ratio
+mprintf('\n (f) The work ratio is = %f\n',WR);
+
+// (e)
+Pm = W/(V1-V2);// mean effective pressure, [kN/m^2]
+mprintf('\n (e) The mean effective pressure is = %f kN/m^2\n',Pm);
+
+// (f)
+CE = (T4-T1)/T4;// carnot efficiency
+mprintf('\n (f) The carnot efficiency is = %f percent\n',CE*100);
+
+// End
diff --git a/2705/CH15/EX15.14/Ex15_14.sce b/2705/CH15/EX15.14/Ex15_14.sce new file mode 100755 index 000000000..ebf067b5b --- /dev/null +++ b/2705/CH15/EX15.14/Ex15_14.sce @@ -0,0 +1,77 @@ +clear;
+clc;
+disp('Example 15.14');
+
+// aim : To determine
+// (a) the thermal efficiency
+// (b) the heat received
+// (c) the heat rejected
+// (d) the net work
+// (e) the work ratio
+// (f) the mean effective pressure
+// (g) the carnot efficiency
+
+
+// given values
+P1 = 101;// initial pressure , [kN/m^2]
+V1 = 14*10^-3;// initial volume, [m^3]
+T1 = 273+15;// initial temperature, [K]
+P3 = 1850;// maximum pressure, [kN/m^2]
+V2 = 2.8*10^-3;// compressed volume, [m^3]
+Gama = 1.4;// heat capacity
+R = .29;// gas constant, [kJ/kg k]
+
+// solution
+// taking reference Fig. 15.29
+// (a)
+// for process 1-2
+// using PV^(Gama)=constant for process 1-2
+P2 = P1*(V1/V2)^(Gama);// pressure at stage2,. [MN/m^2]
+T2 = T1*(V1/V2)^(Gama-1);// temperature at stage 2, [K]
+
+// for process 2-3
+// since volumee is constant in process 2-3 , so using P/T=constant, so
+T3 = T2*(P3/P2);// volume at stage 3, [K]
+
+// for process 3-4
+P4 = P1;
+T4 = T3*(P4/P3)^((Gama-1)/Gama);// temperature
+
+TE = 1-Gama*(T4-T1)/(T3-T2);// thermal efficiency
+mprintf('\n (a) The thermal efficiency is = %f percent\n',TE*100);
+
+// (b)
+cv = R/(Gama-1);// heat capacity at copnstant volume, [kJ/kg k]
+m = P1*V1/(R*T1);// mass of gas, [kg]
+Q1 = m*cv*(T3-T2);// heat received, [kJ/cycle]
+mprintf('\n (b) The heat received is = %f kJ/cycle\n',Q1);
+
+// (c)
+cp = Gama*cv;// heat capacity at constant at constant pressure, [kJ/kg K]
+Q2 = m*cp*(T4-T1);// heat rejected, [kJ/cycle]
+mprintf('\n (c) The heat rejected is = %f kJ/cycle\n',Q2);
+
+// (d)
+W = Q1-Q2;// net work , [kJ/cycle]
+mprintf('\n (d) The net work is = %f kJ/cycle\n',W);
+
+// (e)
+// pressure is constant for process 1-4, so V/T=constant
+V4 = V1*(T4/T1);// volume, [m^3]
+V3 = V2;// for process 2-3
+P4 = P1;// for process 1-4
+PW = (P3*V3-P1*V1)/(Gama-1);// positive work done, [kJ/cycle]
+WR = W/PW;// work ratio
+mprintf('\n (e) The work ratio is = %f\n',WR);
+
+// (f)
+Pm = W/(V4-V2);// mean effective pressure, [kN/m^2]
+mprintf('\n (f) The mean effefctive pressure is = %f kN/m^2\n',Pm);
+
+// (g)
+CE = (T3-T1)/T3;// carnot efficiency
+mprintf('\n (g) The carnot efficiency is = %f percent\n',CE*100);
+
+// there is minor variation in answer reported in the book
+
+// End
diff --git a/2705/CH15/EX15.15/Ex15_15.sce b/2705/CH15/EX15.15/Ex15_15.sce new file mode 100755 index 000000000..d6b24e902 --- /dev/null +++ b/2705/CH15/EX15.15/Ex15_15.sce @@ -0,0 +1,41 @@ +clear;
+clc;
+disp('Example 15.15');
+
+// aim : To determine
+// (a) the net work done
+// (b) the ideal thermal efficiency
+// (c) the thermal efficiency if the process of generation is not included
+
+// given values
+P1 = 110;// initial pressure, [kN/m^2)
+T1 = 273+30;// initial temperature, [K]
+V1 = .05;// initial volume, [m^3]
+V2 = .005;// volume, [m^3]
+T3 = 273+700;// temperature, [m^3]
+R = .289;// gas constant, [kJ/kg K]
+cv = .718;// heat capacity, [kJ/kg K]
+
+// solution
+// (a)
+m = P1*V1/(R*T1);// mass , [kg]
+W = m*R*(T3-T1)*log(V1/V2);// work done, [kJ]
+mprintf('\n (a) The net work done is = %f kJ\n',W);
+
+// (b)
+n_the = (T3-T1)/T3;// ideal thermal efficiency
+mprintf('\n (b) The ideal thermal efficiency is = %f percent\n',n_the*100);
+
+// (c)
+V4 = V1;
+V3 = V2;
+T4 = T3;
+T2 = T1;
+
+Q_rej = m*cv*(T4-T1)+m*R*T1*log(V1/V2);// heat rejected
+Q_rec = m*cv*(T3-T2)+m*R*T3*log(V4/V3);// heat received
+
+n_th = (1-Q_rej/Q_rec);// thermal efficiency
+mprintf('\n (c) the thermal efficiency if the process of regeneration is not included is = %f percent\n',n_th*100);
+
+// End
diff --git a/2705/CH15/EX15.16/Ex15_16.sce b/2705/CH15/EX15.16/Ex15_16.sce new file mode 100755 index 000000000..5417fa898 --- /dev/null +++ b/2705/CH15/EX15.16/Ex15_16.sce @@ -0,0 +1,48 @@ +clear;
+clc;
+disp('Example 15.16');
+
+// aim : To determine
+// (a) the maximum temperature
+// (b) the net work done
+// (c) the ideal thermal efficiency
+// (d) the thermal efficiency if the process of regeneration is not included
+
+// given values
+P1 = 100;// initial pressure, [kN/m^2)
+T1 = 273+20;// initial temperature, [K]
+V1 = .08;// initial volume, [m^3]
+rv = 5;// volume ratio
+R = .287;// gas constant, [kJ/kg K]
+cp = 1.006;// heat capacity, [kJ/kg K]
+V3_by_V2 = 2;
+
+// solution
+// (a)
+// using Fig.15.33
+// process 1-2 is isothermal
+T2 = T1;
+// since process 2-3 isisobaric, so V/T=constant
+T3 = T2*(V3_by_V2);// maximumtemperature, [K]
+mprintf('\n (a) The maximum temperature is = %f C\n',T3-273);
+
+// (b)
+m = P1*V1/(R*T1);// mass , [kg]
+W = m*R*(T3-T1)*log(rv);// work done, [kJ]
+mprintf('\n (b) The net work done is = %f kJ\n',W);
+
+// (c)
+TE = (T3-T1)/T3;// ideal thermal efficiency
+mprintf('\n (c) The ideal thermal efficiency is = %f percent\n',TE*100);
+
+// (d)
+T4 = T3;
+T2 = T1;
+
+Q_rej = m*cp*(T4-T1)+m*R*T1*log(rv);// heat rejected
+Q_rec = m*cp*(T3-T2)+m*R*T3*log(rv);// heat received
+
+n_th = (1-Q_rej/Q_rec);// thermal efficiency
+mprintf('\n (d) the thermal efficiency if the process of regeneration is not included is = %f percent\n',n_th*100);
+
+// End
diff --git a/2705/CH15/EX15.17/Ex15_17.sce b/2705/CH15/EX15.17/Ex15_17.sce new file mode 100755 index 000000000..5182839fe --- /dev/null +++ b/2705/CH15/EX15.17/Ex15_17.sce @@ -0,0 +1,36 @@ +clear;
+clc;
+disp('Example 15.17');
+
+// aim : To determine
+// (a) the net work done
+// (b) thethermal efficiency
+
+// given values
+m = 1;// mass of air, [kg]
+T1 = 273+230;// initial temperature, [K]
+P1 = 3450;// initial pressure, [kN/m^2]
+P2 = 2000;// pressure, [kN/m^2]
+P3 = 140;// pressure, [kN/m^2]
+P4 = P3;
+Gama = 1.4; // heat capacity ratio
+cp = 1.006;// heat capacity, [kJ/kg k]
+
+// solution
+T2 =T1;// isothermal process 1-2
+// process 2-3 and 1-4 are adiabatic so
+T3 = T2*(P3/P2)^((Gama-1)/Gama);// temperature, [K]
+T4 = T1*(P4/P1)^((Gama-1)/Gama);// [K]
+R = cp*(Gama-1)/Gama;// gas constant, [kJ/kg K]
+Q1 = m*R*T1*log(P1/P2);// heat received, [kJ]
+Q2 = m*cp*(T3-T4);// heat rejected
+
+//hence
+W = Q1-Q2;// work done
+mprintf('\n (a) The net work done is = %f kJ\n',W);
+
+// (b)
+TE = 1-Q2/Q1;// thermal efficiency
+mprintf('\n (b) The thermal efficiency is = %f percent\n',TE*100);
+
+// End
diff --git a/2705/CH15/EX15.18/Ex15_18.sce b/2705/CH15/EX15.18/Ex15_18.sce new file mode 100755 index 000000000..2932ac9d0 --- /dev/null +++ b/2705/CH15/EX15.18/Ex15_18.sce @@ -0,0 +1,22 @@ +clear;
+clc;
+disp('Example 15.18');
+
+// aim : To determine
+// thermal eficiency
+// carnot efficiency
+
+// given values
+rv = 5;// volume ratio
+Gama = 1.4;// heat capacity ratio
+
+// solution
+// under given condition
+
+TE = 1-(1/Gama*(2-1/rv^(Gama-1)))/(1+2*((Gama-1)/Gama)*log(rv/2));// thermal efficiency
+mprintf('\n The thermal efficiency is = %f percent\n',TE*100);
+
+CE = 1-1/(2*rv^(Gama-1));// carnot efficiency
+mprintf('\n The carnot efficiency is = %f \n',CE*100);
+
+// End
diff --git a/2705/CH15/EX15.2/Ex15_2.sce b/2705/CH15/EX15.2/Ex15_2.sce new file mode 100755 index 000000000..2d6440345 --- /dev/null +++ b/2705/CH15/EX15.2/Ex15_2.sce @@ -0,0 +1,29 @@ +clear;
+clc;
+disp('Example 15.2');
+
+// aim : To determine
+// (a) the volume ratios of the isothermal and adiabatic processes
+// (b) the thermal efficiency of the cycle
+
+// given values
+T1 = 273+260;// temperature, [K]
+T3 = 273+21;// temperature, [K]
+er = 15;// expansion ratio
+Gama = 1.4;// heat capacity ratio
+
+// solution
+// (a)
+T2 = T1;
+T4 = T3;
+// for adiabatic process
+rva = (T1/T4)^(1/(Gama-1));// volume ratio of adiabatic
+rvi = er/rva;// volume ratio of isothermal
+mprintf('\n (a) The volume ratio of the adiabatic process is = %f\n',rva);
+mprintf('\n The volume ratio of the isothermal process is = %f\n',rvi);
+
+// (b)
+n_the = (T1-T4)/T1*100;// thermal efficiency
+mprintf('\n (b) The thermal efficiency of the cycle is = %f percent\n',n_the);
+
+// End
diff --git a/2705/CH15/EX15.3/Ex15_3.sce b/2705/CH15/EX15.3/Ex15_3.sce new file mode 100755 index 000000000..8cab979fa --- /dev/null +++ b/2705/CH15/EX15.3/Ex15_3.sce @@ -0,0 +1,69 @@ +clear;
+clc;
+disp('Example 15.3');
+
+// aim : To determine
+// (a) the pressure, volume and temperature at each corner of the cycle
+// (b) the thermal efficiency of the cycle
+// (c) the work done per cycle
+// (d) the work ratio
+
+// given values
+m = 1;// mass of air, [kg]
+P1 = 1730;// initial pressure of carnot engine, [kN/m^2]
+T1 = 273+300;// initial temperature, [K]
+R = .29;// [kJ/kg K]
+Gama = 1.4;// heat capacity ratio
+
+// solution
+// taking reference Fig. 15.15
+// (a)
+// for the isothermal process 1-2
+// using ideal gas law
+V1 = m*R*T1/P1;// initial volume, [m^3]
+T2 = T1;
+V2 = 3*V1;// given condition
+// for isothermal process, P1*V1=P2*V2, so
+P2 = P1*(V1/V2);// [MN/m^2]
+// for the adiabatic process 2-3
+V3 = 6*V1;// given condition
+T3 = T2*(V2/V3)^(Gama-1);
+// also for adiabatic process, P2*V2^Gama=P3*V3^Gama, so
+P3 = P2*(V2/V3)^Gama;
+// for the isothermal process 3-4
+T4 = T3;
+// for both adiabatic processes, the temperataure ratio is same,
+// T1/T4 = T2/T3=(V4/V1)^(Gama-1)=(V3/V2)^(Gama-1), so
+V4 = 2*V1;
+// for isothermal process, 3-4, P3*V3=P4*V4, so
+P4 = P3*(V3/V4);
+disp('(a) At line 1');
+mprintf('\n V1 = %f m^3, t1 = %f C, P1 = %f kN/m^2\n',V1,T1-273,P1);
+
+disp('At line 2');
+mprintf('\n V2 = %f m^3, t2 = %f C, P2 = %f kN/m^2\n',V2,T2-273,P2);
+
+disp('At line 3');
+mprintf('\n V3 = %f m^3, t3 = %f C, P3 = %f kN/m^2\n',V3,T3-273,P3);
+
+
+disp('At line 4');
+mprintf('\n V4 = %f m^3, t4 = %f C, P4 = %f kN/m^2\n',V4,T4-273,P4);
+
+
+// (b)
+n_the = (T1-T3)/T1;// thermal efficiency
+mprintf('\n (b) The thermal efficiency of the cycle is = %f percent\n',n_the*100);
+
+// (c)
+W = m*R*T1*log(V2/V1)*n_the;// work done, [J]
+mprintf('\n (c) The work done per cycle is = %f kJ\n',W);
+
+// (d)
+wr = (T1-T3)*log(V2/V1)/(T1*log(V2/V1)+(T1-T3)/(Gama-1));// work ratio
+mprintf('\n (d) The work ratio is = %f\n',wr);
+
+// there is calculation mistake in the book so answer is not matching
+
+// End
+
diff --git a/2705/CH15/EX15.4/Ex15_4.sce b/2705/CH15/EX15.4/Ex15_4.sce new file mode 100755 index 000000000..e13c274f1 --- /dev/null +++ b/2705/CH15/EX15.4/Ex15_4.sce @@ -0,0 +1,72 @@ +clear;
+clc;
+disp('Example 15.4');
+
+// aim : To determine
+// (a) the pressure, volume and temperature at cycle state points
+// (b) the heat received
+// (c) the work done
+// (d) the thermal efficiency
+// (e) the carnot efficiency
+// (f) the work ration
+// (g) the mean effective pressure
+
+// given values
+ro = 8;// overall volume ratio;
+rv = 6;// volume ratio of adiabatic compression
+P1 = 100;// initial pressure , [kN/m^2]
+V1 = .084;// initial volume, [m^3]
+T1 = 273+28;// initial temperature, [K]
+Gama = 1.4;// heat capacity ratio
+cp = 1.006;// specific heat capacity, [kJ/kg K]
+
+// solution
+// taking reference Fig. 15.18
+// (a)
+V2 = V1/rv;// volume at stage2, [m^3]
+V4 = ro*V2;// volume at stage 4;[m^3]
+// using PV^(Gama)=constant for process 1-2
+P2 = P1*(V1/V2)^(Gama);// pressure at stage2,. [kN/m^2]
+T2 = T1*(V1/V2)^(Gama-1);// [K]
+
+P3 = P2;// pressure at stage 3, [kN/m^2]
+V3 = V4/rv;// volume at stage 3, [m^3]
+// since pressure is constant in process 2-3 , so using V/T=constant, so
+T3 = T2*(V3/V2);// temperature at stage 3, [K]
+
+// for process 1-4
+T4 = T1*(V4/V1);// temperature at stage4, [K
+P4 = P1;// pressure at stage4, [kN/m^2]
+
+mprintf('\n (a) P1 = %f kN/m^2, V1 = %f m^3, t1 = %f C,\n P2 = %f kN/m^2, V2 = %f m^3, t2 = %f C,\n P3 = %f kN/m^2, V3 = %f m^3, t3 = %f C,\n P4 = %f kN/m^2, V4 = %f m^3, t4 = %f C\n',P1,V1,T1-273,P2,V2,T2-273,P3,V3,T3-273,P4,V4,T4-273);
+
+// (b)
+R = cp*(Gama-1)/Gama;// gas constant, [kJ/kg K]
+m = P1*V1/(R*T1);// mass of gas, [kg]
+Q = m*cp*(T3-T2);// heat received, [kJ]
+mprintf('\n (b) The heat received is = %f kJ\n',Q);
+
+// (c)
+W = P2*(V3-V2)-P1*(V4-V1)+((P3*V3-P4*V4)-(P2*V2-P1*V1))/(Gama-1);// work done, [kJ]
+mprintf('\n (c) The work done is = %f kJ\n',W);
+
+// (d)
+TE = 1-T1/T2;// thermal efficiency
+mprintf('\n (d) The thermal efficiency is = %f percent\n',TE*100);
+
+// (e)
+CE = (T3-T1)/T3;// carnot efficiency
+mprintf('\n (e) The carnot efficiency is = %f percent\n',CE*100);
+
+// (f)
+PW = P2*(V3-V2)+(P3*V3-P4*V4)/(Gama-1);// positive work done, [kj]
+WR = W/PW;// work ratio
+mprintf('\n (f) The work ratio is = %f\n',WR);
+
+// (g)
+Pm = W/(V4-V2);// mean effective pressure, [kN/m^2]
+mprintf('\n (g) The mean effective pressure is = %f kN/m^2\n',Pm);
+
+// there is minor variation in answer reported in the book
+
+// End
diff --git a/2705/CH15/EX15.5/Ex15_5.sce b/2705/CH15/EX15.5/Ex15_5.sce new file mode 100755 index 000000000..7de39d424 --- /dev/null +++ b/2705/CH15/EX15.5/Ex15_5.sce @@ -0,0 +1,28 @@ +clear;
+clc;
+disp('Example 15.5');
+
+// aim : To determine
+// (a) the actual thermal efficiency of the turbine
+// (b) the specific fuel consumption of the turbine in kg/kWh
+
+// given values
+P2_by_P1 = 8;
+n_tur = .6;// ideal turbine thermal efficiency
+c = 43*10^3;// calorific value of fuel, [kJ/kg]
+Gama = 1.4;// heat capacity ratio
+
+// solution
+// (a)
+rv = P2_by_P1;
+n_tur_ide = 1-1/(P2_by_P1)^((Gama-1)/Gama);// ideal thermal efficiency
+ate = n_tur_ide*n_tur;// actual thermal efficiency
+mprintf('\n (a) The actual thermal efficiency of the turbine is = %f percent\n',ate*100);
+
+// (b)
+ewf = c*ate;// energy to work fuel, [kJ/kg]
+kWh = 3600;// energy equivalent ,[kJ]
+sfc = kWh/ewf;// specific fuel consumption, [kg/kWh]
+mprintf('\n (b) The specific fuel consumption of the turbine is = %f kg/kWh',sfc);
+
+// End
diff --git a/2705/CH15/EX15.6/Ex15_6.sce b/2705/CH15/EX15.6/Ex15_6.sce new file mode 100755 index 000000000..d0bad01c2 --- /dev/null +++ b/2705/CH15/EX15.6/Ex15_6.sce @@ -0,0 +1,23 @@ +clear;
+clc;
+disp('Example 15.6');
+
+// aim : To determine
+// the relative efficiency of the engine
+
+// given values
+d = 80;// bore, [mm]
+l = 85;// stroke, [mm]
+V1 = .06*10^6;// clearence volume, [mm^3]
+ate = .22;// actual thermal efficiency of the engine
+Gama = 1.4;// heat capacity ratio
+
+// solution
+sv = %pi*d^2/4*l;// stroke volume, [mm^3]
+V2 = sv+V1;// [mm^3]
+rv = V2/V1;
+ite = 1-(1/rv)^(Gama-1);// ideal thermal efficiency
+re = ate/ite;// relative thermal efficiency
+mprintf('\n The relative efficiency of the engine is = %f percent\n',re*100);
+
+// End
diff --git a/2705/CH15/EX15.7/Ex15_7.sce b/2705/CH15/EX15.7/Ex15_7.sce new file mode 100755 index 000000000..0f950939f --- /dev/null +++ b/2705/CH15/EX15.7/Ex15_7.sce @@ -0,0 +1,68 @@ +clear;
+clc;
+disp('Example 15.7');
+
+// aim : To determine
+// (a) the pressure, volume and temperature at each cycle process change points
+// (b) the heat transferred to air
+// (c) the heat rejected by the air
+// (d) the ideal thermal efficiency
+// (e) the work done
+// (f) the mean effective pressure
+
+// given values
+m = 1;// mass of air, [kg]
+rv = 6;// volume ratio of adiabatic compression
+P1 = 103;// initial pressure , [kN/m^2]
+T1 = 273+100;// initial temperature, [K]
+P3 = 3450;// maximum pressure, [kN/m^2]
+Gama = 1.4;// heat capacity ratio
+R = .287;// gas constant, [kJ/kg K]
+
+// solution
+// taking reference Fig. 15.20
+// (a)
+// for point 1
+V1 = m*R*T1/P1;// initial volume, [m^3]
+
+// for point 2
+V2 = V1/rv;// volume at point 2, [m^3]
+// using PV^(Gama)=constant for process 1-2
+P2 = P1*(V1/V2)^(Gama);// pressure at point 2,. [kN/m^2]
+T2 = T1*(V1/V2)^(Gama-1);// temperature at point 2,[K]
+
+// for point 3
+V3 = V2;// volume at point 3, [m^3]
+// since volume is constant in process 2-3 , so using P/T=constant, so
+T3 = T2*(P3/P2);// temperature at stage 3, [K]
+
+// for point 4
+V4 = V1;// volume at point 4, [m^3]
+P4 = P3*(V3/V4)^Gama;// pressure at point 4, [kN/m^2]
+// again since volume is constant in process 4-1 , so using P/T=constant, so
+T4 = T1*(P4/P1);// temperature at point 4, [K]
+
+mprintf('\n (a) P1 = %f kN/m^2, V1 = %f m^3, t1 = %f C,\n P2 = %f kN/m^2, V2 = %f m^3, t2 = %f C,\n P3 = %f kN/m^2, V3 = %f m^3, t3 = %f C,\n P4 = %f kN/m^2, V4 = %f m^3, t4 = %f C\n',P1,V1,T1-273,P2,V2,T2-273,P3,V3,T3-273,P4,V4,T4-273);
+
+// (b)
+cv = R/(Gama-1);// specific heat capacity, [kJ/kg K]
+Q23 = m*cv*(T3-T2);// heat transferred, [kJ]
+mprintf('\n (b) The heat transferred to the air is = %f kJ\n',Q23);
+
+// (c)
+Q34 = m*cv*(T4-T1);// heat rejected by air, [kJ]
+mprintf('\n (c) The heat rejected by the air is = %f kJ\n',Q34);
+
+// (d)
+TE = 1-Q34/Q23;// ideal thermal efficiency
+mprintf('\n (d) The ideal thermal efficiency is = %f percent\n',TE*100);
+
+// (e)
+W = Q23-Q34;// work done ,[kJ]
+mprintf('\n (e) The work done is = %f kJ\n',W);
+
+// (f)
+Pm = W/(V1-V2);// mean effective pressure, [kN/m^2]
+mprintf('\n (f) The mean effefctive pressure is = %f kN/m^2\n',Pm);
+
+// End
diff --git a/2705/CH15/EX15.8/Ex15_8.sce b/2705/CH15/EX15.8/Ex15_8.sce new file mode 100755 index 000000000..a37208dcc --- /dev/null +++ b/2705/CH15/EX15.8/Ex15_8.sce @@ -0,0 +1,65 @@ +clear;
+clc;
+disp('Example 15.8');
+
+// aim : To determine
+// (a) the pressure, volume and temperature at cycle state points
+// (b) the thermal efficiency
+// (c) the theoretical output
+// (d) the mean effective pressure
+// (e) the carnot efficiency
+
+// given values
+rv = 9;// volume ratio
+P1 = 101;// initial pressure , [kN/m^2]
+V1 = .003;// initial volume, [m^3]
+T1 = 273+18;// initial temperature, [K]
+P3 = 4500;// maximum pressure, [kN/m^2]
+N = 3000;
+cp = 1.006;// specific heat capacity at constant pressure, [kJ/kg K]
+cv = .716;// specific heat capacity at constant volume, [kJ/kg K]
+
+// solution
+// taking reference Fig. 15.20
+// (a)
+// for process 1-2
+Gama = cp/cv;// heat capacity ratio
+R = cp-cv;// gas constant, [kJ/kg K]
+V2 = V1/rv;// volume at stage2, [m^3]
+// using PV^(Gama)=constant for process 1-2
+P2 = P1*(V1/V2)^(Gama);// pressure at stage2,. [kN/m^2]
+T2 = T1*(V1/V2)^(Gama-1);// [K]
+
+// for process 2-3
+V3 = V2;// volume at stage 3, [m^3]
+// since volume is constant in process 2-3 , so using P/T=constant, so
+T3 = T2*(P3/P2);// temperature at stage 3, [K]
+
+// for process 3-4
+V4 = V1;// volume at stage 4
+// using PV^(Gama)=constant for process 3-4
+P4 = P3*(V3/V4)^(Gama);// pressure at stage2,. [kN/m^2]
+T4 = T3*(V3/V4)^(Gama-1);// temperature at stage 4,[K]
+
+mprintf('\n (a) P1 = %f kN/m^2, V1 = %f m^3, t1 = %f C,\n P2 = %f kN/m^2, V2 = %f m^3, t2 = %f C,\n P3 = %f kN/m^2, V3 = %f m^3, t3 = %f C,\n P4 = %f kN/m^2, V4 = %f m^3, t4 = %f C\n',P1,V1,T1-273,P2,V2,T2-273,P3,V3,T3-273,P4,V4,T4-273);
+
+// (b)
+TE = 1-(T4-T1)/(T3-T2);// thermal efficiency
+mprintf('\n (b) The thermal efficiency is = %f percent\n',TE*100);
+
+// (c)
+m = P1*V1/(R*T1);// mass os gas, [kg]
+W = m*cv*((T3-T2)-(T4-T1));// work done, [kJ]
+Wt = W*N/60;// workdone per minute, [kW]
+mprintf('\n (c) The theoretical output is = %f kW\n',Wt);
+
+// (d)
+Pm = W/(V1-V2);// mean effective pressure, [kN/m^2]
+mprintf('\n (g) The mean effefctive pressure is = %f kN/m^2\n',Pm);
+
+// (e)
+CE = (T3-T1)/T3;// carnot efficiency
+mprintf('\n (e) The carnot efficiency is = %f percent\n',CE*100);
+
+
+// End
diff --git a/2705/CH15/EX15.9/Ex15_9.sce b/2705/CH15/EX15.9/Ex15_9.sce new file mode 100755 index 000000000..7482cbe06 --- /dev/null +++ b/2705/CH15/EX15.9/Ex15_9.sce @@ -0,0 +1,72 @@ +clear;
+clc;
+disp('Example 15.9');
+
+// aim : To determine
+// (a) the pressure and temperature at cycle process change points
+// (b) the work done
+// (c) the thermal efficiency
+// (d) the work ratio
+// (e) the mean effective pressure
+// (f) the carnot efficiency
+
+
+// given values
+rv = 16;// volume ratio of compression
+P1 = 90;// initial pressure , [kN/m^2]
+T1 = 273+40;// initial temperature, [K]
+T3 = 273+1400;// maximum temperature, [K]
+cp = 1.004;// specific heat capacity at constant pressure, [kJ/kg K]
+Gama = 1.4;// heat capacoty ratio
+
+// solution
+cv = cp/Gama;// specific heat capacity at constant volume, [kJ/kg K]
+R = cp-cv;// gas constant, [kJ/kg K]
+// for one kg of gas
+V1 = R*T1/P1;// initial volume, [m^3]
+// taking reference Fig. 15.22
+// (a)
+// for process 1-2
+// using PV^(Gama)=constant for process 1-2
+// also rv = V1/V2
+P2 = P1*(rv)^(Gama);// pressure at stage2,. [kN/m^2]
+T2 = T1*(rv)^(Gama-1);// temperature at stage 2, [K]
+
+// for process 2-3
+P3 = P2;// pressure at stage 3, [kN/m^2]
+V2 = V1/rv;//[m^3]
+// since pressure is constant in process 2-3 , so using V/T=constant, so
+V3 = V2*(T3/T2);// volume at stage 3, [m^3]
+
+// for process 1-4
+V4 = V1;// [m^3]
+P4 = P3*(V3/V4)^(Gama)
+// since in stage 1-4 volume is constant, so P/T=constant,
+T4 = T1*(P4/P1);// temperature at stage 4,[K]
+
+mprintf('\n (a) P1 = %f kN/m^2, t1 = %f C,\n P2 = %f kN/m^2, t2 = %f C,\n P3 = %f kN/m^2, t3 = %f C,\n P4 = %f kN/m^2, t4 = %f C\n',P1,T1-273,P2,T2-273,P3,T3-273,P4,T4-273);
+
+// (b)
+W = cp*(T3-T2)-cv*(T4-T1);// work done, [kJ]
+mprintf('\n (b) The work done is = %f kJ\n',W);
+
+// (c)
+TE = 1-(T4-T1)/((T3-T2)*Gama);// thermal efficiency
+mprintf('\n (c) The thermal efficiency is = %f percent\n',TE*100);
+
+// (d)
+PW = cp*(T3-T2)+R*(T3-T4)/(Gama-1);// positive work done
+WR = W/PW;// work ratio
+mprintf('\n (d) The work ratio is = %f\n',WR);
+
+// (e)
+Pm = W/(V1-V2);// mean effective pressure, [kN/m^2]
+mprintf('\n (e) The mean effefctive pressure is = %f kN/m^2\n',Pm);
+
+// (f)
+CE = (T3-T1)/T3;// carnot efficiency
+mprintf('\n (f) The carnot efficiency is = %f percent\n',CE*100);
+
+// value of t2 printed in the book is incorrect
+
+// End
diff --git a/2705/CH16/EX16.1/Ex16_1.sce b/2705/CH16/EX16.1/Ex16_1.sce new file mode 100755 index 000000000..b3251fa8a --- /dev/null +++ b/2705/CH16/EX16.1/Ex16_1.sce @@ -0,0 +1,45 @@ +clear;
+clc;
+disp('Example 16.1');
+
+// aim : To determine
+// (a) the net power output of the turbine plant if the turbine is coupled to the compresser
+// (b) the thermal efficiency of the plant
+// (c) the work ratio
+
+// Given values
+P1 = 100;// inlet pressure of compressor, [kN/m^2]
+T1 = 273+18;// inlet temperature, [K]
+P2 = 8*P1;// outlet pressure of compressor, [kN/m^2]
+n_com = .85;// isentropic efficiency of compressor
+T3 = 273+1000;//inlet temperature of turbine, [K]
+P3 = P2;// inlet pressure of turbine, [kN/m^2]
+P4 = 100;// outlet pressure of turbine, [kN/m^2]
+n_tur = .88;// isentropic efficiency of turbine
+m_dot = 4.5;// air mass flow rate, [kg/s]
+cp = 1.006;// [kJ/kg K]
+Gamma = 1.4;// heat capacity ratio
+
+// (a)
+// For the compressor
+T2_prime = T1*(P2/P1)^((Gamma-1)/Gamma);// [K]
+T2 = T1+(T2_prime-T1)/n_com;// exit pressure of compressor, [K]
+
+// for turbine
+T4_prime = T3*(P4/P3)^((Gamma-1)/Gamma);// [K]
+T4 = T3-(T3-T4_prime)*n_tur;// exit temperature of turbine, [K]
+
+P_output = m_dot*cp*((T3-T4)-(T2-T1));// [kW]
+mprintf('\n (a) The net power output is = %f kW\n',P_output);
+
+// (b)
+n_the = ((T3-T4)-(T2-T1))/(T3-T2)*100;// thermal efficiency
+mprintf('\n (b) The thermal efficiency of the plant is = %f percent\n',n_the);
+
+// (c)
+P_pos = m_dot*cp*(T3-T4);// Positive cycle work, [kW]
+
+W_ratio = P_output/P_pos;// work ratio
+mprintf('\n (c) The work ratio is = %f\n',W_ratio)
+
+// End
diff --git a/2705/CH16/EX16.2/Ex16_2.sce b/2705/CH16/EX16.2/Ex16_2.sce new file mode 100755 index 000000000..e76ab804c --- /dev/null +++ b/2705/CH16/EX16.2/Ex16_2.sce @@ -0,0 +1,47 @@ +clear;
+clc;
+disp('Example 16.2');
+
+// aim : To determine
+// (a) the pressure ratiowhich will give the maximum net work output
+// (b) the maximum net specific work output
+// (c) the thermal efficiency at maximum work output
+// (d) the work ratio at maximum work output
+// (e) the carnot efficiency within the cycle temperature limits
+
+// Given values
+// taking the refrence as Fig.16.35
+T3 = 273+1080;// [K]
+T1 = 273+10;// [K]
+cp = 1.007;// [kJ/kg K]
+Gamma = 1.41;// heat capacity ratio
+
+// (a)
+r_pmax = (T3/T1)^((Gamma)/(Gamma-1));// maximum pressure ratio
+// for maximum net work output
+r_p = sqrt(r_pmax);
+mprintf('\n (a) The pressure ratio which give the maximum network output is = %f\n',r_p);
+
+// (b)
+T2 = T1*(r_p)^((Gamma-1)/Gamma);// [K]
+// From equation [23]
+T4 = T2;
+W_max = cp*((T3-T4)-(T2-T1));// Maximum net specific work output, [kJ/kg]
+
+mprintf('\n (b) The maximum net specific work output is = %f kJ/kg\n',W_max);
+
+// (c)
+W = cp*(T3-T2);
+n_the = W_max/W;// thermal efficiency
+mprintf('\n (c) The thermal efficiency at maximum work output is = %f percent\n ',n_the*100);
+
+// (d)
+// From the equation [26]
+W_ratio = n_the;// Work ratio
+mprintf('\n (d) The work ratio at maximum work output is = %f\n',W_ratio);
+
+// (e)
+n_carnot = (T3-T1)/T3*100;// carnot efficiency
+mprintf('\n (e) The carnot efficiency within the cycle temperature limits is = %f percent\n',n_carnot);
+
+// End
diff --git a/2705/CH16/EX16.3/Ex16_3.sce b/2705/CH16/EX16.3/Ex16_3.sce new file mode 100755 index 000000000..de93273ac --- /dev/null +++ b/2705/CH16/EX16.3/Ex16_3.sce @@ -0,0 +1,62 @@ +clc;
+disp('Example 16.3');
+
+// aim : To determine
+// (a) the net power output of the plant
+// (b) the exhaust temperature from the heat exchanger
+// (c) the thermal efficiency of the plant
+// (d) the thermal efficiency of the plant if there were no heat exchanger
+// (e) the work ratio
+
+// Given values
+T1 = 273+15;// temperature, [K]
+P1 = 101;// pressure, [kN/m^2]
+P2 = 6*P1; // [kN/m^2]
+eff = .65;// effectiveness of the heat exchanger,
+T3 = 273+870;// temperature, [K]
+P4 = 101;// [kN/m^2]
+n_com = .85;// efficiency of compressor,
+n_tur = .80;// efficiency of turbine
+m_dot = 4;// mass flow rate, [kg/s]
+Gama = 1.4;// heat capacity ratio
+cp = 1.005;// [kJ/kg K]
+
+// solution
+// (a)
+// For compressor
+T2_prim = T1*(P2/P1)^((Gama-1)/Gama);// [K]
+
+// using n_com = (T2_prim-T1)/(T2-T1)')
+
+T2 = T1+(T2_prim-T1)/n_com
+// For turbine
+P3 = P2;
+T4_prim = T3*(P4/P3)^((Gama-1)/Gama);// [K]
+
+T4=T3-n_tur*(T3-T4_prim); // [K]
+P_out = m_dot*cp*((T3-T4)-(T2-T1));// net power output, [kW]
+mprintf('\n (a) The net power output of the plant is = %f kW\n',P_out);
+
+// (b)
+mtd = T4-T2;// maximum temperature drop for heat transfer, [K]
+atd = eff*mtd;// actual temperature, [K]
+et = T4-atd;// Exhaust temperature from heat exchanger, [K]
+t6 = et-273;// [C]
+mprintf('\n (b) The exhaust temperature from the heat exchanger is = %f C\n',t6);
+
+// (c)
+T5 = T2+atd;// [K]
+n_the = ((T3-T4)-(T2-T1))/(T3-T5)*100;// thermal effficiency
+mprintf('\n (c) The thermal efficiency of the plant is = %f percent\n',n_the);
+
+// (d)
+// with no heat exchanger
+n_the = ((T3-T4)-(T2-T1))/(T3-T2)*100;// thermal efficiency without heat exchanger
+mprintf('\n (d) The thermal efficiency of the plant if there wereno heat exchanger is = %f percent\n',n_the);
+
+// (e)
+P_pos = m_dot*cp*(T3-T4);// positive cycle work;// [kW]
+w_rat = P_out/P_pos;// work ratio
+mprintf('\n (e) The work ratio is = %f\n',w_rat)
+
+// End
diff --git a/2705/CH16/EX16.4/Ex16_4.sce b/2705/CH16/EX16.4/Ex16_4.sce new file mode 100755 index 000000000..01cd7211b --- /dev/null +++ b/2705/CH16/EX16.4/Ex16_4.sce @@ -0,0 +1,68 @@ +clear;
+clc;
+disp('Example 16.4');
+
+// aim : To determine
+// (a) the pressure and temperature as the air leaves the compressor turbine
+// (b) the power output from the free power turbine
+// (c) the thermal efficiency of the plant
+// (d) the work ratio
+// (e) the carnot efficiency within the cycle temperature limits
+
+// Given values
+T1 = 273+19;// temperature, [K]
+P1 = 100;// pressure, [kN/m^2]
+P2 = 8*P1; // [kN/m^2]
+P3 = P2;// [kN/m^2]
+T3 = 273+980;// temperature, [K]
+n_com = .85;// efficiency of rotary compressor
+P5 = 100;// [kN/m^2]
+n_cum = .88;// isentropic efficiency of combustion chamber compressor,
+n_tur = .86;// isentropic efficiency of turbine
+m_dot = 7;// mass flow rate of air, [kg/s]
+Gama = 1.4;// heat capacity ratio
+cp = 1.006;// [kJ/kg K]
+
+// solution
+// (a)
+// For compressor
+T2_prim = T1*(P2/P1)^((Gama-1)/Gama);// [K]
+
+T2 = T1+(T2_prim-T1)/n_com;// temperature, [K]
+
+// for compressor turbine
+// T3-T4 = T2-T1,because compressor turbine power=compressor power so
+T4 = T3-(T2-T1);//turbine exit temperature, [K]
+T4_prim = T3-(T3-T4)/n_cum;// [K]
+
+// For turbine
+// T4_prim = T3*(P4/P3)^((Gama-1)/Gama)
+P4 = P3*(T4_prim/T3)^(Gama/(Gama-1));// exit air pressure of air, [kN/m^2]
+
+mprintf('\n (a) The temperature as the air leaves the compressor turbine is = %f C\n',T4-273);
+mprintf('\n The pressure as the air leaves the compressor turbine is = %f kN/m^2\n',P4);
+
+// (b)
+T5_prim = T4*(P5/P4)^((Gama-1)/Gama);// [K]
+
+
+T5 = T4-n_tur*(T4-T5_prim);// temperature, [K]
+
+PO = m_dot*cp*(T4-T5);// power output
+mprintf('\n (b) The power output from the free power turbine is = %f kW\n',PO);
+
+// (c)
+
+n_the = (T4-T5)/(T3-T2)*100;// thermal effficiency
+mprintf('\n (c) The thermal efficiency of the plant is = %f percent\n',n_the);
+
+// (d)
+
+WR = (T4-T5)/(T3-T5);// work ratio
+mprintf('\n (d) The work ratio is = %f\n',WR);
+
+// (e)
+CE = (T3-T1)/T3;// carnot efficiency
+mprintf('\n (e) The carnot efficiency is = %f percent\n',CE*100);
+
+// End
diff --git a/2705/CH16/EX16.5/Ex16_5.sce b/2705/CH16/EX16.5/Ex16_5.sce new file mode 100755 index 000000000..3b2cd40b4 --- /dev/null +++ b/2705/CH16/EX16.5/Ex16_5.sce @@ -0,0 +1,51 @@ +clear;
+clc;
+disp('Example 16.5');
+
+// aim : To determine
+// (a) the pressure and temperature of the air compression
+// (b) the power developed by the gas turbine
+// (c) the temperature and pressure of the airentering the exhaust jet as it leaves the gas turbine
+
+// Given values
+T1 = 273-22.4;// temperature, [K]
+P1 = 470;// pressure, [bar]
+P2 = 30*P1; // [kN/m^2]
+P3 = P2;// [kN/m^2]
+T3 = 273+960;// temperature, [K]
+r = 1.25;// ratio of turbine power to compressor power
+n_tur = .86;// isentropic efficiency of turbine
+m_dot = 80;// mass flow rate of air, [kg/s]
+Gama = 1.41;// heat capacity ratio
+cp = 1.05;// [kJ/kg K]
+
+// solution
+// (a)
+// For compressor
+T2_prim = T1*(P2/P1)^((Gama-1)/Gama);// [K]
+// using n_tur=(T2_prim-T1)/(T2-T1)
+T2 = T1+(T2_prim-T1)/n_tur;// temperature, [K]
+
+mprintf('\n (a) The pressure of the air after compression is = %f bar\n',P2);
+
+mprintf('\n The temperature of the air after compression is = %f C\n',T2-273);
+
+// (b)
+Td = r*(T2-T1);// temperature drop in turbine, [K]
+PO = m_dot*cp*Td;// power output, [kW]
+mprintf('\n (b) The power developed by the gas turbine is = %f MW\n',PO*10^-3);
+
+// (c)
+t3 = T3-273;// [C]
+t4 = t3-Td;// temeprerature of air leaving turbine,[K]
+Tdi = Td/n_tur;// isentropic temperature drop, [K]
+T4_prim = t3-Tdi+273;// temperature, [K]
+// using T4_prim=T3*(P4/P3)^((Gama-1)/Gama)
+P4 = P3*(T4_prim/T3)^(Gama/(Gama-1));// exit air pressure of air, [kN/m^2]
+
+mprintf('\n (c) The air pressure as it leaves the gas turbine is = %f bar\n',P4);
+
+// Result in the book is not matching because they have taken pressure in mbar but in in question it is given in bar
+
+// End
+
diff --git a/2705/CH16/EX16.6/Ex16_6.sce b/2705/CH16/EX16.6/Ex16_6.sce new file mode 100755 index 000000000..5a9318ec8 --- /dev/null +++ b/2705/CH16/EX16.6/Ex16_6.sce @@ -0,0 +1,65 @@ +clc;
+disp('Example 16.6');
+
+// aim : To determine
+// (a) the mass of fuel oil used by the gas turbine
+// (b) the mass flow of steam from the boiler
+// (c) the theoretical output from the steam turbine
+// (d) the overall theoretical thermal efficiency of the plant
+
+// given values
+Po = 150;// generating plant output, [MW]
+n_the1 = .35;// thermal efficiency
+CV = 43;// calorific value of fuel, [MJ]
+me = 400;// flow rate of exhaust gas, [kg/s]
+T = 90;// boiler exit temperature, [C]
+T1 = 550;// exhaust gas temperature, [C]
+P2 = 10;// steam generation pressure, [MN/m^2]
+T2 = 450;// boiler exit temperature, [C]
+Tf = 140;// feed water temperature, [C]
+n_tur = .86;// turbine efficiency
+P3 = .5;// exhaust temperature, [MN/m^2]
+n_boi = .92;// boiler thermal efficiency
+cp = 1.1;// heat capacity, [kJ/kg]
+
+
+// solution
+// (a)
+ER = Po*3600/n_the1;// energy requirement from the fuel, [MJ/h]
+mf = ER/CV*10^-3;// fuel required, [tonne/h]
+mprintf('\n (a) The mass of fuel oil used by the gas is = %f tonne/h\n',mf);
+
+// (b)
+
+ET = me*cp*(T1-T)*3600*n_boi;// energy transferred to steam,[kJ/h]
+// from steam table
+h1 = 3244;// specific enthalpy, [kJ/kg]
+hf = 588.5;// specific enthalpy, [kJ/kg]
+ERR = h1-hf;// energy required to raise steam, [kJ/kg]
+ms = ET/ERR*10^-3;// mass flow of steam, [tonne/h]
+mprintf('\n (b) The mass flow rate of steam from the boiler is = %f tonne/h\n',ms);
+
+// again from steam table
+s1 = 6.424;// specific entropy, [kJ/kg K]
+sf2 = 1.86;// specific entropy, [kJ/kg K
+sg2 = 6.819;// specific entropy, [kJ/kg K]
+
+hf2 = 640.1;// specific enthalpy,[kJ/kg]
+hg2 = 2747.5;// specific enthalpy, [kJ/kg]
+// for ths process s1=s2=sf2+x2*(sg2-sf2)
+s2 = s1;
+// hence
+x2 = (s2-sf2)/(sg2-sf2);// dryness fraction
+
+h2_prim = hf2+x2*(hg2-hf2);// specific enthalpy of steam, [kJ/kg]
+
+TO = n_tur*(h1-h2_prim);//theoretical steam turbine output, [kJ/kg]
+TOt = TO*ms/3600;// total theoretical steam turbine output, [MW]
+
+mprintf('\n (c) The theoretical output from the steam turbine is = %f MW\n',TOt);
+
+// (d)
+n_tho = (Po+TOt)*n_the1/Po;// overall theoretical thermal efficiency
+mprintf('\n (d) The overall thermal efficiency is = %f percent\n',n_tho*100);
+
+// End
diff --git a/2705/CH17/EX17.1/Ex17_1.sce b/2705/CH17/EX17.1/Ex17_1.sce new file mode 100755 index 000000000..1222d2ae4 --- /dev/null +++ b/2705/CH17/EX17.1/Ex17_1.sce @@ -0,0 +1,47 @@ +clear;
+clc;
+disp('Example 17.1');
+
+// aim : To determine
+// the indicated and brake output and the mechanicl efficiency
+// draw up an overall energy balance and as % age
+
+// given values
+h = 21;// height of indicator diagram, [mm]
+ic = 27;// indicator calibration, [kN/m^2 per mm]
+sv = 14*10^-3;// swept volume of the cylinder;,[m^3]
+N = 6.6;// speed of engine, [rev/s]
+ebl = 77;// effective brake load, [kg]
+ebr = .7;// effective brake radious, [m]
+fc = .002;// fuel consumption, [kg/s]
+CV = 44000;// calorific value of fuel, [kJ/kg]
+cwc = .15;// cooling water circulation, [kg/s]
+Ti = 38;// cooling water inlet temperature, [C]
+To = 71;// cooling water outlet temperature, [C]
+c = 4.18;// specific heat capacity of water, [kJ/kg]
+eeg = 33.6;// energy to exhaust gases, [kJ/s]
+g = 9.81;// gravitational acceleration, [m/s^2]
+
+// solution
+PM = ic*h;// mean effective pressure, [kN/m^2]
+LA = sv;// swept volume of the cylinder, [m^3]
+ip = PM*LA*N/2;// indicated power,[kW]
+T = ebl*g*ebr;// torque, [N*m]
+bp = 2*%pi*N*T;// brake power, [W]
+n_mech = bp/ip*10^-3;// mechanical efficiency
+mprintf('\n The Indicated power is = %f kW\n',ip);
+mprintf('\n The Brake power is = %f kW\n',bp*10^-3);
+mprintf('\n The mechanical efficiency is = %f percent\n',n_mech);
+
+ef = CV*fc;// energy from fuel, [kJ/s]
+eb = bp*10^-3;// energy to brake power,[kJ/s]
+ec = cwc*c*(To-Ti);// energy to coolant,[kJ/s]
+es = ef-(eb+ec+eeg);// energy to surrounding,[kJ/s]
+
+disp('Energy can be tabulated as :-');
+disp('----------------------------------------------------------------------------------------------------');
+disp(' kJ/s Percentage ')
+disp('----------------------------------------------------------------------------------------------------');
+mprintf('\n Energy from fuel %f %f\n Energy to brake power %f %f\n Energy to coolant %f %f\n Energy to exhaust %f %f\n Energy to suroundings,etc. %f %f\n',ef,ef/ef*100,eb,eb/ef*100,ec,ec/ef*100,eeg,eeg/ef*100,es,es/ef*100);
+
+// End
diff --git a/2705/CH17/EX17.2/Ex17_2.sce b/2705/CH17/EX17.2/Ex17_2.sce new file mode 100755 index 000000000..16f568583 --- /dev/null +++ b/2705/CH17/EX17.2/Ex17_2.sce @@ -0,0 +1,87 @@ +clear;
+clc;
+disp('Example 17.2');
+
+// aim : To determine
+// (a) bp
+// (b) ip
+// (c) mechanical efficiency
+// (d) indicated thermal efficiency
+// (e) brake specific steam consumption
+// (f) draw up complete energy account for the test one-minute basis taking 0 C as datum
+
+// given values
+d = 200*10^-3;// cylinder diameter, [mm]
+L = 250*10^-3;// stroke, [mm]
+N = 5;// speed, [rev/s]
+r = .75/2;// effective radious of brake wheel, [m]
+Ps = 800;// stop valve pressure, [kN/m^2]
+x = .97;// dryness fraction of steam
+BL = 136;// brake load, [kg]
+SL = 90;// spring balance load, [N]
+PM = 232;// mean effective pressure, [kN/m^2]
+Pc = 10;// condenser pressure, [kN/m^2]
+m_dot = 3.36;// steam consumption, [kg/min]
+CC = 113;// condenser cooling water, [kg/min]
+Tr = 11;// temperature rise of condenser cooling water, [K]
+Tc = 38;// condensate temperature, [C]
+C = 4.18;// heat capacity of water, [kJ/kg K]
+g = 9.81;// gravitational acceleration, [m/s^2]
+
+// solution
+// from steam table
+// at 800 kN/m^2
+tf1 = 170.4;// saturation temperature, [C]
+hf1 = 720.9;// [kJ/kg]
+hfg1 = 2046.5;// [kJ/kg]
+hg1 = 2767.5;// [kJ/kg]
+vg1 = .2403;// [m^3/kg]
+
+// at 10 kN/m^2
+tf2 = 45.8;// saturation temperature, [C]
+hf2 = 191.8;// [kJ/kg]
+hfg2 = 2392.9;// [kJ/kg]
+hg2 = 2584.8;// [kJ/kg]
+vg2 = 14.67;// [m^3/kg]
+
+// (a)
+T = (BL*g-SL)*r;// torque, [Nm]
+bp = 2*%pi*N*T*10^-3;// brake power,[W]
+mprintf('\n (a) The brake power is = %f kW\n',bp);
+
+// (b)
+A = %pi*d^2/4;// area, [m^2]
+ip = PM*L*A*N*2;// double-acting so*2, [kW]
+mprintf('\n (b) The indicated power is = %f kW\n',ip);
+
+// (c)
+n_mec = bp/ip;// mechanical efficiency
+mprintf('\n (c) The mechanical efficiency is = %f percent\n',n_mec*100);
+
+// (d)
+h = hf1+x*hfg1;// [kJ/kg]
+hf = hf2;
+ITE = ip/((m_dot/60)*(h-hf));// indicated thermal efficiency
+mprintf('\n (d) The indicated thermal efficiency is = %f percent\n',ITE*100);
+// (e)
+Bsc=m_dot*60/bp;// brake specific steam consumption, [kg/kWh]
+mprintf('\n (e) The brake steam consumption is = %f kg/kWh\n',Bsc);
+
+// (f)
+// energy balanvce reckoned from 0 C
+Es = m_dot*h;// energy supplied, [kJ]
+Eb = bp*60;// energy to bp, [kJ]
+Ecc = CC*C*Tr;// energy to condensate cooling water, [kJ]
+Ec = m_dot*C*Tc;// energy to condensate, [kJ]
+Ese = Es-Eb-Ecc-Ec;// energy to surrounding,etc, [kJ]
+
+mprintf('\n (f) Energy supplied/min is = %f kJ\n',Es);
+
+mprintf('\n Energy to bp/min is = %f kJ\n',Eb);
+mprintf('\n Energy to condenser cooling water/min is = %f kJ\n',Ecc);
+mprintf('\n Energy to condensate/min is = %f kJ\n',Ec);
+mprintf('\n Energy to surrounding, etc/min is = %f kJ\n',Ese);
+
+// answer in the book is misprinted
+
+// End
diff --git a/2705/CH17/EX17.3/Ex17_3.sce b/2705/CH17/EX17.3/Ex17_3.sce new file mode 100755 index 000000000..baddc9cc9 --- /dev/null +++ b/2705/CH17/EX17.3/Ex17_3.sce @@ -0,0 +1,55 @@ +clear;
+clc;
+disp('Example 17.3');
+
+// aim : To determine
+// (a) the brake power
+// (b) the brake specific fuel consumption
+// (c) the indicated thermal efficiency
+// (d) the energy balance, expressing the various items
+
+// given values
+t = 30;// duration of trial, [min]
+N = 1750;// speed of engine, [rev/min]
+T = 330;// brake torque, [Nm]
+mf = 9.35;// fuel consumption, [kg]
+CV = 42300;// calorific value of fuel, [kJ/kg]
+cwc = 483;// jacket cooling water circulation, [kg]
+Ti = 17;// inlet temperature, [C]
+To = 77;// outlet temperature, [C]
+ma = 182;// air consumption, [kg]
+Te = 486;// exhaust temperature, [C]
+Ta = 17;// atmospheric temperature, [C]
+n_mec = .83;// mechanical efficiency
+c = 1.25;// mean specific heat capacity of exhaust gas, [kJ/kg K]
+C = 4.18;// specific heat capacity, [kJ/kg K]
+
+// solution
+// (a)
+bp = 2*%pi*N*T/60*10^-3;// brake power, [kW]
+mprintf('\n (a) The Brake power is = %f kW\n',bp);
+
+// (b)
+bsf = mf*2/bp;//brake specific fuel consumption, [kg/kWh]
+mprintf('\n (b) The brake specific fuel consumption is = %f kg/kWh\n',bsf);
+
+// (c)
+ip = bp/n_mec;// indicated power, [kW]
+ITE = ip/(2*mf*CV/3600);// indicated thermal efficiency
+mprintf('\n (c) The indicated thermal efficiency is = %f percent\n',ITE*100);
+
+// (d)
+// taking basis one minute
+ef = CV*mf/30;// energy from fuel, [kJ]
+eb = bp*60;// energy to brake power,[kJ]
+ec = cwc/30*C*(To-Ti);// energy to cooling water,[kJ]
+ee = (ma+mf)/30*c*(Te-Ta);// energy to exhaust, [kJ]
+es = ef-(eb+ec+ee);// energy to surrounding,etc,[kJ]
+
+mprintf('\n (d) Energy from fuel is = %f kJ\n',ef);
+mprintf('\n Energy to brake power is = %f kJ\n',eb);
+mprintf('\n Energy to cooling water is = %f kJ\n',ec);
+mprintf('\n Energy to exhaust is = %f kJ\n',ee);
+mprintf('\n Energy to surrounding, etc is = %f kJ\n',es);
+
+// End
diff --git a/2705/CH17/EX17.4/Ex17_4.sce b/2705/CH17/EX17.4/Ex17_4.sce new file mode 100755 index 000000000..e50619a8c --- /dev/null +++ b/2705/CH17/EX17.4/Ex17_4.sce @@ -0,0 +1,33 @@ +clear;
+clc;
+disp('Example 17.4');
+
+// aim : To determine
+// (a) the indicated power of the engine
+// (b) the mechanical efficiency of the engine
+
+// given values
+bp = 52;// brake power output, [kW]
+bp1 = 40.5;// brake power of cylinder cut1, [kW]
+bp2 = 40.2;// brake power of cylinder cut2, [kW]
+bp3 = 40.1;// brake power of cylinder cut3, [kW]
+bp4 = 40.6;// brake power of cylinder cut4, [kW]
+bp5 = 40.7;// brake power of cylinder cut5, [kW]
+bp6 = 40.0;// brake power of cylinder cut6, [kW]
+
+// sollution
+ip1 = bp-bp1;// indicated power of cylinder cut1, [kW]
+ip2 = bp-bp2;// indicated power of cylinder cut2, [kW]
+ip3 = bp-bp3;// indicated power of cylinder cut3, [kW]
+ip4 = bp-bp4;// indicated power of cylinder cut4, [kW]
+ip5 = bp-bp5;// indicated power of cylinder cut5, [kW]
+ip6 = bp-bp6;// indicated power of cylinder cut6, [kW]
+
+ip = ip1+ip2+ip3+ip4+ip5+ip6;// indicated power of engine,[kW]
+mprintf('\n (a) The indicated power of the engine is = %f kW\n',ip);
+
+// (b)
+n_mec = bp/ip;// mechanical efficiency
+mprintf('\n (b) The mechanical efficiency of the engine is = %f percent\n',n_mec*100);
+
+// End
diff --git a/2705/CH17/EX17.5/Ex17_5.sce b/2705/CH17/EX17.5/Ex17_5.sce new file mode 100755 index 000000000..23733b131 --- /dev/null +++ b/2705/CH17/EX17.5/Ex17_5.sce @@ -0,0 +1,61 @@ +clear;
+clc;
+disp('Example 17.5');
+
+// aim : To determine
+// the brake power,indicated power and mechanicl efficiency
+// draw up an energy balance and as % age of the energy supplied
+
+// given values
+N = 50;// speed, [rev/s]
+BL = 267;// break load.,[N]
+BL1 = 178;// break load of cylinder cut1, [N]
+BL2 = 187;// break load of cylinder cut2, [N]
+BL3 = 182;// break load of cylinder cut3, [N]
+BL4 = 182;// break load of cylinder cut4, [N]
+
+FC = .568/130;// fuel consumption, [L/s]
+s = .72;// specific gravity of fuel
+CV = 43000;// calorific value of fuel, [kJ/kg]
+
+Te = 760;// exhaust temperature, [C]
+c = 1.015;// specific heat capacity of exhaust gas, [kJ/kg K]
+Ti = 18;// cooling water inlet temperature, [C]
+To = 56;// cooling water outlet temperature, [C]
+mw = .28;// cooling water flow rate, [kg/s]
+Ta = 21;// ambient tempearture, [C]
+C = 4.18;// specific heat capacity of cooling water, [kJ/kg K]
+
+// solution
+bp = BL*N/455;// brake power of engine, [kW]
+bp1 = BL1*N/455;// brake power of cylinder cut1, [kW]
+i1 = bp-bp1;// indicated power of cylinder cut1, [kW]
+bp2 = BL2*N/455;// brake power of cylinder cut2, [kW]
+i2 = bp-bp2;// indicated power of cylinder cut2, [kW]
+bp3 = BL3*N/455;// brake power of cylinder cut3, [kW]
+i3 = bp-bp3;// indicated power of cylinder cut3, [kW]
+bp4 = BL4*N/455;// brake power of cylinder cut4, [kW]
+i4 = bp-bp4;// indicated power of cylinder cut4, [kW]
+
+ip = i1+i2+i3+i4;// indicated power of engine, [kW]
+n_mec = bp/ip;// mechanical efficiency
+
+mprintf('\n The Brake power is = %f kW\n',bp);
+mprintf('\n The Indicated power is = %f kW\n',ip);
+mprintf('\n The mechanical efficiency is = %f percent\n',n_mec*100);
+
+mf = FC*s;// mass of fuel/s, [kg]
+ef = CV*mf;// energy from fuel/s, [kJ]
+me = 15*mf;// mass of exhaust/s,[kg],(given in condition)
+ee = me*c*(Te-Ta);// energy to exhaust/s,[kJ]
+ec = mw*C*(To-Ti);// energy to cooling water/s,[kJ]
+es = ef-(ee+ec+bp);// energy to surrounding,etc/s,[kJ]
+
+disp('Energy can be tabulated as :-');
+disp('----------------------------------------------------------------------------------------------------');
+disp(' kJ/s Percentage ')
+disp('----------------------------------------------------------------------------------------------------');
+mprintf('\n Energy from fuel %f %f\n Energy to brake power %f %f\n Energy to exhaust %f %f\n Energy to coolant %f %f\n Energy to suroundings,etc. %f %f\n',ef,ef/ef*100,bp,bp/ef*100,ee,ee/ef*100,ec,ec/ef*100,es,es/ef*100);
+
+// there is minor variation in the result reported in the book
+// End
diff --git a/2705/CH17/EX17.6/Ex17_6.sce b/2705/CH17/EX17.6/Ex17_6.sce new file mode 100755 index 000000000..7f34d5492 --- /dev/null +++ b/2705/CH17/EX17.6/Ex17_6.sce @@ -0,0 +1,33 @@ +clear;
+clc;
+disp('Example 17.6');
+
+// aim : To determine
+// (a) the break power of engine
+// (b) the fuel consumption of the engine
+// (c) the brake thermal efficiency of the engine
+
+// given values
+d = 850*10^-3;// bore , [m]
+L = 2200*10^-3;// stroke, [m]
+PMb = 15;// BMEP of cylinder, [bar]
+N = 95/60;// speed of engine, [rev/s]
+sfc = .2;// specific fuel oil consumption, [kg/kWh]
+CV = 43000;// calorific value of the fuel oil, [kJ/kg]
+
+// solution
+// (a)
+A = %pi*d^2/4;// area, [m^2]
+bp = PMb*L*A*N*8/10;// brake power,[MW]
+mprintf('\n (a) The brake power is = %f MW\n',bp);
+
+ // (b)
+ FC = bp*sfc;// fuel consumption, [kg/h]
+ mprintf('\n (b) The fuel consumption is = %f tonne/h\n',FC);
+
+ // (c)
+ mf = FC/3600;// fuel used, [kg/s]
+ n_the = bp/(mf*CV);// brake thermal efficiency
+ mprintf('\n (c) The brake thermal efficiency is = %f percent\n',n_the*100);
+
+ // End
diff --git a/2705/CH18/EX18.1/Ex18_1.sce b/2705/CH18/EX18.1/Ex18_1.sce new file mode 100755 index 000000000..85da4efdc --- /dev/null +++ b/2705/CH18/EX18.1/Ex18_1.sce @@ -0,0 +1,61 @@ +clear;
+clc;
+disp('Example 18.1');
+
+// aim : To determine
+// (a) the coefficient of performance
+// (b) the mass flow of the refrigerant
+// (c) the cooling water required by the condenser
+
+// given values
+P1 = 462.47;// pressure limit, [kN/m^2]
+P3 = 1785.90;// pressure limit, [kN/m^2]
+T2 = 273+59;// entering saturation temperature, [K]
+T5 = 273+32;// exit temperature of condenser, [K]
+d = 75*10^-3;// bore, [m]
+L = d;// stroke, [m]
+N = 8;// engine speed, [rev/s]
+VE = .8;// olumetric efficiency
+cpL = 1.32;// heat capacity of liquid, [kJ/kg K]
+c = 4.187;// heat capacity of water, [kj/kg K]
+
+// solution
+// from given table
+// at P1
+h1 = 231.4;// specific enthalpy, [kJ/kg]
+s1 = .8614;// specific entropy,[ kJ/kg K
+v1 = .04573;// specific volume, [m^3/kg]
+
+// at P3
+h3 = 246.4;// specific enthalpy, [kJ/kg]
+s3 = .8093;// specific entropy,[ kJ/kg K
+v3 = .04573;// specific volume, [m^3/kg]
+T3= 273+40;// saturation temperature, [K]
+h4 = 99.27;// specific enthalpy, [kJ/kg]
+// (a)
+s2 = s1;// specific entropy, [kJ/kg k]
+// using s2=s3+cpv*log(T2/T3)
+cpv = (s2-s3)/log(T2/T3);// heat capacity, [kj/kg k]
+
+// from Fig.18.8
+T4 = T3;
+h2 = h3+cpv*(T2-T3);// specific enthalpy, [kJ/kg]
+h5 = h4-cpL*(T4-T5);// specific enthalpy, [kJ/kg]
+h6 = h5;
+COP = (h1-h6)/(h2-h1);// coefficient of performance
+mprintf('\n (a) The coefficient of performance of the refrigerator is = %f\n',COP);
+
+// (b)
+SV = %pi/4*d^2*L;// swept volume of compressor/rev, [m^3]
+ESV = SV*VE*N*3600;// effective swept volume/h, [m^3]
+m = ESV/v1;// mass flow of refrigerant/h,[kg]
+mprintf('\n (b) The mass flow of refrigerant/h is = %f kg\n',m);
+
+// (c)
+dT = 12;// temperature limit, [C]
+Q = m*(h2-h5);// heat transfer in condenser/h, [kJ]
+// using Q=m_dot*c*dT, so
+m_dot = Q/(c*dT);// mass flow of water required, [kg/h]
+mprintf('\n (c) The mass flow of water required is = %f kg/h\n',m_dot);
+
+// End
diff --git a/2705/CH18/EX18.2/Ex18_2.sce b/2705/CH18/EX18.2/Ex18_2.sce new file mode 100755 index 000000000..7d917dfd9 --- /dev/null +++ b/2705/CH18/EX18.2/Ex18_2.sce @@ -0,0 +1,54 @@ +clear;
+clc;
+disp('Example 18.2');
+
+// aim : To determine
+// (a) the mass flow of R401
+// (b) the dryness fraction of R401 at the entry to the evaporator
+// (c) the power of driving motor
+// (d) the ratio of heat transferred from condenser to the power required to the motor
+
+// given values
+P1 = 411.2;// pressure limit, [kN/m^2]
+P3 = 1118.9;// pressure limit, [kN/m^2]
+Q = 100*10^3;// heat transfer from the condenser,[kJ/h]
+T2 = 273+60;// entering saturation temperature, [K]
+
+// given
+// from given table
+// at P1
+h1 = 409.3;// specific enthalpy, [kJ/kg]
+s1 = 1.7431;// specific entropy,[ kJ/kg K
+
+// at P3
+h3 = 426.4;// specific enthalpy, [kJ/kg]
+s3 = 1.7192;// specific entropy,[ kJ/kg K
+T3 = 273+50;// saturation temperature, [K]
+h4 = 265.5;// specific enthalpy, [kJ/kg]
+// (a)
+s2 = s1;// specific entropy, [kJ/kg k]
+// using s2=s3+cpv*log(T2/T3)
+cpv = (s2-s3)/log(T2/T3);// heat capacity, [kj/kg k]
+
+// from Fig.18.8
+h2 = h3+cpv*(T2-T3);// specific enthalpy, [kJ/kg]
+Qc = h2-h4;// heat transfer from condenser, [kJ/kg]
+mR401 = Q/Qc;// mass flow of R401, [kg]
+ mprintf('\n (a) The mass flow of R401 is = %f kg/h\n',mR401);
+
+// (b)
+hf1 = 219;// specific enthalpy, [kJ/kg]
+h5 = h4;
+// using h5=hf1+s5*(h1-hf1),so
+x5 = (h5-hf1)/(h1-hf1);// dryness fraction
+mprintf('\n (b) The dryness fraction of R401 at the entry to the evaporator is = %f\n',x5);
+
+// (c)
+P = mR401*(h2-h1)/3600/.7;// power to driving motor, [kW]
+ mprintf('\n (c) The power to driving motor is = %f kW\n',P);
+
+// (d)
+r = Q/3600/P;// ratio
+mprintf('\n (d) The ratio of heat transferred from condenser to the power required to the motor is = %f : 1\n',r);
+
+// End
diff --git a/2705/CH19/EX19.1/Ex19_1.sce b/2705/CH19/EX19.1/Ex19_1.sce new file mode 100755 index 000000000..feed53150 --- /dev/null +++ b/2705/CH19/EX19.1/Ex19_1.sce @@ -0,0 +1,46 @@ +clear;
+clc;
+disp('Example 19.1');
+
+// aim : To compare the moisture content and the true specific volumes of atmosphere air
+// (a) temperature is 12 C and the air is saturaded
+// (b) temperature is 31 C and air is .75 saturated
+
+// Given values
+P_atm = 101.4;// atmospheric pressure, [kN/m^2]
+R = .287;// [kJ/kg K]
+
+// solution
+// (a)
+T = 273+12;// air temperature, [K]
+// From steam table at 12 C
+p = 1.4;// [kN/m^2]
+vg = 93.9;// [m^3/kg]
+pa = P_atm-p;// partial pressure of the dry air, [kN/m^2]
+va = R*T/pa;// [m^3/kg]
+
+mw = va/vg;// mass of water vapor in the air,[kg]
+v = va/(1+mw);// specific volume of humid air, [m^3/kg]
+
+mprintf('\n (a) The mass of water vapor in the humid air is = %f kg\n',mw);
+mprintf('\n The specific volume of humid air is = %f m^3/kg\n',v);
+
+// (b)
+x = .75;// dryness fraction
+T = 273+31;// air temperature, [K]
+// From steam table
+p = 4.5;// [kN/m^2]
+vg = 31.1;// [m^3/kg]
+pa = P_atm-p;// [kN/m^2]
+va = R*T/pa;// [m^3/kg]
+mw1= va/vg;// mass of water vapor in the air, [kg]
+mw_actual = mw1*x;// actual mass of vapor, [kg]
+v = va/(1+mw_actual);// true specific volume of humid air,[m^3/kg]
+
+mprintf('\n (b) The mass of water vapor in the humid air is = %f kg\n',mw1);
+mprintf('\n The specific volume of humid air is = %f m^3/kg\n',v);
+
+ewv = mw_actual/mw ;
+mprintf('\n On the warm day the air conteains %f times the mass of water vapor as on the cool day \n',ewv);
+
+// End
diff --git a/2705/CH19/EX19.2/Ex19_2.sce b/2705/CH19/EX19.2/Ex19_2.sce new file mode 100755 index 000000000..99dc20724 --- /dev/null +++ b/2705/CH19/EX19.2/Ex19_2.sce @@ -0,0 +1,34 @@ +clear;
+clc;
+disp('Example 19.2');
+
+// aim : To determine
+// (a) the partial pressures of the vapor and the dry air
+// (b) the specific humidity of the mixture
+// (c) the composition of the mixture
+
+// Given values
+phi = .65;// Relative humidity
+T = 2733+20;// temperature, [K]
+p = 100;// barometric pressure, [kN/m^2]
+
+// solution
+// (a)
+// From the steam table at 20 C
+pg = 2.34;// [kN/m^2]
+ps = phi*pg;// partial pressure of vapor, [kN/m^2]
+pa = p-ps;// partial pressure of dry air, [kN/m^2]
+mprintf('\n (a) The partial pressure of vapor is = %f kN/m^2\n',ps);
+mprintf('\n The partial pressure of dry air is = %f kN/m^2\n',pa);
+
+// (b)
+// from equation [15]
+omega = .622*ps/(p-ps);// specific humidity of the mixture
+mprintf('\n (b) The specific humidity of the mixture is = %f kg/kg dry air\n',omega);
+
+// (c)
+// using eqn [1] from section 19.2
+y = 1/(1+omega);// composition of the mixture
+mprintf('\n (c) The composition of the mixture is = %f\n',y);
+
+// End
diff --git a/2705/CH19/EX19.3/Ex19_3.sce b/2705/CH19/EX19.3/Ex19_3.sce new file mode 100755 index 000000000..54f4d0111 --- /dev/null +++ b/2705/CH19/EX19.3/Ex19_3.sce @@ -0,0 +1,52 @@ +clear;
+clc;
+disp('Example 19.3');
+
+// aim : To determine
+// (a) the specific humidity
+// (b) the dew point
+// (c) the degree of superheat of the superheated vapor
+// (d) the mass of condensate formed per kg of dry air if the moist air is cooled to 12 C
+
+// Given values
+t = 25;// C
+T = 273+25;// moist air temperature, [K]
+phi = .6;// relative humidity
+p = 101.3;// barometric pressure, [kN/m^2]
+R = .287;// [kJ/kg K]
+
+// solution
+// (a)
+// From steam table at 25 C
+pg = 3.17;// [kN/m^2]
+ps = phi*pg;// partial pressure of the vapor, [kN/m^2]
+omega = .622*ps/(p-ps);// the specific humidity of air
+
+mprintf('\n (a) The specific humidity is = %f kg/kg air\n',omega);
+
+// (b)
+// Dew point is saturated temperature at ps is,
+t_dew = 16+2*(1.092-1.817)/(2.062-1.817);// [C]
+mprintf('\n (b) The dew point is = %f C\n',t_dew);
+
+// (c)
+Dos = t-t_dew;// degree of superheat, [C]
+mprintf('\n (c) The degree of superheat is = %f C\n',Dos);
+
+// (d)
+// at 25 C
+pa = p-ps;// [kN/m^2]
+va = R*T/pa;// [m^3/kg]
+// at 16.69 C
+vg = 73.4-(73.4-65.1)*.69/2;// [m^3/kg]
+ms1= va/vg;
+// at 12 C
+vg = 93.8;// [m^3/kg]
+ms2 = va/vg;
+
+m = ms1-ms2;// mas of condensate
+mprintf('\n (d) The mass of condensate is = %f kg/kg dry air\n',m);
+
+// there is calculation mistake in the book so answer is no matching
+
+// End
diff --git a/2705/CH19/EX19.4/Ex19_4.sce b/2705/CH19/EX19.4/Ex19_4.sce new file mode 100755 index 000000000..0cec4f91c --- /dev/null +++ b/2705/CH19/EX19.4/Ex19_4.sce @@ -0,0 +1,73 @@ +clear;
+clc;
+disp(' Example 19.4');
+
+// aim : To determine
+// (a) the volume of external saturated air
+// (b) the mass of air
+// (c) the heat transfer
+// (d) the heat transfer required by the combind water vapour
+
+// given values
+Vb = 56000;// volume of building, [m^3]
+T2 = 273+20;// temperature of air in thebuilding, [K]
+phi = .6;// relative humidity
+T1 = 8+273;// external air saturated temperature, [K]
+p0 = 101.3;// atmospheric pressure, [kN/m^2]
+cp = 2.093;// heat capacity of saturated steam, [kJ/kg K]
+R = .287;// gas constant, [kJ/kg K]
+
+// solution
+// from steam table at 20 C saturation pressure of steam is,
+pg = 2.34;// [kN/m^2]
+
+// (a)
+pvap = phi*pg;// partial pressure of vapor, [kN/m^2]
+P = p0-pvap;// partial pressure of air, [kN/m^2]
+V = 2*Vb;// air required, [m^3]
+// at 8 C saturation pressure ia
+pvap = 1.072;// [kN/m^2]
+P2 = p0-pvap;// partial pressure of entry at 8 C, [kN/m^2]
+
+// using P1*V1/T1=P2*V2/T2;
+V2 = P*V*T1/(T2*P2);// air required at 8 C, [m^3/h]
+mprintf('\n (a) The volume of air required is = %f m^3/h\n',V2);
+
+// (b)
+// assuming
+pg = 1.401;// pressure, [kN/m^2]
+Tg = 273+12;// [K]
+vg = 93.8;// [m^3/kg]
+// at constant pressure
+v = vg*T2/Tg;// volume[m^3/kg]
+mv = V/v;// mass of vapor in building at 20 C, [kg/h]
+// from steam table at 8 C
+vg2 = 121;// [m^3/kg]
+mve = V2/vg2;// mass of vapor supplied with saturated entry air, [kg/h]
+mw = mv-mve;// mass of water added, [kg/h]
+mprintf('\n (b) The mass of water added is = %f kg/h\n ',mw);
+
+// (c)
+// for perfect gas
+m = P2*V2/(R*T1);// [kg/h]
+Cp = .287;// heat capacity, [kJ/kg K]
+Q = m*Cp*(T2-T1);// heat transfer by dry air,[kJ/h]
+mprintf('\n (c) The heat transfer required by dry air is = %f MJ/h\n',Q*10^-3);
+
+// (d)
+// from steam table
+h1 = 2516.2;// specific enthalpy of saturated vapor at 8 C,[kJ/kg]
+hs = 2523.6;// specific enthalpy of saturated vapor at 20 C, [kJ/kg]
+h2 = hs+cp*(T2-T1);// specific enthalpy of vapor at 20 c, [kJ/kg]
+Q1 = mve*(h2-h1);// heat transfer required for vapor, [kJ]
+
+// again from steam table
+hf1 = 33.6;// [kJ/kg]
+hg3 = 2538.2;// [kJ/kg]
+Q2 = mw*(hg3-hf1);// heat transfer required for water, [kJ/h]
+Qt = Q1+Q2;// total heat transfer, [kJ/h]
+mprintf('\n (d) The heat transferred required for vapor+supply water is = %f MJ/h\n',Qt*10^-3);
+
+// there is minor variation in the answer reported in the book
+
+// End
diff --git a/2705/CH2/EX2.1/Ex2_1.sce b/2705/CH2/EX2.1/Ex2_1.sce new file mode 100755 index 000000000..1d5f07b56 --- /dev/null +++ b/2705/CH2/EX2.1/Ex2_1.sce @@ -0,0 +1,26 @@ +clear; +clc; +disp('Example 2.1'); + + + +// Given values +Q = 2500; // Heat transferred into the system, [kJ] +W = 1400; // Work transferred from the system, [kJ] + +// solution + +// since process carried out on a closed system, so using equation [4] +del_E = Q-W; // Change in total energy, [kJ] + +mprintf('\n The Change in total energy is, del_E = %f kJ\n',del_E); + +if(del_E>0) + disp('Since del_E is positive, so there is an increase in total enery') +else + disp('Since del_E is negative, so there is an decrease in total enery') +end + +// There is mistake in the book's results unit + +// End diff --git a/2705/CH2/EX2.2/Ex2_2.sce b/2705/CH2/EX2.2/Ex2_2.sce new file mode 100755 index 000000000..095f933f2 --- /dev/null +++ b/2705/CH2/EX2.2/Ex2_2.sce @@ -0,0 +1,22 @@ +clear; +clc; +disp('Example 2.2'); + + +// Given values +del_E = 3500; // Increase in total energy of the system, [kJ] +W = -4200; // Work transfer into the system, [kJ] + +// solution +// since process carried out on a closed system, so using equation [3] +Q = del_E+W;// [kJ] + +mprintf('\n The Heat transfer is, Q = %f kJ \n',Q); + +if(Q>0) + disp('Since Q>0, so heat is transferred into the system') +else + disp('Since Q<0, so heat is transferred from the system') +end + +// End diff --git a/2705/CH2/EX2.3/Ex2_3.sce b/2705/CH2/EX2.3/Ex2_3.sce new file mode 100755 index 000000000..0f6f799d4 --- /dev/null +++ b/2705/CH2/EX2.3/Ex2_3.sce @@ -0,0 +1,23 @@ +clear; +clc; +disp('Example 2.3'); + + + +// Given values +Q = -150; // Heat transferred out of the system, [kJ/kg] +del_u = -400; // Internal energy decreased ,[kJ/kg] + +// solution +// using equation [3],the non flow energy equation +// Q=del_u+W +W = Q-del_u; // [kJ/kg] +mprintf('\n The Work done is, W = %f kJ/kg \n',W); + +if(W>0) + disp('Since W>0, so Work done by the engine per kilogram of working substance') +else + disp('Since <0, so Work done on the engine per kilogram of working substance') +end + +// End diff --git a/2705/CH2/EX2.4/Ex2_4.sce b/2705/CH2/EX2.4/Ex2_4.sce new file mode 100755 index 000000000..9102fc8b3 --- /dev/null +++ b/2705/CH2/EX2.4/Ex2_4.sce @@ -0,0 +1,43 @@ +clear; +clc; +disp('Example 2.4'); + + + +// Given values +m_dot = 4; // fluid flow rate, [kg/s] +Q = -40; // Heat loss to the surrounding, [kJ/kg] + +// At inlet +P1 = 600; // pressure ,[kn/m^2] +C1 = 220; // velocity ,[m/s] +u1 = 2200; // internal energy, [kJ/kg] +v1 = .42; // specific volume, [m^3/kg] + +// At outlet +P2 = 150; // pressure, [kN/m^2] +C2 = 145; // velocity, [m/s] +u2 = 1650; // internal energy, [kJ/kg] +v2 = 1.5; // specific volume, [m^3/kg] + +// solution +// for steady flow energy equation for the open system is given by +// u1+P1*v1+C1^2/2+Q=u2+P2*v2+C2^2/2+W +// hence + +W = (u1-u2)+(P1*v1-P2*v2)+(C1^2/2-C2^2/2)*10^-3+Q; // [kJ/kg] + +mprintf('\n workdone is, W = %f kJ/kg ',W); + +if(W>0) + disp('Since W>0, so Power is output from the system') +else + disp('Since <0, so Power is input to the system') +end + +// Hence + +P_out = W*m_dot; // power out put from the system, [kW] +mprintf('\n The power output from the system is = %f kW \n',P_out); + +// End diff --git a/2705/CH2/EX2.5/Ex2_5.sce b/2705/CH2/EX2.5/Ex2_5.sce new file mode 100755 index 000000000..f43f37c08 --- /dev/null +++ b/2705/CH2/EX2.5/Ex2_5.sce @@ -0,0 +1,27 @@ +clear; +clc; +disp('Example 2.5'); + + + +// Given values +del_P = 154.45; // pressure difference across the die, [MN/m^2] +rho = 11360; // Density of the lead, [kg/m^3] +c = 130; // specific heat capacity of the lead, [J/kg*K] + +// solution +// since there is no cooling and no externel work is done, so energy balane becomes +// P1*V1+U1=P2*V2+U2 ,so +// del_U=U2-U1=P1*V1-P2*V2 + +// also, for temperature rise, del_U=m*c*t, where, m is mass; c is specific heat capacity; and t is temperature rise + +// Also given that lead is incompressible, so V1=V2=V and assuming one m^3 of lead + +// using above equations +t = del_P/(rho*c)*10^6 ;// temperature rise [C] + +mprintf('\n The temperature rise of the lead is = %f C\n',t); + +// End + diff --git a/2705/CH2/EX2.6/Ex2_6.sce b/2705/CH2/EX2.6/Ex2_6.sce new file mode 100755 index 000000000..186ca15e2 --- /dev/null +++ b/2705/CH2/EX2.6/Ex2_6.sce @@ -0,0 +1,38 @@ +clear; +clc; +disp('Example 2.6'); + + +// Given values +m_dot = 4.5; // mass flow rate of air, [kg/s] +Q = -40; // Heat transfer loss, [kJ/kg] +del_h = -200; // specific enthalpy reduce, [kJ/kg] + +C1 = 90; // inlet velocity, [m/s] +v1 = .85; // inlet specific volume, [m^3/kg] + +v2 = 1.45; // exit specific volume, [m^3/kg] +A2 = .038; // exit area of turbine, [m^2] + +// solution + +// part (a) +// At inlet, by equation[4], m_dot=A1*C1/v1 +A1 = m_dot*v1/C1;//inlet area, [m^2] +mprintf('\n (a) The inlet area is, A1 = %f m^2 \n',A1); + +// part (b), +// At outlet, since mass flow rate is same, so m_dot=A2*C2/v2, hence +C2 = m_dot*v2/A2; // Exit velocity,[m/s] +mprintf('\n (b) The exit velocity is, C2 = %f m/s \n',C2); + +// part (c) +// using steady flow equation, h1+C1^2/2+Q=h2+C2^2/2+W +W = -del_h+(C1^2/2-C2^2/2)*10^-3+Q; // [kJ/kg] + +// Hence power developed is +P = W*m_dot;// [kW] +mprintf('\n (c) The power developed by the turbine system is = %f kW \n',P); + +// End + diff --git a/2705/CH4/EX4.1/Ex4_1.sce b/2705/CH4/EX4.1/Ex4_1.sce new file mode 100755 index 000000000..afa29662b --- /dev/null +++ b/2705/CH4/EX4.1/Ex4_1.sce @@ -0,0 +1,23 @@ +clear;
+clc;
+disp('Example 4.1');
+
+// aim : To determine
+// the enthalpy
+
+// Given values
+P = .50;// Pressure, [MN/m^2]
+
+// solution
+
+// From steam tables, at given pressure
+hf = 640.1;// specific liquid enthalpy ,[kJ/kg]
+hfg = 2107.4;// specific enthalpy of evaporation ,[kJ/kg]
+hg = 2747.5; // specific enthalpy of dry saturated steam ,[kJ/kg]
+tf = 151.8; // saturation temperature,[C]
+
+mprintf('\n The specific liquid enthalpy is = %f kJ/kg \n',hf);
+mprintf('\n The specific enthalpy of evaporation is = %f kJ/kg \n',hfg);
+mprintf('\n The specific enthalpy of dry saturated steam is = %f kJ/kg \n',hg);
+
+// End
diff --git a/2705/CH4/EX4.10/Ex4_10.sce b/2705/CH4/EX4.10/Ex4_10.sce new file mode 100755 index 000000000..972a1eed3 --- /dev/null +++ b/2705/CH4/EX4.10/Ex4_10.sce @@ -0,0 +1,38 @@ +clear;
+clc;
+disp('Example .10');
+
+// aim : To determine
+// (a) the mass of steam entering the heater
+// (b) the mass of water entering the heater
+
+// Given values
+x = .95;// Dryness fraction
+P = .7;// pressure,[MN/m^2]
+d = 25;// internal diameter of heater,[mm]
+C = 12; // steam velocity in the pipe,[m/s]
+
+// solution
+// from steam table at .7 MN/m^2 pressure
+hf = 697.1;// [kJ/kg]
+hfg = 2064.9;// [kJ/kg]
+hg = 2762.0; // [kJ/kg]
+vg = .273; // [m^3/kg]
+
+// (a)
+v = x*vg; // [m^3/kg]
+ms_dot = %pi*(d*10^-3)^2*C*3600/(4*v);// mass of steam entering, [kg/h]
+mprintf('\n (a) The mass of steam entering the heater is = %f kg/h \n',ms_dot);
+
+// (b)
+h = hf+x*hfg;// specific enthalpy of steam entering heater,[kJ/kg]
+// again from steam tables
+hf1 = 376.8;// [kJ/kg] at 90 C
+hf2 = 79.8;// [kJ/kg] at 19 C
+
+// using energy balance,mw_dot*(hf1-hf2)=ms_dot*(h-hf1)
+mw_dot = ms_dot*(h-hf1)/(hf1-hf2);// mass of water entering to heater,[kg/h]
+
+mprintf('\n (b) The mass of water entering the heater is = %f kg/h \n',mw_dot);
+
+// End
diff --git a/2705/CH4/EX4.11/Ex4_11.sce b/2705/CH4/EX4.11/Ex4_11.sce new file mode 100755 index 000000000..89819556c --- /dev/null +++ b/2705/CH4/EX4.11/Ex4_11.sce @@ -0,0 +1,40 @@ +clear;
+clc;
+disp('Example 4.11');
+
+// aim: To determine
+// the change of internal energy
+
+// Given values
+m = 1.5;// mass of steam,[kg]
+P1 = 1;// initial pressure, [MN/m^2]
+t = 225;// temperature, [C]
+P2 = .28;// final pressure, [MN/m^2]
+x = .9;// dryness fraction of steam at P2
+
+// solution
+
+// from steam table at P1
+h1 = 2886;// [kJ/kg]
+v1 = .2198; // [m^3/kg]
+// hence
+u1 = h1-P1*v1*10^3;// internal energy [kJ/kg]
+
+// at P2
+hf2 = 551.4;// [kJ/kg]
+hfg2 = 2170.1;// [kJ/kg]
+vg2 = .646; // [m^3/kg]
+// so
+h2 = hf2+x*hfg2;// [kj/kg]
+v2 = x*vg2;// [m^3/kg]
+
+// now
+u2 = h2-P2*v2*10^3;// [kJ/kg]
+
+// hence change in specific internal energy is
+del_u = u2-u1;// [kJ/kg]
+
+del_u = m*del_u;// [kJ];
+mprintf('\n The change in internal energy is = %f kJ \n',del_u);
+
+// End
diff --git a/2705/CH4/EX4.12/Ex4_12.sce b/2705/CH4/EX4.12/Ex4_12.sce new file mode 100755 index 000000000..2ef1bbed3 --- /dev/null +++ b/2705/CH4/EX4.12/Ex4_12.sce @@ -0,0 +1,29 @@ +clear;
+clc;
+disp('Example 4.12');
+
+// aim : To determine
+// the dryness fraction of steam after throttling
+
+// given values
+P1 = 1.4;// pressure before throttling, [MN/m^2]
+x1 = .7;// dryness fraction before throttling
+P2 = .11;// pressure after throttling, [MN/m^2]
+
+// solution
+// from steam table
+hf1 = 830.1;// [kJ/kg]
+hfg1 = 1957.7;// [kJ/kg]
+h1 = hf1 + x1*hfg1; // [kJ/kg]
+
+hf2 = 428.8;// [kJ/kg]
+hfg2 = 2250.8;// [kJ/kg]
+
+// now for throttling,
+// hf1+x1*hfg1=hf2+x2*hfg2; where x2 is dryness fraction after throttling
+
+x2=(h1-hf2)/hfg2; // final dryness fraction
+
+mprintf('\n Dryness fraction of steam after throttling is = %f \n',x2);
+
+// End
diff --git a/2705/CH4/EX4.13/Ex4_13.sce b/2705/CH4/EX4.13/Ex4_13.sce new file mode 100755 index 000000000..108099539 --- /dev/null +++ b/2705/CH4/EX4.13/Ex4_13.sce @@ -0,0 +1,65 @@ +clear;
+clc;
+disp('Example 4.13');
+
+// aim : To determine
+// the dryness fraction of steam
+// and the internal diameter of the pipe
+
+// Given values
+
+// steam1
+P1 = 2;// pressure before throttling, [MN/m^2]
+t = 300;// temperature,[C]
+ms1_dot = 2;// steam flow rate, [kg/s]
+P2 = 800;// pressure after throttling, [kN/m^2]
+
+// steam2
+P = 800;// pressure, [N/m^2]
+x2 = .9;// dryness fraction
+ms2_dot = 5; // [kg/s]
+
+// solution
+// (a)
+// from steam table specific enthalpy of steam1 before throttling is
+hf1 = 3025;// [kJ/kg]
+// for throttling process specific enthalpy will same so final specific enthalpy of steam1 is
+hf2 = hf1;
+// hence
+h1 = ms1_dot*hf2;// [kJ/s]
+
+// calculation of specific enthalpy of steam2
+hf2 = 720.9;// [kJ/kg]
+hfg2 = 2046.5;// [kJ/kg]
+// hence
+h2 = hf2+x2*hfg2;// specific enthalpy, [kJ/kg]
+h2 = ms2_dot*h2;// total enthalpy, [kJ/s]
+
+// after mixing
+m_dot = ms1_dot+ms2_dot;// total mass of mixture,[kg/s]
+h = h1+h2;// Total enthalpy of the mixture,[kJ/s]
+h = h/7;// [kJ/kg]
+
+// At pressure 800 N/m^2
+hf = 720.9;// [kJ/kg]
+hfg = 2046.5;// [kJ/kg]
+// so total enthalpy is,hf+x*hfg, where x is dryness fraction of mixture and which is equal to h
+// hence
+x = (h-hf)/hfg;// dryness fraction after mixing
+mprintf('\n (a) The condition of the resulting mixture is dry with dryness fraction = %f \n',x);
+
+// (b)
+// Given
+C = 15;// velocity, [m/s]
+// from steam table
+v = .1255;// [m^/kg]
+A = ms1_dot*v/C;// area, [m^2]
+// using ms1_dot = A*C/v, where A is cross section area in m^2 and
+// A = %pi*d^2/4, where d is diameter of the pipe
+
+// calculation of d
+d = sqrt(4*A/%pi); // diameter, [m]
+
+mprintf('\n (b) The internal diameter of the pipe is = %f mm \n',d*1000);
+
+// End
diff --git a/2705/CH4/EX4.14/Ex4_14.sce b/2705/CH4/EX4.14/Ex4_14.sce new file mode 100755 index 000000000..caec80859 --- /dev/null +++ b/2705/CH4/EX4.14/Ex4_14.sce @@ -0,0 +1,17 @@ +clear;
+clc;
+disp('Example 4.14');
+
+// aim : To estimate
+// the dryness fraction
+
+// Given values
+M = 1.8;// mass of condensate, [kg]
+m = .2;// water collected, [kg]
+
+// solution
+x = M/(M+m);// formula for calculation of dryness fraction using seprating calorimeter
+
+mprintf(' \n The dryness fraction of the steam entering seprating calorimeter is = %f \n',x);
+
+// End
diff --git a/2705/CH4/EX4.15/Ex4_15.sce b/2705/CH4/EX4.15/Ex4_15.sce new file mode 100755 index 000000000..e28726c11 --- /dev/null +++ b/2705/CH4/EX4.15/Ex4_15.sce @@ -0,0 +1,51 @@ +clear;
+clc;
+disp('Example 4.15');
+
+// aim : To determine
+// the dryness fraction of the steam at 2.2 MN/m^2
+
+// Given values
+P1 = 2.2;// [MN/m^2]
+P2 = .13;// [MN/m^2]
+t2 = 112;// [C]
+tf2 = 150;// temperature, [C]
+
+// solution
+// from steam table, at 2.2 MN/m^2
+// saturated steam at 2 MN/m^2 Pressure
+hf1 = 931;// [kJ/kg]
+hfg1 = 1870;// [kJ/kg]
+hg1 = 2801;// [kJ/kg]
+
+// for superheated steam
+// at .1 MN/m^2
+hg2 = 2675;// [kJ/kg]
+hg2_150 = 2777;// specific enthalpy at 150 C, [kJ/kg]
+tf2 = 99.6;// saturation temperature, [C]
+
+// at .5 MN/m^2
+hg3 = 2693;// [kJ/kg]
+hg3_150 = 2773;// specific enthalpy at 150 C, [kJ/kg]
+tf3 = 111.4;// saturation temperature, [C]
+
+Table_P_h1 = [[.1,.5];[hg2,hg3]];// where, P in MN/m^2 and h in [kJ/kg]
+hg = interpln(Table_P_h1,.13);// specific entahlpy at .13 MN/m^2, [kJ/kg]
+
+Table_P_h2 = [[.1,.5];[hg2_150,hg3_150]];// where, P in MN/m^2 and h in [kJ/kg]
+hg_150 = interpln(Table_P_h2,.13);// specific entahlpy at .13 MN/m^2 and 150 C, [kJ/kg]
+
+Table_P_tf = [[.1,.5];[tf2,tf3]];// where, P in MN/m^2 and h in [kJ/kg]
+tf = interpln(Table_P_tf,.13);// saturation temperature, [C]
+
+// hence
+h2 = hg+(hg_150-hg)/(t2-tf)/(tf2-tf);// specific enthalpy at .13 MN/m^2 and 112 C, [kJ/kg]
+
+// now since process is throttling so h2=h1
+// and h1 = hf1+x1*hfg1, so
+x1 = (h2-hf1)/hfg1;// dryness fraction
+mprintf(' \n The dryness fraction of steam is = %f \n',x1);
+
+// There is a calculation mistake in book so answer is not matching
+
+// End
diff --git a/2705/CH4/EX4.16/Ex4_16.sce b/2705/CH4/EX4.16/Ex4_16.sce new file mode 100755 index 000000000..895917d3a --- /dev/null +++ b/2705/CH4/EX4.16/Ex4_16.sce @@ -0,0 +1,28 @@ +clear;
+clc;
+disp('Example 4.16');
+
+// aim : To determine
+// the minimum dryness fraction of steam
+
+// Given values
+P1 = 1.8;// testing pressure,[MN/m^2]
+P2 = .11;// pressure after throttling,[MN/m^2]
+
+// solution
+// from steam table
+// at .11 MN/m^2 steam is completely dry and specific enthalpy is
+hg = 2680;// [kJ/kg]
+
+// before throttling steam is wet, so specific enthalpy is=hf+x*hfg, where x is dryness fraction
+// from steam table
+hf = 885;// [kJ/kg]
+hfg = 1912;// [kJ/kg]
+
+// now for throttling process,specific enthalpy will same before and after
+// hence
+x = (hg-hf)/hfg;
+mprintf('\n The minimum dryness fraction of steam is x = %f \n',x);
+
+// End
+
diff --git a/2705/CH4/EX4.17/Ex4_17.sce b/2705/CH4/EX4.17/Ex4_17.sce new file mode 100755 index 000000000..b85b38646 --- /dev/null +++ b/2705/CH4/EX4.17/Ex4_17.sce @@ -0,0 +1,52 @@ +clear;
+clc;
+disp('Example 4.17');
+
+// aim : To determine the
+// (a) mass of steam in the vessel
+// (b) final dryness of the steam
+// (c) amount of heat transferrred during the cooling process
+
+// Given values
+V1 = .8;// [m^3]
+P1 = 360;// [kN/m^2]
+P2 = 200;// [kN/m^2]
+
+// solution
+
+// (a)
+// at 360 kN/m^2
+vg1 = .510;// [m^3]
+m = V1/vg1;// mass of steam,[kg]
+mprintf('\n (a) The mass of steam in the vessel is = %f kg\n',m);
+
+// (b)
+// at 200 kN/m^2
+vg2 = .885;// [m^3/kg]
+// the volume remains constant so
+x = vg1/vg2;// final dryness fraction
+mprintf('\n (b) The final dryness fraction of the steam is = %f \n',x);
+
+// (c)
+// at 360 kN/m^2
+h1 = 2732.9;// [kJ/kg]
+// hence
+u1 = h1-P1*vg1;// [kJ/kg]
+
+// at 200 kN/m^2
+hf = 504.7;// [kJ/kg]
+hfg=2201.6;//[kJ/kg]
+// hence
+h2 = hf+x*hfg;// [kJ/kg]
+// now
+u2 = h2-P2*vg1;// [kJ/kg]
+// so
+del_u = u2-u1;// [kJ/kg]
+// from the first law of thermodynamics del_U+W=Q,
+W = 0;// because volume is constant
+del_U = m*del_u;// [kJ]
+// hence
+Q = del_U;// [kJ]
+mprintf('\n (c) The amount of heat transferred during cooling process is = %f kJ \n',Q);
+
+// End
diff --git a/2705/CH4/EX4.18/Ex4_18.sce b/2705/CH4/EX4.18/Ex4_18.sce new file mode 100755 index 000000000..61a3ef637 --- /dev/null +++ b/2705/CH4/EX4.18/Ex4_18.sce @@ -0,0 +1,31 @@ +clear;
+clc;
+disp('Example 4.18');
+
+// aim : To determine
+// the heat received by the steam per kilogram
+
+// Given values
+// initial
+P1 = 4;// pressure, [MN/m^2]
+x1 = .95; // dryness fraction
+
+// final
+t2 = 350;// temperature,[C]
+
+// solution
+
+// from steam table, at 4 MN/m^2 and x1=.95
+hf = 1087.4;// [kJ/kg]
+hfg = 1712.9;// [kJ/kg]
+// hence
+h1 = hf+x1*hfg;// [kJ/kg]
+
+// since pressure is kept constant ant temperature is raised so at this condition
+h2 = 3095;// [kJ/kg]
+
+// so by energy balance
+Q = h2-h1;// Heat received,[kJ/kg]
+mprintf('\n The heat received by the steam is = %f kJ/kg \n',Q);
+
+// End
diff --git a/2705/CH4/EX4.19/Ex4_19.sce b/2705/CH4/EX4.19/Ex4_19.sce new file mode 100755 index 000000000..edc6f9d44 --- /dev/null +++ b/2705/CH4/EX4.19/Ex4_19.sce @@ -0,0 +1,50 @@ +clear;
+clc;
+disp('Example 4.19');
+
+// aim : To determine the condition of the steam after
+// (a) isothermal compression to half its initial volume,heat rejected
+// (b) hyperbolic compression to half its initial volume
+
+// Given values
+V1 = .3951;// initial volume,[m^3]
+P1 = 1.5;// initial pressure,[MN/m^2]
+
+// solution
+
+// (a)
+// from steam table, at 1.5 MN/m^2
+hf1 = 844.7;// [kJ/kg]
+hfg1 = 1945.2;// [kJ/kg]
+hg1 = 2789.9;// [kJ/kg]
+vg1 = .1317;// [m^3/kg]
+
+// calculation
+m = V1/vg1;// mass of steam,[kg]
+vg2b = vg1/2;// given,[m^3/kg](vg2b is actual specific volume before compression)
+x1 = vg2b/vg1;// dryness fraction
+h1 = m*(hf1+x1*hfg1);// [kJ]
+Q = m*x1*hfg1;// heat loss,[kJ]
+mprintf('\n (a) The Quantity of steam present is = %f kg \n',m);
+mprintf('\n Dryness fraction is = %f \n',x1);
+mprintf('\n The enthalpy is = %f kJ \n',h1);
+mprintf('\n The heat loss is = %f kJ \n',Q);
+
+// (b)
+V2 = V1/2;
+// Given compression is according to the law PV=Constant,so
+P2 = P1*V1/V2;// [MN/m^2]
+// from steam table at P2
+hf2 = 1008.4;// [kJ/kg]
+hfg2 = 1793.9;// [kJ/kg]
+hg2 = 2802.3;// [kJ/kg]
+vg2 = .0666;// [m^3/kg]
+
+// calculation
+x2 = vg2b/vg2;// dryness fraction
+h2 = m*(hf2+x2*hfg2);// [kJ]
+
+mprintf('\n (b) The dryness fraction is = %f \n',x2);
+mprintf('\n The enthalpy is = %f kJ\n',h2);
+
+// End
diff --git a/2705/CH4/EX4.2/Ex4_2.sce b/2705/CH4/EX4.2/Ex4_2.sce new file mode 100755 index 000000000..d3c8e64dd --- /dev/null +++ b/2705/CH4/EX4.2/Ex4_2.sce @@ -0,0 +1,42 @@ +clear;
+clc;
+disp('Example 4.2');
+
+// aim : To determine
+// saturation temperature and enthalpy
+
+// Given values
+P = 2.04;// pressure, [MN/m^2]
+
+// solution
+// since in the steam table values of enthalpy and saturation temperature at 2 and 2.1 MN?m^2 are given, so for knowing required values at given pressure,there is need to do interpolation
+
+// calculation of saturation temperature
+// from steam table
+Table_P_tf = [[2.1,2.0];[214.9,212.4]]; // P in [MN/m^2] and tf in [C]
+// using interpolation
+tf = interpln(Table_P_tf,2.04);// saturation temperature at given condition
+mprintf('\n The Saturation temperature is = %f C \n',tf);
+
+// calculation of specific liquid enthalpy
+// from steam table
+Table_P_hf = [[2.1,2.0];[920.0,908.6]];// P in [MN/m^2] and hf in [kJ/kg]
+// using interpolation
+hf = interpln(Table_P_hf,2.04); // enthalpy at given condition, [kJ/kg]
+mprintf('\n The Specific liquid enthalpy is = %f kJ/kg \n',hf);
+
+// calculation of specific enthalpy of evaporation
+// from steam table
+Table_P_hfg = [[2.1,2.0];[1878.2,1888.6]];// P in [MN/m^2] and hfg in [kJ/kg]
+// using interpolation
+hfg = interpln(Table_P_hfg,2.04); // enthalpy at given condition, [kJ/kg]
+mprintf('\n The Specific enthalpy of evaporation is = %f kJ/kg \n',hfg);
+
+// calculation of specific enthalpy of dry saturated steam
+// from steam table
+Table_P_hg = [[2.1,2.0];[2798.2,2797.2]];//P in [MN/m^2] and hg in [kJ/kg]
+// using interpolation
+hg = interpln(Table_P_hg,2.04); // enthalpy at given condition, [kJ/kg]
+mprintf('\n The Specific enthalpy of dry saturated steam is = %f kJ/kg \n',hg);
+
+// End
diff --git a/2705/CH4/EX4.20/Ex4_20.sce b/2705/CH4/EX4.20/Ex4_20.sce new file mode 100755 index 000000000..47eddb9ac --- /dev/null +++ b/2705/CH4/EX4.20/Ex4_20.sce @@ -0,0 +1,76 @@ +clear;
+clc;
+disp('Example 4.20');
+
+// aim : To determine the
+// (a) mass of steam
+// (b) work transfer
+// (c) change of internal energy
+// (d) heat exchange b/w the steam and surroundings
+
+// Given values
+P1 = 2.1;// initial pressure,[MN/m^2]
+x1 = .9;// dryness fraction
+V1 = .427;// initial volume,[m^3]
+P2 = .7;// final pressure,[MN/m^2]
+// Given process is polytropic with
+n = 1.25; // polytropic index
+
+// solution
+// from steam table
+
+// at 2.1 MN/m^2
+hf1 = 920.0;// [kJ/kg]
+hfg1=1878.2;// [kJ/kg]
+hg1=2798.2;// [kJ/kg]
+vg1 = .0949;// [m^3/kg]
+
+// and at .7 MN/m^2
+hf2 = 697.1;// [kJ/kg]
+hfg2 = 2064.9;// [kJ/kg]
+hg2 = 2762.0;// [kJ/kg]
+vg2 = .273;// [m^3/kg]
+
+// (a)
+v1 = x1*vg1;// [m^3/kg]
+m = V1/v1;// [kg]
+mprintf('\n (a) The mass of steam present is = %f kg\n',m);
+
+// (b)
+// for polytropic process
+v2 = v1*(P1/P2)^(1/n);// [m^3/kg]
+
+x2 = v2/vg2;// final dryness fraction
+// work transfer
+W = m*(P1*v1-P2*v2)*10^3/(n-1);// [kJ]
+mprintf('\n (b) The work transfer is = %f kJ\n',W);
+
+// (c)
+// initial
+h1 = hf1+x1*hfg1;// [kJ/kg]
+u1 = h1-P1*v1*10^3;// [kJ/kg]
+
+// final
+h2 = hf2+x2*hfg2;// [kJ/kg]
+u2 = h2-P2*v2*10^3;// [kJ/kg]
+
+del_U = m*(u2-u1);// [kJ]
+mprintf('\n (c) The change in internal energy is = %f kJ',del_U);
+if(del_U<0)
+ disp('since del_U<0,so this is loss of internal energy')
+else
+ disp('since del_U>0,so this is gain in internal energy')
+end
+
+// (d)
+Q = del_U+W;// [kJ]
+mprintf('\n (d) The heat exchange between the steam and surrounding is = %f kJ',Q);
+if(Q<0)
+ disp('since Q<0,so this is loss of heat energy to surrounding')
+else
+ disp('since Q>0,so this is gain in heat energy to the steam')
+end
+
+// there are minor vairations in the values reported in the book
+
+// End
diff --git a/2705/CH4/EX4.21/Ex4_21.sce b/2705/CH4/EX4.21/Ex4_21.sce new file mode 100755 index 000000000..6aafe47b0 --- /dev/null +++ b/2705/CH4/EX4.21/Ex4_21.sce @@ -0,0 +1,42 @@ +clear;
+clc;
+disp('Example 4.21');
+
+// aim : To determine the
+// (a) volume occupied by steam
+// (b)(1) final dryness fraction of steam
+// (2) Change of internal energy during expansion
+
+// (a)
+// Given values
+P1 = .85;// [mN/m^2]
+x1 = .97;
+
+// solution
+// from steam table, at .85 MN/m^2,
+vg1 = .2268;// [m^3/kg]
+// hence
+v1 = x1*vg1;// [m^3/kg]
+mprintf('\n (a) The volume occupied by 1 kg of steam is = %f m^3/kg\n',v1);
+
+// (b)(1)
+P2 = .17;// [MN/m^2]
+// since process is polytropic process with
+n = 1.13; // polytropic index
+// hence
+v2 = v1*(P1/P2)^(1/n);// [m^3/kg]
+
+// from steam table at .17 MN/m^2
+vg2 = 1.031;// [m^3/kg]
+// steam is wet so
+x2 = v2/vg2;// final dryness fraction
+mprintf('\n (b)(1) The final dryness fraction of the steam is = %f \n',x2);
+
+// (2)
+W = (P1*v1-P2*v2)*10^3/(n-1);// [kJ/kg]
+// since process is adiabatic, so
+del_u = -W;// [kJ/kg]
+mprintf('\n (2) The change in internal energy of the steam during expansion is = %f kJ/kg (This is a loss of internal energy)\n',del_u);
+// There are minor variation in the answer
+
+// End
diff --git a/2705/CH4/EX4.3/Ex4_3.sce b/2705/CH4/EX4.3/Ex4_3.sce new file mode 100755 index 000000000..7b6b2dd19 --- /dev/null +++ b/2705/CH4/EX4.3/Ex4_3.sce @@ -0,0 +1,30 @@ +clear;
+clc;
+disp('Example 4.3');
+
+// aim : To determine
+// the specific enthalpy
+
+// given values
+P = 2; // pressure ,[MN/m^2]
+t = 250; // Temperature, [C]
+cp = 2.0934; // average value of specific heat capacity, [kJ/kg K]
+
+// solution
+
+// looking up steam table it shows that at given pressure saturation temperature is 212.4 C,so
+tf = 212.4; // [C]
+// hence,
+Degree_of_superheat = t-tf;// [C]
+// from table at given temperature 250 C
+h = 2902; // specific enthalpy of steam at 250 C ,[kJ/kg]
+mprintf('\nThe specific enthalpy of steam at 2 MN/m^2 with temperature 250 C is = %f kJ/kg \n',h);
+
+// Also from steam table enthalpy at saturation temperature is
+hf = 2797.2 ;// [kJ/kg]
+// so enthalpy at given temperature is
+h = hf+cp*(t-tf);// [kJ/kg]
+
+mprintf('\n The specific enthalpy at given T and P by alternative path is = %f kJ/kg \n',h);
+
+// End
diff --git a/2705/CH4/EX4.4/Ex4_4.sce b/2705/CH4/EX4.4/Ex4_4.sce new file mode 100755 index 000000000..2af9a5594 --- /dev/null +++ b/2705/CH4/EX4.4/Ex4_4.sce @@ -0,0 +1,43 @@ +clear;
+clc;
+disp('Example 4.4');
+
+// aim : To determine
+// the specific enthalpy of steam
+
+// Given values
+P = 2.5;// pressure, [MN/m^2]
+t = 320; // temperature, [C]
+
+// solution
+// from steam table at given condition the saturation temperature of steam is 223.9 C, therefore steam is superheated
+tf = 223.9;// [C]
+
+// first let's calculate estimated enthalpy
+// again from steam table
+
+hg = 2800.9;// enthalpy at saturation temp, [kJ/kg]
+cp =2.0934;// specific heat capacity of steam,[kJ/kg K]
+
+// so enthalpy at given condition is
+h = hg+cp*(t-tf);// [kJ/kg]
+mprintf('\n The estimated specific enthalpy is = %f kJ/kg \n',h);
+
+// calculation of accurate specific enthalpy
+// we need double interpolation for this
+
+// first interpolation w.r.t. to temperature
+// At 2 MN/m^2
+Table_t_h = [[325,300];[3083,3025]];// where, t in [C] and h in [kJ/kg]
+h1 = interpln(Table_t_h,320); // [kJ/kg]
+
+// at 4 MN/m^2
+Table_t_h = [[325,300];[3031,2962]]; // t in [C] and h in [kJ/kg]
+h2 = interpln(Table_t_h,320); // [kJ/kg]
+
+// now interpolation w.r.t. pressure
+Table_P_h = [[4,2];[h2,h1]]; // where P in NM/m^2 and h1,h2 in kJ/kg
+h = interpln(Table_P_h,2.5);// [kJ/kg]
+mprintf('\n The accurate specific enthalpy of steam at pressure of 2.5 MN/m^2 and with a temperature 320 C is = %f kJ/kg \n',h);
+
+// End
diff --git a/2705/CH4/EX4.5/Ex4_5.sce b/2705/CH4/EX4.5/Ex4_5.sce new file mode 100755 index 000000000..c2c030046 --- /dev/null +++ b/2705/CH4/EX4.5/Ex4_5.sce @@ -0,0 +1,25 @@ +clear;
+clc;
+disp('Example 4.5');
+
+// aim : To determine
+// the specific enthalpy
+
+// Given values
+P = 70; // pressure, [kn/m^2]
+x = .85; // Dryness fraction
+
+// solution
+
+// from steam table, at given pressure
+hf = 376.8;// [kJ/kg]
+hfg = 2283.3;// [kJ/kg]
+
+// now using equation [2]
+h = hf+x*hfg;// specific enthalpy of wet steam,[kJ/kg]
+
+mprintf('\n The specific enthalpy of wet steam is = %f kJ/kg \n',h);
+
+// There is minor variation in the book's answer
+
+// End
diff --git a/2705/CH4/EX4.8/Ex4_8.sce b/2705/CH4/EX4.8/Ex4_8.sce new file mode 100755 index 000000000..7cfe99980 --- /dev/null +++ b/2705/CH4/EX4.8/Ex4_8.sce @@ -0,0 +1,20 @@ +clear;
+clc;
+disp('Example 4.8');
+
+// aim : To determine
+// the specific volume of wet steam
+
+// Given values
+P = 1.25; // pressure, [MN/m^2]
+x = .9; // dry fraction
+
+// solution
+// from steam table at given pressure
+vg = .1569;// [m^3/kg]
+// hence
+v = x*vg; // [m^3/kg]
+
+mprintf('\nThe specific volume of wet steam is = %f m^3/kg \n',v);
+
+// End
diff --git a/2705/CH4/EX4.9/Ex4_9.sce b/2705/CH4/EX4.9/Ex4_9.sce new file mode 100755 index 000000000..d9417bfea --- /dev/null +++ b/2705/CH4/EX4.9/Ex4_9.sce @@ -0,0 +1,21 @@ +clear;
+clc;
+disp('Example 4.9');
+
+// aim : To determine
+// the specific volume
+
+// Given values
+t = 325; // temperature, [C]
+P = 2; // pressure, [MN/m^2]
+
+// solution
+// from steam table at given t and P
+vf = .1321; // [m^3/kg]
+tf = 212.4; // saturation temperature, [C]
+
+mprintf('\n The specific volume of steam at pressure of 2 MN/m^2 and with temperature 325 C is = %f m^3/kg \n',vf);
+doh= t-tf; // degree of superheat, [C]
+mprintf('\n The degree of superheat is = %f C\n',doh);
+
+// End
diff --git a/2705/CH5/EX5.1/Ex5_1.sce b/2705/CH5/EX5.1/Ex5_1.sce new file mode 100755 index 000000000..dd8a53487 --- /dev/null +++ b/2705/CH5/EX5.1/Ex5_1.sce @@ -0,0 +1,23 @@ +clear;
+clc;
+disp('Example 5.1');
+
+// aim : To determine
+// new pressure exerted on the air and the difference in two mercury column level
+
+// Given values
+P1 = 765;// atmospheric pressure, [mmHg]
+V1 = 20000;// [mm^3]
+V2 = 17000;// [mm^3]
+
+// solution
+
+// using boyle's law P*V=constant
+// hence
+P2 = P1*V1/V2;// [mmHg]
+mprintf('\n The new pressure exerted on the air is = %f mmHg \n',P2);
+
+del_h = P2-P1;// difference in Height of mercury column level
+mprintf('\n The difference in the two mercury column level is = %f mm\n',del_h);
+
+// End
diff --git a/2705/CH5/EX5.10/Ex5_10.sce b/2705/CH5/EX5.10/Ex5_10.sce new file mode 100755 index 000000000..b5d45cd32 --- /dev/null +++ b/2705/CH5/EX5.10/Ex5_10.sce @@ -0,0 +1,27 @@ +clear;
+clc;
+disp('Example 5.10');
+
+// aim : To determine
+// the new temperature of the gas
+
+// Given values
+V1 = .015;// original volume,[m^3]
+T1 = 273+285;// original temperature,[K]
+V2 = .09;// final volume,[m^3]
+
+// solution
+// Given gas is following the law,P*V^1.35=constant
+// so process is polytropic with
+n = 1.35; // polytropic index
+
+// hence
+T2 = T1*(V1/V2)^(n-1);// final temperature, [K]
+
+t2 = T2-273;// [C]
+
+mprintf('\n The new temperature of the gas is = %f C \n',t2);
+
+// there is minor error in book's answer
+
+// End
diff --git a/2705/CH5/EX5.11/Ex5_11.sce b/2705/CH5/EX5.11/Ex5_11.sce new file mode 100755 index 000000000..42acb405c --- /dev/null +++ b/2705/CH5/EX5.11/Ex5_11.sce @@ -0,0 +1,40 @@ +clear;
+clc;
+disp('Example 5.11');
+
+// aim : To determine the
+// (a) original and final volume of the gas
+// (b) final pressure of the gas
+// (c) final temperature of the gas
+
+// Given values
+m = .675;// mass of the gas,[kg]
+P1 = 1.4;// original pressure,[MN/m^2]
+T1 = 273+280;// original temperature,[K]
+R = .287;//gas constant,[kJ/kg K]
+
+// solution
+
+// (a)
+// using characteristic equation, P1*V1=m*R*T1
+V1 = m*R*T1*10^-3/P1;// [m^3]
+// also Given
+V2 = 4*V1;// [m^3]
+mprintf('\n (a) The original volume of the gas is = %f m^3\n',V1);
+mprintf('\n and The final volume of the gas is = %f m^3\n',V2);
+
+// (b)
+// Given that gas is following the law P*V^1.3=constant
+// hence process is polytropic with
+n = 1.3; // polytropic index
+P2 = P1*(V1/V2)^n;// formula for polytropic process,[MN/m^2]
+mprintf('\n (b) The final pressure of the gas is = %f kN/m^2\n',P2*10^3);
+
+// (c)
+// since mass is constant so,using P*V/T=constant
+// hence
+T2 = P2*V2*T1/(P1*V1);// [K]
+t2 = T2-273;// [C]
+mprintf('\n (c) The final temperature of the gas is = %f C\n',t2);
+
+// End
diff --git a/2705/CH5/EX5.12/Ex5_12.sce b/2705/CH5/EX5.12/Ex5_12.sce new file mode 100755 index 000000000..e522db8a2 --- /dev/null +++ b/2705/CH5/EX5.12/Ex5_12.sce @@ -0,0 +1,57 @@ +clear;
+clc;
+disp('Example 5.12');
+
+// aim : T0 determine
+// (a) change in internal nergy of the air
+// (b) work done
+// (c) heat transfer
+
+// Given values
+m = .25;// mass, [kg]
+P1 = 140;// initial pressure, [kN/m^2]
+V1 = .15;// initial volume, [m^3]
+P2 = 1400;// final volume, [m^3]
+cp = 1.005;// [kJ/kg K]
+cv = .718;// [kJ/kg K]
+
+// solution
+
+// (a)
+// assuming ideal gas
+R = cp-cv;// [kJ/kg K]
+// also, P1*V1=m*R*T1,hence
+T1 = P1*V1/(m*R);// [K]
+
+// given that process is polytropic with
+n = 1.25; // polytropic index
+T2 = T1*(P2/P1)^((n-1)/n);// [K]
+
+// Hence, change in internal energy is,
+del_U = m*cv*(T2-T1);// [kJ]
+mprintf('\n (a) The change in internal energy of the air is del_U = %f kJ',del_U);
+if(del_U>0)
+ disp('since del_U>0, so it is gain of internal energy to the air')
+else
+ disp('since del_U<0, so it is gain of internal energy to the surrounding')
+end
+
+// (b)
+W = m*R*(T1-T2)/(n-1);// formula of work done for polytropic process,[kJ]
+mprintf('\n (b) The work done is W = %f kJ',W);
+if(W>0)
+ disp('since W>0, so the work is done by the air')
+else
+ disp('since W<0, so the work is done on the air')
+end
+
+// (c)
+Q = del_U+W;// using 1st law of thermodynamics,[kJ]
+mprintf('\n (c) The heat transfer is Q = %f kJ',Q);
+if(Q>0)
+ disp('since Q>0, so the heat is received by the air')
+else
+ disp('since Q<0, so the heat is rejected by the air')
+end
+
+// End
diff --git a/2705/CH5/EX5.13/Ex5_13.sce b/2705/CH5/EX5.13/Ex5_13.sce new file mode 100755 index 000000000..e2fc9c1b2 --- /dev/null +++ b/2705/CH5/EX5.13/Ex5_13.sce @@ -0,0 +1,35 @@ +clear;
+clc;
+disp('Example 5.13');
+
+// aim : To determine the
+// final volume, work done and the change in internal energy
+
+// Given values
+P1 = 700;// initial pressure,[kN/m^2]
+V1 = .015;// initial volume, [m^3]
+P2 = 140;// final pressure, [kN/m^2]
+cp = 1.046;// [kJ/kg K]
+cv = .752; // [kJ/kg K]
+
+// solution
+
+Gamma = cp/cv;
+// for adiabatic expansion, P*V^gamma=constant, so
+V2 = V1*(P1/P2)^(1/Gamma);// final volume, [m^3]
+mprintf('\n The final volume of the gas is V2 = %f m^3\n',V2);
+
+// work done
+W = (P1*V1-P2*V2)/(Gamma-1);// [kJ]
+mprintf('\n The work done by the gas is = %f kJ\n',W);
+
+// for adiabatic process
+del_U = -W;// [kJ]
+mprintf('\n The change of internal energy is = %f kJ',del_U);
+if(del_U>0)
+ disp('since del_U>0, so the the gain in internal energy of the gas ')
+else
+ disp('since del_U<0, so this is a loss of internal energy from the gas')
+end
+
+// End
diff --git a/2705/CH5/EX5.14/Ex5_14.sce b/2705/CH5/EX5.14/Ex5_14.sce new file mode 100755 index 000000000..25771ce9f --- /dev/null +++ b/2705/CH5/EX5.14/Ex5_14.sce @@ -0,0 +1,54 @@ +clear;
+clc;
+disp('Example 5.14');
+
+// aim : To determine the
+// (a)heat transfer
+// (b)change of internal energy
+// (c)mass of gas
+
+// Given values
+V1 = .4;// initial volume, [m^3]
+P1 = 100;// initial pressure, [kN/m^2]
+T1 = 273+20;// temperature, [K]
+P2 = 450;// final pressure,[kN/m^2]
+cp = 1.0;// [kJ/kg K]
+Gamma = 1.4; // heat capacity ratio
+
+// solution
+
+// (a)
+// for the isothermal compression,P*V=constant,so
+V2 = V1*P1/P2;// [m^3]
+W = P1*V1*log(P1/P2);// formula of workdone for isothermal process,[kJ]
+
+// for isothermal process, del_U=0;so
+Q = W;
+mprintf('\n (a) The heat transferred during compression is Q = %f kJ\n',Q);
+
+
+// (b)
+V3 = V1;
+// for adiabatic expansion
+// also
+
+P3 = P2*(V2/V3)^Gamma;// [kN/m^2]
+W = -(P3*V3-P2*V2)/(Gamma-1);// work done formula for adiabatic process,[kJ]
+// also, Q=0,so using Q=del_U+W
+del_U = -W;// [kJ]
+mprintf('\n (b) The change of the internal energy during the expansion is,del_U = %f kJ\n',del_U);
+
+// (c)
+// for ideal gas
+// cp-cv=R, and cp/cv=gamma, hence
+R = cp*(1-1/Gamma);// [kj/kg K]
+
+// now using ideal gas equation
+m = P1*V1/(R*T1);// mass of the gas,[kg]
+mprintf('\n (c) The mass of the gas is,m = %f kg\n',m);
+
+// There is calculation mistake in the book
+
+
+// End
+
diff --git a/2705/CH5/EX5.15/Ex5_15.sce b/2705/CH5/EX5.15/Ex5_15.sce new file mode 100755 index 000000000..e5ae9aa6a --- /dev/null +++ b/2705/CH5/EX5.15/Ex5_15.sce @@ -0,0 +1,35 @@ +clear;
+clc;
+disp('Example 5.15');
+
+// aim : To determine
+// the heat transferred and polytropic specific heat capacity
+
+// Given values
+P1 = 1;// initial pressure, [MN/m^2]
+V1 = .003;// initial volume, [m^3]
+P2 = .1;// final pressure,[MN/m^2]
+cv = .718;// [kJ/kg*K]
+Gamma=1.4;// heat capacity ratio
+
+// solution
+// Given process is polytropic with
+n = 1.3;// polytropic index
+// hence
+V2 = V1*(P1/P2)^(1/n);// final volume,[m^3]
+W = (P1*V1-P2*V2)*10^3/(n-1);// work done,[kJ]
+// so
+Q = (Gamma-n)*W/(Gamma-1);// heat transferred,[kJ]
+
+mprintf('\n The heat received or rejected by the gas during this process is Q = %f kJ',Q);
+if(Q>0)
+ disp('since Q>0, so heat is received by the gas')
+else
+ disp('since Q<0, so heat is rejected by the gas')
+end
+
+// now
+cn = cv*(Gamma-n)/(n-1);// polytropic specific heat capacity,[kJ/kg K]
+mprintf('\n The polytropic specific heat capacity is cn = %f kJ/kg K\n',cn);
+
+// End
diff --git a/2705/CH5/EX5.16/Ex5_16.sce b/2705/CH5/EX5.16/Ex5_16.sce new file mode 100755 index 000000000..37712f1ac --- /dev/null +++ b/2705/CH5/EX5.16/Ex5_16.sce @@ -0,0 +1,40 @@ +clear;
+clc;
+disp('Example 5.16');
+
+// aim : To determine the
+// (a) initial partial pressure of the steam and air
+// (b) final partial pressure of the steam and air
+// (c) total pressure in the container after heating
+
+// Given values
+T1 = 273+39;// initial temperature,[K]
+P1 = 100;// pressure, [MN/m^2]
+T2 = 273+120.2;// final temperature,[K]
+
+// solution
+
+// (a)
+// from the steam tables, the pressure of wet steam at 39 C is
+Pw1 = 7;// partial pressure of wet steam,[kN/m^2]
+// and by Dalton's law
+Pa1 = P1-Pw1;// initial pressure of air, [kN/m^2]
+
+mprintf('\n (a) The initial partial pressure of the steam is = %f kN/m^2',Pw1);
+mprintf('\n The initial partial pressure of the air is = %f kN/m^2\n',Pa1);
+
+// (b)
+// again from steam table, at 120.2 C the pressure of wet steam is
+Pw2 = 200;// [kN/m^2]
+
+// now since volume is constant so assuming air to be ideal gas so for air P/T=contant, hence
+Pa2 = Pa1*T2/T1 ;// [kN/m^2]
+
+mprintf(' \n(b) The final partial pressure of the steam is = %f kN/m^2',Pw2);
+mprintf('\n The final partial pressure of the air is = %f kN/m^2\n',Pa2);
+
+// (c)
+Pt = Pa2+Pw2;// using dalton's law, total pressure,[kN/m^2]
+mprintf('\n (c) The total pressure after heating is = %f kN/m^2\n',Pt);
+
+// End
diff --git a/2705/CH5/EX5.17/Ex5_17.sce b/2705/CH5/EX5.17/Ex5_17.sce new file mode 100755 index 000000000..187f6250a --- /dev/null +++ b/2705/CH5/EX5.17/Ex5_17.sce @@ -0,0 +1,40 @@ +clear;
+clc;
+disp('Example 5.17');
+
+// aim : To determine
+// the partial pressure of the air and steam, and the mass of the air
+
+// Given values
+P1 = 660;// vaccum gauge pressure on condenser [mmHg]
+P = 765;// atmospheric pressure, [mmHg]
+x = .8;// dryness fraction
+T = 273+41.5;// temperature,[K]
+ms_dot = 1500;// condense rate of steam,[kg/h]
+R = .29;// [kJ/kg]
+
+// solution
+Pa = (P-P1)*.1334;// absolute pressure,[kN/m^2]
+// from steam table, at 41.5 C partial pressure of steam is
+Ps = 8;// [kN/m^2]
+// by dalton's law, partial pressure of air is
+Pg = Pa-Ps;// [kN/m^2]
+
+mprintf('\n The partial pressure of the air in the condenser is = %f kN/m^2\n',Pg);
+mprintf('\n The partial pressure of the steam in the condenser is = %f kN/m^2\n',Ps);
+
+// also
+vg = 18.1;// [m^3/kg]
+// so
+V = x*vg;// [m^3/kg]
+// The air associated with 1 kg of the steam will occupiy this same volume
+// for air, Pg*V=m*R*T,so
+m = Pg*V/(R*T);// [kg/kg steam]
+// hence
+ma = m*ms_dot;// [kg/h]
+
+mprintf('\n The mass of air which will associated with this steam is = %f kg\n',ma);
+
+// There is misprint in book
+
+// End
diff --git a/2705/CH5/EX5.18/Ex5_18.sce b/2705/CH5/EX5.18/Ex5_18.sce new file mode 100755 index 000000000..3266c108e --- /dev/null +++ b/2705/CH5/EX5.18/Ex5_18.sce @@ -0,0 +1,41 @@ +clear;
+clc;
+disp('Example 5.18');
+
+// aim : To determine the
+// (a) final pressure
+// (b) final dryness fraction of the steam
+
+// Given values
+P1 = 130;// initial pressure, [kN/m^2]
+T1 = 273+75.9;// initial temperature, [K]
+x1 = .92;// initial dryness fraction
+T2 = 273+120.2;// final temperature, [K]
+
+// solution
+
+// (a)
+// from steam table, at 75.9 C
+Pws = 40;// partial pressure of wet steam[kN/m^2]
+Pa = P1-Pws;// partial pressure of air, [kN/m^2]
+vg = 3.99// specific volume of the wet steam, [m^3/kg]
+// hence
+V1 = x1*vg;// [m^3/kg]
+V2 = V1/5;// [m^3/kg]
+// for air, mass is constant so, Pa*V1/T1=P2*V2/T2,also given ,V1/V2=5,so
+P2 = Pa*V1*T2/(V2*T1);// final pressure,[kN/m^2]
+
+// now for steam at 120.2 C
+Ps = 200;// final partial pressure of steam,[kN/m^2]
+// so by dalton's law total pressure in cylindert is
+Pt = P2+Ps;// [kN/m^2]
+mprintf('\n (a) The final pressure in the cylinder is = %f kN/m^2\n',Pt);
+
+// (b)
+// from steam table at 200 kN/m^2
+vg = .885;// [m^3/kg]
+// hence
+x2 = V2/vg;// final dryness fraction of the steam
+mprintf('\n (b) The final dryness fraction of the steam is = %f\n ',x2);
+
+// End
diff --git a/2705/CH5/EX5.19/Ex5_19.sce b/2705/CH5/EX5.19/Ex5_19.sce new file mode 100755 index 000000000..830fd787f --- /dev/null +++ b/2705/CH5/EX5.19/Ex5_19.sce @@ -0,0 +1,39 @@ +clear;
+clc;
+disp('Example 5.19')
+
+// aim : To determine the
+// (a) Gamma,
+// (b) del_U
+
+// Given Values
+P1 = 1400;// [kN/m^2]
+P2 = 100;// [kN/m^2]
+P3 = 220;// [kN/m^2]
+T1 = 273+360;// [K]
+m = .23;// [kg]
+cp = 1.005;// [kJ/kg*K]
+
+// Solution
+T3 = T1;// since process 1-3 is isothermal
+
+// (a)
+// for process 1-3, P1*V1=P3*V3,so
+V3_by_V1 = P1/P3;
+// also process 1-2 is adiabatic,so P1*V1^(Gamma)=P2*V2^(Gamma),hence
+// and process process 2-3 is iso-choric so,V3=V2 and
+V2_by_V1 = V3_by_V1;
+// hence,
+Gamma = log(P1/P2)/log(P1/P3); // heat capacity ratio
+
+mprintf('\n (a) The value of adiabatic index Gamma is = %f\n',Gamma);
+
+// (b)
+cv = cp/Gamma;// [kJ/kg K]
+// for process 2-3,P3/T3=P2/T2,so
+T2 = P2*T3/P3;// [K]
+
+// now
+del_U = m*cv*(T2-T1);// [kJ]
+mprintf('\n (b) The change in internal energy during the adiabatic expansion is U2-U1 = %f kJ (This is loss of internal energy)\n',del_U);
+// End
diff --git a/2705/CH5/EX5.2/Ex5_2.sce b/2705/CH5/EX5.2/Ex5_2.sce new file mode 100755 index 000000000..3e80ae408 --- /dev/null +++ b/2705/CH5/EX5.2/Ex5_2.sce @@ -0,0 +1,20 @@ +clear;
+clc;
+disp('Example 5.2');
+
+// aim : To determine
+// the new volume
+
+// Given values
+P1 = 300;// original pressure,[kN/m^2]
+V1 = .14;// original volume,[m^3]
+
+P2 = 60;// new pressure after expansion,[kn/m^2]
+
+// solution
+// since temperature is constant so using boyle's law P*V=constant
+V2 = V1*P1/P2;// [m^3]
+
+mprintf('\n The new volume after expansion is = %f m^3\n',V2);
+
+// End
diff --git a/2705/CH5/EX5.20/Ex5_20.sce b/2705/CH5/EX5.20/Ex5_20.sce new file mode 100755 index 000000000..daf3343a7 --- /dev/null +++ b/2705/CH5/EX5.20/Ex5_20.sce @@ -0,0 +1,43 @@ +clear;
+clc;
+disp('Example 5.20');
+
+// aim : To determine
+// the mass of oxygen and heat transferred
+
+// Given values
+V1 = 300;// [L]
+P1 = 3.1;// [MN/m^2]
+T1 = 273+18;// [K]
+P2 = 1.7;// [MN/m^2]
+T2 = 273+15;// [K]
+Gamma = 1.4; // heat capacity ratio
+// density condition
+P = .101325;// [MN/m^2]
+T = 273;// [K]
+V = 1;// [m^3]
+m = 1.429;// [kg]
+
+// hence
+R = P*V*10^3/(m*T);// [kJ/kg*K]
+// since volume is constant
+V2 = V1;// [L]
+// for the initial conditions in the cylinder,P1*V1=m1*R*T1
+m1 = P1*V1/(R*T1);// [kg]
+
+// after some of the gas is used
+m2 = P2*V2/(R*T2);// [kg]
+// The mass of oxygen remaining in cylinder is m2 kg,so
+// Mass of oxygen used is
+m_used = m1-m2;// [kg]
+mprintf('\n The mass of oxygen used = %f kg\n',m_used);
+
+// for non-flow process,Q=del_U+W
+// volume is constant so no external work is done so,Q=del_U
+cv = R/(Gamma-1);// [kJ/kg*K]
+
+// heat transfer is
+Q = m2*cv*(T1-T2);// (kJ)
+mprintf('\n The amount of heat transferred through the cylinder wall is = %f kJ\n',Q);
+
+// End
diff --git a/2705/CH5/EX5.21/Ex5_21.sce b/2705/CH5/EX5.21/Ex5_21.sce new file mode 100755 index 000000000..a5cdcb432 --- /dev/null +++ b/2705/CH5/EX5.21/Ex5_21.sce @@ -0,0 +1,43 @@ +clear;
+clc;
+disp('Example 5.21');
+
+// aim : To determine the
+// (a) work transferred during the compression
+// (b) change in internal energy
+// (c) heat transferred during the compression
+
+// Given values
+V1 = .1;// initial volume, [m^3]
+P1 = 120;// initial pressure, [kN/m^2]
+P2 = 1200; // final pressure, [kN/m^2]
+T1 = 273+25;// initial temperature, [K]
+cv = .72;// [kJ/kg*K]
+R = .285;// [kJ/kg*K]
+
+// solution
+
+// (a)
+// given process is polytropic with
+n = 1.2; // polytropic index
+// hence
+V2 = V1*(P1/P2)^(1/n);// [m^3]
+W = (P1*V1-P2*V2)/(n-1);// workdone formula, [kJ]
+mprintf('\n (a) The work transferred during the compression is = %f kJ\n',W);
+
+// (b)
+// now mass is constant so,
+T2 = P2*V2*T1/(P1*V1);// [K]
+// using, P*V=m*R*T
+m = P1*V1/(R*T1);// [kg]
+
+// change in internal energy is
+del_U = m*cv*(T2-T1);// [kJ]
+mprintf('\n (b) The change in internal energy is = %f kJ\n',del_U);
+
+// (c)
+Q = del_U+W;// [kJ]
+mprintf('\n (c) The heat transferred during the compression is = %f kJ\n',Q);
+
+// End
+
diff --git a/2705/CH5/EX5.22/Ex5_22.sce b/2705/CH5/EX5.22/Ex5_22.sce new file mode 100755 index 000000000..756233f57 --- /dev/null +++ b/2705/CH5/EX5.22/Ex5_22.sce @@ -0,0 +1,36 @@ +clear;
+clc;
+disp('Example 5.22');
+
+// aim : To determine the
+// (a) new pressure of the air in the receiver
+// (b) specific enthalpy of air at 15 C
+
+// Given values
+V1 = .85;// [m^3]
+T1 = 15+273;// [K]
+P1 = 275;// pressure,[kN/m^2]
+m = 1.7;// [kg]
+cp = 1.005;// [kJ/kg*K]
+cv = .715;// [kJ/kg*K]
+
+// solution
+
+// (a)
+
+R = cp-cv;// [kJ/kg*K]
+// assuming m1 is original mass of the air, using P*V=m*R*T
+m1 = P1*V1/(R*T1);// [kg]
+m2 = m1+m;// [kg]
+// again using P*V=m*R*T
+// P2/P1=(m2*R*T2/V2)/(m1*R*T1/V1); and T1=T2,V1=V2,so
+P2 = P1*m2/m1;// [kN/m^2]
+mprintf('\n (a) The new pressure of the air in the receiver is = %f kN/m^2\n',P2);
+
+// (b)
+// for 1 kg of air, h2-h1=cp*(T1-T0)
+// and if 0 is chosen as the zero enthalpy, then
+h = cp*(T1-273);// [kJ/kg]
+mprintf('\n (b) The specific enthalpy of the air at 15 C is = %f kJ/kg\n',h);
+
+// End
diff --git a/2705/CH5/EX5.23/Ex5_23.sce b/2705/CH5/EX5.23/Ex5_23.sce new file mode 100755 index 000000000..69c2910b0 --- /dev/null +++ b/2705/CH5/EX5.23/Ex5_23.sce @@ -0,0 +1,47 @@ +clear;
+clc;
+disp('Example 5.23');
+
+// aim : T determine the
+// (a) characteristic gas constant of the gas
+// (b) cp,
+// (c) cv,
+// (d) del_u
+// (e) work transfer
+
+// Given values
+P = 1;// [bar]
+T1 = 273+15;// [K]
+m = .9;// [kg]
+T2 = 273+250;// [K]
+Q = 175;// heat transfer,[kJ]
+
+// solution
+
+// (a)
+// using, P*V=m*R*T, given,
+m_by_V = 1.875;
+// hence
+R = P*100/(T1*m_by_V);// [kJ/kg*K]
+mprintf('\n (a) The characteristic gas constant of the gas is R = %f kJ/kg K\n',R);
+
+// (b)
+// using, Q=m*cp*(T2-T1)
+cp = Q/(m*(T2-T1));// [kJ/kg K]
+mprintf('\n (b) The specific heat capacity of the gas at constant pressure cp = %f kJ/kg K\n',cp);
+
+// (c)
+// we have, cp-cv=R,so
+cv = cp-R;// [kJ/kg*K]
+mprintf('\n (c) The specific heat capacity of the gas at constant volume cv = %f kJ/kg K\n',cv);
+
+// (d)
+del_U = m*cv*(T2-T1);// [kJ]
+mprintf('\n (d) The change in internal energy is = %f kJ\n',del_U);
+
+// (e)
+// using, Q=del_U+W
+W = Q-del_U;// [kJ]
+mprintf('\n (e) The work transfer is W = %f kJ\n',W);
+
+// End
diff --git a/2705/CH5/EX5.24/Ex5_24.sce b/2705/CH5/EX5.24/Ex5_24.sce new file mode 100755 index 000000000..70324999b --- /dev/null +++ b/2705/CH5/EX5.24/Ex5_24.sce @@ -0,0 +1,42 @@ +clear;
+clc;
+disp('Example 5.24');
+
+// aim : To determine the
+// (a) work transfer,
+// (b)del_U and,
+// (c)heat transfer
+
+// Given values
+V1 = .15;// [m^3]
+P1 = 1200;// [kN/m^2]
+T1 = 273+120;// [K]
+P2 = 200;// [kN/m^2]
+cp = 1.006;//[kJ/kg K]
+cv = .717;// [kJ/kg K]
+
+// solution
+
+// (a)
+// Given, PV^1.32=constant, so it is polytropic process with
+n = 1.32;// polytropic index
+// hence
+V2 = V1*(P1/P2)^(1/n);// [m^3]
+// now, W
+W = (P1*V1-P2*V2)/(n-1);// [kJ]
+mprintf('\n (a) The work transfer is W = %f kJ\n',W);
+
+// (b)
+R = cp-cv;// [kJ/kg K]
+m = P1*V1/(R*T1);// gas law,[kg]
+// also for polytropic process
+T2 = T1*(P2/P1)^((n-1)/n);// [K]
+// now for gas,
+del_U = m*cv*(T2-T1);// [kJ]
+mprintf('\n (b) The change of internal energy is del_U = %f kJ\n',del_U);
+
+// (c)
+Q = del_U+W;// first law of thermodynamics,[kJ]
+mprintf('\n (c) The heat transfer Q = %f kJ\n',Q);
+
+// End
diff --git a/2705/CH5/EX5.26/Ex5_26.sce b/2705/CH5/EX5.26/Ex5_26.sce new file mode 100755 index 000000000..83f0cc59c --- /dev/null +++ b/2705/CH5/EX5.26/Ex5_26.sce @@ -0,0 +1,45 @@ +clear;
+clc;
+disp('Example 5.26');
+
+// aim : To determine
+// the volume of the pressure vessel and the volume of the gas before transfer
+
+// Given values
+
+P1 = 1400;// initial pressure,[kN/m^2]
+T1 = 273+85;// initial temperature,[K]
+
+P2 = 700;// final pressure,[kN/m^2]
+T2 = 273+60;// final temperature,[K]
+
+m = 2.7;// mass of the gas passes,[kg]
+cp = .88;// [kJ/kg]
+cv = .67;// [kJ/kg]
+
+// solution
+
+// steady flow equation is, u1+P1*V1+C1^2/2+Q=u2+P2*V2+C2^2/2+W [1],
+// given, there is no kinetic energy change and neglecting potential energy term
+W = 0;// no external work done
+// so final equation is,u1+P1*v1+Q=u2 [2]
+// also u2-u1=cv*(T2-T1)
+// hence Q=cv*(T2-T1)-P1*v1 [3]
+// and for unit mass P1*v1=R*T1=(cp-cv)*T1 [4]
+// so finally
+Q = cv*(T2-T1)-(cp-cv)*T1;// [kJ/kg]
+// so total heat transferred is
+Q = m*Q;// [kJ]
+
+// using eqn [4]
+v1 = (cp-cv)*T1/P1;// [m^3/kg]
+// Total volume is
+V1 = m*v1;// [m^3]
+
+// using ideal gas equation P1*V1/T1=P2*V2/T2
+V2 = P1*T2*V1/(P2*T1);// final volume,[m^3]
+
+mprintf('\n The volume of gas before transfer is = %f m^3\n',V1);
+mprintf('\n The volume of pressure vessel is = %f m^3\n',V2);
+
+// End
diff --git a/2705/CH5/EX5.3/Ex5_3.sce b/2705/CH5/EX5.3/Ex5_3.sce new file mode 100755 index 000000000..71188b43b --- /dev/null +++ b/2705/CH5/EX5.3/Ex5_3.sce @@ -0,0 +1,20 @@ +clear;
+clc;
+disp('Example 5.3');
+
+// aim : To determine
+// the new volume of the gas
+
+// Given values
+V1 = 10000;// [mm^3]
+T1 = 273+18;// [K]
+T2 = 273+85;// [K]
+
+// solution
+// since pressure exerted on the apparatus is constant so using charle's law V/T=constant
+// hence
+V2 = V1*T2/T1;// [mm^3]
+
+mprintf('\n The new volume of the gas trapped in the apparatus is = %f mm^3\n',V2);
+
+// End
diff --git a/2705/CH5/EX5.4/Ex5_4.sce b/2705/CH5/EX5.4/Ex5_4.sce new file mode 100755 index 000000000..954ced5f4 --- /dev/null +++ b/2705/CH5/EX5.4/Ex5_4.sce @@ -0,0 +1,20 @@ +clear;
+clc;
+disp('Example 5.4');
+
+// aim : To determine
+// the final temperature
+
+// Given values
+V1 = .2;// original volume,[m^3]
+T1 = 273+303;// original temperature, [K]
+V2 = .1;// final volume, [m^3]
+
+// solution
+// since pressure is constant, so using charle's law V/T=constant
+// hence
+T2 = T1*V2/V1;// [K]
+t2 = T2-273;// [C]
+mprintf('\n The final temperature of the gas is = %f C\n',t2);
+
+// End
diff --git a/2705/CH5/EX5.5/Ex5_5.sce b/2705/CH5/EX5.5/Ex5_5.sce new file mode 100755 index 000000000..894496057 --- /dev/null +++ b/2705/CH5/EX5.5/Ex5_5.sce @@ -0,0 +1,25 @@ +clear;
+clc;
+disp('Example 5.5');
+
+// aim : To determine
+// the new volume of the gas
+
+// Given values
+
+// initial codition
+P1 = 140;// [kN/m^2]
+V1 = .1;// [m^3]
+T1 = 273+25;// [K]
+
+// final condition
+P2 = 700;// [kN/m^2]
+T2 = 273+60;// [K]
+
+// by charasteristic equation, P1*V1/T1=P2*V2/T2
+
+V2=P1*V1*T2/(T1*P2);// final volume, [m^3]
+
+mprintf('\nThe new volume of the gas is = %f m^3\n',V2);
+
+// End
diff --git a/2705/CH5/EX5.6/Ex5_6.sce b/2705/CH5/EX5.6/Ex5_6.sce new file mode 100755 index 000000000..40f5fc559 --- /dev/null +++ b/2705/CH5/EX5.6/Ex5_6.sce @@ -0,0 +1,29 @@ +clear;
+clc;
+disp('Example 5.6');
+
+// aim : To determine
+// the mas of the gas and new temperature
+
+// Given values
+P1 = 350;// [kN/m^2]
+V1 = .03;// [m^3]
+T1 = 273+35;// [K]
+R = .29;// Gas constant,[kJ/kg K]
+
+// solution
+// using charasteristic equation, P*V=m*R*T
+m = P1*V1/(R*T1);// [Kg]
+mprintf('\n The mass of the gas present is = %f kg\n',m);
+
+// Now the gas is compressed
+P2 = 1050;// [kN/m^2]
+V2 = V1;
+// since mass of the gas is constant so using, P*V/T=constant
+// hence
+T2 = T1*P2/P1// [K]
+t2 = T2-273;// [C]
+
+mprintf('\n The new temperature of the gas is = %f C\n',t2);
+
+// End
diff --git a/2705/CH5/EX5.7/Ex5_7.sce b/2705/CH5/EX5.7/Ex5_7.sce new file mode 100755 index 000000000..85cf1c2f9 --- /dev/null +++ b/2705/CH5/EX5.7/Ex5_7.sce @@ -0,0 +1,28 @@ +clear;
+clc;
+disp('Example 5.7');
+
+// aim : To determine
+// the heat transferred to the gas and its final pressure
+
+// Given values
+m = 2;// masss of the gas, [kg]
+V1 = .7;// volume,[m^3]
+T1 = 273+15;// original temperature,[K]
+T2 = 273+135;// final temperature,[K]
+cv = .72;// specific heat capacity at constant volume,[kJ/kg K]
+R = .29;// gas law constant,[kJ/kg K]
+
+// solution
+Q = m*cv*(T2-T1);// Heat transferred at constant volume,[kJ]
+mprintf('\n The heat transferred to the gas is = %f kJ\n',Q);
+
+// Now,using P1*V1=m*R*T1
+P1 = m*R*T1/V1;// [kN/m^2]
+
+// since volume of the system is constant, so P1/T1=P2/T2
+// hence
+P2 = P1*T2/T1;// final pressure,[kN/m^2]
+mprintf('\n The final pressure of the gas is = %f kN/m^2 \n',P2);
+
+// End
diff --git a/2705/CH5/EX5.8/Ex5_8.sce b/2705/CH5/EX5.8/Ex5_8.sce new file mode 100755 index 000000000..b99a3fdae --- /dev/null +++ b/2705/CH5/EX5.8/Ex5_8.sce @@ -0,0 +1,33 @@ +clear;
+clc;
+disp('Example 5.8');
+
+// aim : To determine
+// the heat transferred from the gas and the work done on the gas
+
+// Given values
+P1 = 275;// pressure, [kN/m^2]
+V1 = .09;// volume,[m^3]
+T1 = 273+185;// initial temperature,[K]
+T2 = 273+15;// final temperature,[K]
+cp = 1.005;// specific heat capacity at constant pressure,[kJ/kg K]
+R = .29;// gas law constant,[kJ/kg K]
+
+// solution
+// using P1*V1=m*R*T1
+m = P1*V1/(R*T1);// mass of the gas
+
+// calculation of heat transfer
+Q = m*cp*(T2-T1);// Heat transferred at constant pressure,[kJ]
+mprintf('\n The heat transferred to the gas is = %f kJ\n',Q);
+
+// calculation of work done
+// Now,since pressure is constant so, V/T=constant
+// hence
+V2 = V1*T2/T1;// [m^3]
+
+W = P1*(V2-V1);// formula for work done at constant pressure,[kJ]
+mprintf('\n Work done on the gas during the process is = %f kJ\n',W);
+
+// End
+
diff --git a/2705/CH5/EX5.9/Ex5_9.sce b/2705/CH5/EX5.9/Ex5_9.sce new file mode 100755 index 000000000..016e3d2ee --- /dev/null +++ b/2705/CH5/EX5.9/Ex5_9.sce @@ -0,0 +1,22 @@ +clear;
+clc;
+disp('Example 5.9');
+
+// aim : To determine
+// the new pressure of the gas
+
+// Given values
+P1 = 300;// original pressure,[kN/m^2]
+T1 = 273+25;// original temperature,[K]
+T2 = 273+180;// final temperature,[K]
+
+// solution
+// since gas compressing according to the law,P*V^1.4=constant
+// so,for polytropic process,T1/T2=(P1/P2)^((n-1)/n),here n=1.4
+
+// hence
+P2 = P1*(T2/T1)^((1.4)/(1.4-1));// [kN/m^2]
+
+mprintf('\n The new pressure of the gas is = %f kN/m^2\n',P2);
+
+// End
diff --git a/2705/CH7/EX7.1/Ex7_1.sce b/2705/CH7/EX7.1/Ex7_1.sce new file mode 100755 index 000000000..3a5463218 --- /dev/null +++ b/2705/CH7/EX7.1/Ex7_1.sce @@ -0,0 +1,25 @@ +clear;
+clc;
+disp('Example 7.1');
+
+// aim : To determine
+// the specific enthalpy of water
+
+// Given values
+Tf = 273+100;// Temperature,[K]
+
+// solution
+// from steam table
+cpl = 4.187;// [kJ/kg K]
+// using equation [8]
+sf = cpl*log(Tf/273.16);// [kJ/kg*K]
+mprintf('\n The specific entropy of water is = %f kJ/kg K\n',sf);
+
+// using steam table
+sf = 1.307;// [kJ/kg K]
+mprintf('\n From table The accurate value of sf in this case is = %f kJ/kg K\n',sf);
+
+// There is small error in book's final value of sf
+
+
+// End
diff --git a/2705/CH7/EX7.2/Ex7_2.sce b/2705/CH7/EX7.2/Ex7_2.sce new file mode 100755 index 000000000..38d974b14 --- /dev/null +++ b/2705/CH7/EX7.2/Ex7_2.sce @@ -0,0 +1,33 @@ +
+clear;
+clc;
+disp('Example 7.2');
+
+// aim : To determine
+// the specific entropy
+
+// Given values
+P = 2;// pressure,[MN/m^2]
+x = .8;// dryness fraction
+
+// solution
+// from steam table at given pressure
+Tf = 485.4;// [K]
+cpl = 4.187;// [kJ/kg K]
+hfg = 1888.6;// [kJ/kg]
+
+// (a) finding entropy by calculation
+s = cpl*log(Tf/273.16)+x*hfg/Tf;// formula for entropy calculation
+
+mprintf('\n (a) The specific entropy of wet steam is = %f kJ/kg K\n',s);
+
+// (b) calculation of entropy using steam table
+// from steam table at given pressure
+sf = 2.447;// [kJ/kg K]
+sfg = 3.89;// [kJ/kg K]
+// hence
+s = sf+x*sfg;// [kJ/kg K]
+
+mprintf('\n (b) The specific entropy using steam table is = %f kJ/kg K\n',s);
+
+// End
diff --git a/2705/CH7/EX7.3/Ex7_3.sce b/2705/CH7/EX7.3/Ex7_3.sce new file mode 100755 index 000000000..21e0a7087 --- /dev/null +++ b/2705/CH7/EX7.3/Ex7_3.sce @@ -0,0 +1,30 @@ +clear;
+clc;
+disp('Example 7.3');
+
+// aim : To determine
+// the specific entropy of steam
+
+// Given values
+P = 1.5;//pressure,[MN/m^2]
+T = 273+300;//temperature,[K]
+
+// solution
+
+// (a)
+// from steam table
+cpl = 4.187;// [kJ/kg K]
+Tf = 471.3;// [K]
+hfg = 1946;// [kJ/kg]
+cpv = 2.093;// [kJ/kg K]
+
+// usung equation [2]
+s = cpl*log(Tf/273.15)+hfg/Tf+cpv*log(T/Tf);// [kJ/kg K]
+mprintf('\n (a) The specific entropy of steam is = %f kJ/kg K\n',s);
+
+// (b)
+// from steam tables
+s = 6.919;// [kJ/kg K]
+mprintf('\n (b) The accurate value of specific entropy from steam table is = %f kJ/kg K\n',s);
+
+// End
diff --git a/2705/CH7/EX7.4/Ex7_4.sce b/2705/CH7/EX7.4/Ex7_4.sce new file mode 100755 index 000000000..c908c859e --- /dev/null +++ b/2705/CH7/EX7.4/Ex7_4.sce @@ -0,0 +1,30 @@ +clear;
+clc;
+disp('Example 7.4');
+
+// aim : To determine
+// the dryness fraction of steam
+
+// Given values
+P1 = 2;// initial pressure, [MN/m^2]
+t = 350;// temperature, [C]
+P2 = .28;// final pressure, [MN/m^2]
+
+// solution
+// at 2 MN/m^2 and 350 C,steam is superheated because the saturation temperature is 212.4 C
+// From steam table
+s1 = 6.957;// [kJ/kg K]
+
+// for isentropic process
+s2 = s1;
+// also
+sf2 = 1.647;// [kJ/kg K]
+sfg2 = 5.368;// [kJ/kg K]
+
+// using
+// s2 = sf2+x2*sfg2, where x2 is dryness fraction of steam
+// hence
+x2 = (s2-sf2)/sfg2;
+mprintf('\n The final dryness fraction of steam is x2 = %f\n',x2);
+
+// End
diff --git a/2705/CH7/EX7.5/Ex7_5.sce b/2705/CH7/EX7.5/Ex7_5.sce new file mode 100755 index 000000000..53cec3d7a --- /dev/null +++ b/2705/CH7/EX7.5/Ex7_5.sce @@ -0,0 +1,53 @@ +clear;
+clc;
+disp('Example 7.5');
+
+// aim : To determine
+// the final condition of steam...
+// the change in specific entropy during hyperbolic process
+
+// Given values
+P1 = 2;// pressure, [MN/m^2]
+t = 250;// temperature, [C]
+P2 = .36;// pressure, [MN/m^2]
+P3 = .06;// pressure, [MN/m^2]
+
+// solution
+
+// (a)
+// from steam table
+s1 = 6.545;// [kJ/kg K]
+// at .36 MN/m^2
+sg = 6.930;// [kJ/kg*K]
+
+sf2 = 1.738;// [kJ/kg K]
+sfg2 = 5.192;// [kJ/kg K]
+vg2 = .510;// [m^3]
+
+// so after isentropic expansion, steam is wet
+// hence, s2=sf2+x2*sfg2, where x2 is dryness fraction
+// also
+s2 = s1;
+// so
+x2 = (s2-sf2)/sfg2;
+// and
+v2 = x2*vg2;// [m^3]
+
+// for hyperbolic process
+// P2*v2=P3*v3
+// hence
+v3 = P2*v2/P3;// [m^3]
+
+mprintf('\n (a) From steam table at .06 MN/m^2 steam is superheated and has temperature of 100 C with specific volume is = %f m^3/kg\n',v3);
+
+// (b)
+// at this condition
+s3 = 7.609;// [kJ/kg*K]
+// hence
+change_s23 = s3-sg;// change in specific entropy during the hyperblic process[kJ/kg*K]
+mprintf('\n (b) The change in specific entropy during the hyperbolic process is = %f kJ/kg K\n',change_s23);
+
+// In the book they have taken sg instead of s2 for part (b), so answer is not matching
+
+// End
+
diff --git a/2705/CH7/EX7.6/Ex7_6.sce b/2705/CH7/EX7.6/Ex7_6.sce new file mode 100755 index 000000000..b9e9a3beb --- /dev/null +++ b/2705/CH7/EX7.6/Ex7_6.sce @@ -0,0 +1,67 @@ +
+clear;
+clc;
+disp('Example 7.6');
+
+// aim : To determine the
+// (a) heat transfer during the expansion and
+// (b) work done durind the expansion
+
+// given values
+m = 4.5; // mass of steam,[kg]
+P1 = 3; // initial pressure,[MN/m^2]
+T1 = 300+273; // initial temperature,[K]
+
+P2 = .1; // final pressure,[MN/m^2]
+x2 = .96; // dryness fraction at final stage
+
+// solution
+// for state point 1,using steam table
+s1 = 6.541;// [kJ/kg/K]
+u1 = 2751;// [kJ/kg]
+
+ // for state point 2
+ sf2 = 1.303;// [kJ/kg/K]
+ sfg2 = 6.056;// [kJ/kg/k]
+ T2 = 273+99.6;// [K]
+ hf2 = 417;// [kJ/kg]
+ hfg2 = 2258;// [kJ/kg]
+ vg2 = 1.694;// [m^3/kg]
+
+ // hence
+ s2 = sf2+x2*sfg2;// [kJ/kg/k]
+ h2 = hf2+x2*hfg2;// [kJ/kg]
+ u2 = h2-P2*x2*vg2*10^3;// [kJ/kg]
+
+ // Diagram of example 7.6
+ x = [s1 s2];
+ y = [T1 T2];
+plot2d(x,y);
+ xtitle('Diagram for example 7.6(T vs s)');
+ xlabel('Entropy (kJ/kg K)');
+ ylabel('Temperature (K)');
+
+x = [s1,s1];
+y = [0,T1];
+plot2d(x,y);
+
+x = [s2,s2];
+y = [0,T2];
+plot2d(x,y);
+
+ // (a)
+ // Q_rev is area of T-s diagram
+ Q_rev = (T1+T2)/2*(s2-s1);// [kJ/kg]
+ // so total heat transfer is
+ Q_rev = m*Q_rev;// [kJ]
+
+ // (b)
+ del_u = u2-u1;// change in internal energy, [kJ/kg]
+ // using 1st law of thermodynamics
+ W = Q_rev-m*del_u;// [kJ]
+
+mprintf('\n (a) The heat transfer during the expansion is = %f kJ (received)\n',Q_rev);
+
+ mprintf('\n (b) The work done during the expansion is = %f kJ\n',W);
+
+ // End
diff --git a/2705/CH7/EX7.7/Ex7_7.sce b/2705/CH7/EX7.7/Ex7_7.sce new file mode 100755 index 000000000..9a68eddbd --- /dev/null +++ b/2705/CH7/EX7.7/Ex7_7.sce @@ -0,0 +1,45 @@ +
+clear;
+clc;
+disp('Example 7.7');
+
+// aim : To determine the
+// (a) change of entropy
+// (b) The approximate change of entropy obtained by dividing the heat transferred by the gas by the mean absolute temperature during the compression
+
+// Given values
+P1 = 140;// initial pressure,[kN/m^2]
+V1 = .14;// initial volume, [m^3]
+T1 = 273+25;// initial temperature,[K]
+ P2 = 1400;// final pressure [kN/m^2]
+ n = 1.25; // polytropic index
+ cp = 1.041;// [kJ/kg K]
+ cv = .743;// [kJ/kg K]
+
+ // solution
+ // (a)
+ R = cp-cv;// [kJ/kg/K]
+ // using ideal gas equation
+ m = P1*V1/(R*T1);// mass of gas,[kg]
+ // since gas is following law P*V^n=constant ,so
+ V2 = V1*(P1/P2)^(1/n);// [m^3]
+
+ // using eqn [9]
+ del_s = m*(cp*log(V2/V1)+cv*log(P2/P1));// [kJ/K]
+ mprintf('\n (a) The change of entropy is = %f kJ/K\n',del_s);
+
+ // (b)
+ W = (P1*V1-P2*V2)/(n-1);// polytropic work,[kJ]
+ Gamma = cp/cv;// heat capacity ratio
+ Q = (Gamma-n)/(Gamma-1)*W;// heat transferred,[kJ]
+
+ // Again using polytropic law
+ T2 = T1*(V1/V2)^(n-1);// final temperature, [K]
+ T_avg = (T1+T2)/2;// mean absolute temperature, [K]
+
+ // so approximate change in entropy is
+ del_s = Q/T_avg;// [kJ/K]
+
+ mprintf('\n (b) The approximate change of entropy obtained by dividing the heat transferred by the gas by the mean absolute temperature during the compression = %f kJ/K\n',del_s);
+
+ // End
diff --git a/2705/CH7/EX7.8/Ex7_8.sce b/2705/CH7/EX7.8/Ex7_8.sce new file mode 100755 index 000000000..711505b0c --- /dev/null +++ b/2705/CH7/EX7.8/Ex7_8.sce @@ -0,0 +1,39 @@ +clear;
+clc;
+disp('Example 7.8');
+
+// aim : To determine
+// the change of entropy
+
+// Given values
+m = .3;// [kg]
+P1 = 350;// [kN/m^2]
+T1 = 273+35;// [K]
+P2 = 700;// [kN/m^2]
+V3 = .2289;// [m^3]
+cp = 1.006;// [kJ/kg K]
+cv = .717;// [kJ/kg K]
+
+// solution
+// for constant volume process
+R = cp-cv;// [kJ/kg K]
+// using PV=mRT
+V1 = m*R*T1/P1;// [m^3]
+
+// for constant volume process P/T=constant,so
+T2 = T1*P2/P1;// [K]
+s21 = m*cv*log(P2/P1);// formula for entropy change for constant volume process
+mprintf('\n The change of entropy in constant volume process is = %f kJ/kg K\n',s21);
+
+// 'For the above part result given in the book is wrong
+
+V2 = V1;
+// for constant pressure process
+T3 = T2*V3/V2;// [K]
+s32 = m*cp*log(V3/V2);// [kJ/kg K]
+
+mprintf('\n The change of entropy in constant pressure process is = %f kJ/kg K\n',s32);
+
+// there is misprint in the book's result
+
+// End
diff --git a/2705/CH7/EX7.9/Ex7_9.sce b/2705/CH7/EX7.9/Ex7_9.sce new file mode 100755 index 000000000..05f58353b --- /dev/null +++ b/2705/CH7/EX7.9/Ex7_9.sce @@ -0,0 +1,21 @@ +clear;
+clc;
+disp('Example 7.9');
+
+// aim : To determine
+// the change of entropy
+
+// Given values
+P1 = 700;// initial pressure, [kN/m^2]
+T1 = 273+150;// Temperature ,[K]
+V1 = .014;// initial volume, [m^3]
+V2 = .084;// final volume, [m^3]
+
+// solution
+// since process is isothermal so
+T2 = T1;
+// and using fig.7.10
+del_s = P1*V1*log(V2/V1)/T1 ;// [kJ/K]
+mprintf('\n The change of entropy is = %f kJ/kg K\n',del_s);
+
+// End
diff --git a/2705/CH8/EX8.1/Ex8_1.sce b/2705/CH8/EX8.1/Ex8_1.sce new file mode 100755 index 000000000..dc5881db5 --- /dev/null +++ b/2705/CH8/EX8.1/Ex8_1.sce @@ -0,0 +1,24 @@ +
+clear;
+clc;
+disp('Example 8.1');
+
+// aim : To determine
+// the stoichiometric mass of air required to burn 1 kg the fuel
+
+// Given values
+C = .72;// mass fraction of C; [kg/kg]
+H2 = .20;// mass fraction of H2;, [kg/kg]
+O2 = .08;// mass fraction of O2, [kg/kg]
+aO2=.232;// composition of oxygen in air
+
+// solution
+// for 1kg of fuel
+mO2 = 8/3*C+8*H2-O2;// mass of O2, [kg]
+
+// hence stoichiometric mass of O2 required is
+msO2 = mO2/aO2;// [kg]
+
+mprintf('\n The stoichiometric mass of air required to burn 1 kg the fuel should be = %f kg\n',msO2);
+
+// End
diff --git a/2705/CH8/EX8.10/Ex8_10.sce b/2705/CH8/EX8.10/Ex8_10.sce new file mode 100755 index 000000000..079878869 --- /dev/null +++ b/2705/CH8/EX8.10/Ex8_10.sce @@ -0,0 +1,44 @@ +clear;
+clc;
+disp('Example 8.10');
+
+// aim : To determine
+// volumetric composition of the products of combustion
+
+// given values
+C = .86;// mass composition of carbon
+H = .14;// mass composition of hydrogen
+Ea = .20;// excess air for combustion
+O2 = .23;// mass composition of O2 in air
+
+MCO2 = 44;// moleculer mass of CO2
+MH2O = 18;// moleculer mass of H2O
+MO2 = 32;// moleculer mass of O2
+MN2 = 28;// moleculer mass of N2,
+
+
+// solution
+sO2 = (8/3*C+8*H);// stoichiometric O2 required, [kg/kg petrol]
+sair = sO2/O2;// stoichiometric air required, [kg/kg petrol]
+// for one kg petrol
+mCO2 = 11/3*C;// mass of CO2,[kg]
+mH2O = 9*H;// mass of H2O, [kg]
+mO2 = Ea*sO2;// mass of O2, [kg]
+mN2 = 14.84*(1+Ea)*(1-O2);// mass of N2, [kg]
+
+mt = mCO2+mH2O+mO2+mN2;// total mass, [kg]
+// percentage mass composition
+x1 = mCO2/mt*100;// mass composition of CO2
+x2 = mH2O/mt*100;// mass composition of H2O
+x3 = mO2/mt*100;// mass composition of O2
+x4 = mN2/mt*100;// mass composition of N2
+
+vt = x1/MCO2+x2/MH2O+x3/MO2+x4/MN2;// total volume of petrol
+v1 = x1/MCO2/vt*100;// %age composition of CO2 by volume
+v2 = x2/MH2O/vt*100;// %age composition of H2O by volume
+v3 = x3/MO2/vt*100;// %age composition of O2 by volume
+v4 = x4/MN2/vt*100;// %age composition of N2 by volume
+
+mprintf('\nThe percentage composition of CO2 by volume is = %f\n,\nThe percentage composition of H2O by volume is = %f\n,\nThe percentage composition of O2 by volume is = %f\n,\nThe percentage composition of N2 by volume is = %f\n',v1,v2,v3,v4);
+
+// End
diff --git a/2705/CH8/EX8.11/Ex8_11.sce b/2705/CH8/EX8.11/Ex8_11.sce new file mode 100755 index 000000000..f9ee92977 --- /dev/null +++ b/2705/CH8/EX8.11/Ex8_11.sce @@ -0,0 +1,33 @@ +clear;
+clc;
+disp('Example 8.11');
+
+// aim : To determine
+// the energy carried away by the dry flue gas/kg of fuel burned
+
+// given values
+C = .78;// mass composition of carbon
+H2 = .06;// mass composition of hydrogen
+O2 = .09;// mass composition of oxygen
+Ash = .07;// mass composition of ash
+Ea = .50;// excess air for combustion
+aO2 = .23;// mass composition of O2 in air
+Tb = 273+20;// boiler house temperature, [K]
+Tf = 273+320;// flue gas temperature, [K]
+c = 1.006;// specific heat capacity of dry flue gas, [kJ/kg K]
+
+// solution
+// for one kg of fuel
+sO2 = (8/3*C+8*H2);// stoichiometric O2 required, [kg/kg fuel]
+sO2a = sO2-O2;// stoichiometric O2 required from air, [kg/kg fuel]
+sair = sO2a/aO2;// stoichiometric air required, [kg/kg fuel]
+ma = sair*(1+Ea);// actual air supplied/kg of fuel, [kg]
+// total mass of flue gas/kg fuel is
+mf = ma+1;// [kg]
+mH2 = 9*H2;//H2 produced, [kg]
+// hence, mass of dry flue gas/kg coall is
+m = mf-mH2;// [kg]
+Q = m*c*(Tf-Tb);// energy carried away by flue gas, [kJ]
+mprintf('\n The energy carried away by the dry flue gas/kg is = %f kg\n',Q);
+
+// End
diff --git a/2705/CH8/EX8.12/Ex8_12.sce b/2705/CH8/EX8.12/Ex8_12.sce new file mode 100755 index 000000000..ec6dd7d76 --- /dev/null +++ b/2705/CH8/EX8.12/Ex8_12.sce @@ -0,0 +1,49 @@ +clear;
+clc;
+disp('Example 8.12');
+
+// aim : To determine
+// (a) the stoichiometric volume of air for the complete combustion of 1 m^3
+// (b) the percentage volumetric analysis of the products of combustion
+
+// given values
+N2 = .018;// volumetric composition of N2
+CH4 = .94;// volumetric composition of CH4
+C2H6 = .035;// volumetric composition of C2H6
+C3H8 = .007;// volumetric composition of C3H8
+aO2 = .21;// O2 composition in air
+
+// solution
+// (a)
+// for CH4
+// CH4 +2 O2= CO2 + 2 H2O
+sva1 = 2/aO2;// stoichiometric volume of air, [m^3/m^3 CH4]
+svn1 = sva1*(1-aO2);// stoichiometric volume of nitrogen in the air, [m^3/m^3 CH4]
+
+// for C2H6
+// 2 C2H6 +7 O2= 4 CO2 + 6 H2O
+sva2 = 7/2/aO2;// stoichiometric volume of air, [m^3/m^3 C2H6]
+svn2 = sva2*(1-aO2);// stoichiometric volume of nitrogen in the air, [m^3/m^3 C2H6]
+
+// for C3H8
+// C3H8 +5 O2=3 CO2 + 4 H2O
+sva3 = 5/aO2;// stoichiometric volume of air, [m^3/m^3 C3H8]
+svn3 = sva3*(1-aO2);// stoichiometric volume of nitrogen in the air, [m^3/m^3 C3H8]
+
+Sva = CH4*sva1+C2H6*sva2+C3H8*sva3;// stoichiometric volume of air required, [m^3/m^3 gas]
+mprintf('\n (a) The stoichiometric volume of air for the complete combustion = %f m^3m^3 gas\n',Sva);
+
+// (b)
+// for one m^3 of natural gas
+vCO2 = CH4*1+C2H6*2+C3H8*3;// volume of CO2 produced, [m^3]
+vH2O = CH4*2+C2H6*3+C3H8*4;// volume of H2O produced, [m^3]
+vN2 = CH4*svn1+C2H6*svn2+C3H8*svn3+N2;// volume of N2 produced, [m^3]
+
+vg = vCO2+vH2O+vN2;// total volume of gas, [m^3]
+x1 = vCO2/vg*100;// volume percentage of CO2 produced
+x2 = vH2O/vg*100;// volume percentage of H2O produced
+x3 = vN2/vg*100;// volume percentage of N2 produced
+
+mprintf('\n (b) The percentage volumetric composition of CO2 in produced is = %f\n,\n The percentage volumetric composition of H2O in produced is = %f\n,\n The percentage volumetric composition of N2 in produced is = %f\n',x1,x2,x3);
+
+// End
diff --git a/2705/CH8/EX8.13/Ex8_13.sce b/2705/CH8/EX8.13/Ex8_13.sce new file mode 100755 index 000000000..87f8573ec --- /dev/null +++ b/2705/CH8/EX8.13/Ex8_13.sce @@ -0,0 +1,46 @@ +clear;
+clc;
+disp('Example 8.13');
+
+// aim : To determine
+// (a) the volume of air taken by the fan
+// (b) the percentage composition of dry flue gas
+
+// gien values
+C = .82;// mass composition of carbon
+H = .08;// mass composition of hydrogen
+ O = .03;// mass composition of oxygen
+ A = .07;// mass composition of ash
+mc = .19;// coal uses, [kg/s]
+ ea = .3;// percentage excess air of oxygen in the air required for combustion
+Oa = .23;// percentage of oxygen by mass in the air
+
+ // solution
+ // (a)
+ P = 100;// air pressure, [kN/m^2]
+ T = 18+273;// air temperature, [K]
+ R = .287;// [kJ/kg K]
+ // basis one kg coal
+ sO2 = 8/3*C+8*H;// stoichiometric O2 required, [kg]
+ aO2 = sO2-.03;// actual O2 required, [kg]
+tO2 = aO2/Oa;// theoretical O2 required, [kg]
+Aa = tO2*(1+ea);// actual air supplied, [kg]
+m = Aa*mc;// Air supplied, [kg/s]
+
+// now using P*V=m*R*T
+V = m*R*T/P;// volume of air taken ,[m^3/s]
+mprintf('\n (a) Volume of air taken by fan is = %f m^3/s\n',V);
+
+// (b)
+mCO2 = 11/3*C;// mass of CO2 produced, [kg]
+mO2 = aO2*.3;// mass of O2 produces, [kg]
+mN2 = Aa*.77;// mass of N2 produced, [[kg]
+mt = mCO2+mO2+mN2;// total mass, [kg]
+
+mprintf('\n (b) Percentage mass composition of CO2 is = %f percent \n',mCO2/mt*100);
+mprintf('\n Percentage mass composition of O2 is = %f percent\n',mO2/mt*100)
+mprintf('\n Percentage mass composition of N2 is = %f percent \n',mN2/mt*100)
+
+
+
+// End
diff --git a/2705/CH8/EX8.14/Ex8_14.sce b/2705/CH8/EX8.14/Ex8_14.sce new file mode 100755 index 000000000..a93839efd --- /dev/null +++ b/2705/CH8/EX8.14/Ex8_14.sce @@ -0,0 +1,40 @@ +clear;
+clc;
+disp('Example 8.14');
+
+// aim : To determine
+// (a) the mass of fuel used per cycle
+// (b) the actual mass of air taken in per cycle
+// (c) the volume of air taken in per cycle
+
+// given values
+W = 15;// work done, [kJ/s]
+N = 5;// speed, [rev/s]
+C = .84;// mass composition of carbon
+H = .16;// mass composition of hydrogen
+ea = 1;// percentage excess air supplied
+CV = 45000;// calorificvalue of fuel, [kJ/kg]
+n_the = .3;// thermal efficiency
+P = 100;// pressuer, [kN/m^2]
+T = 273+15;// temperature, [K]
+R = .29;// gas constant, [kJ/kg K]
+
+// solution
+// (a)
+E = W*2/N/n_the;// energy supplied, [kJ/cycle]
+mf = E/CV;// mass of fuell used, [kg]
+mprintf('\n (a) Mass of fuel used per cycle is = %f g\n',mf*10^3);
+
+// (b)
+// basis 1 kg fuel
+mO2 = C*8/3+8*H;// mass of O2 requirea, [kg]
+smO2 = mO2/.23;// stoichiometric mass of air, [kg]
+ma = smO2*(1+ea);// actual mass of air supplied, [kg]
+m = ma*mf;// mass of air supplied, [kg/cycle]
+mprintf('\n (b) The mass of air supplied per cycle is = %f kg\n',m);
+
+// (c)
+V = m*R*T/P;// volume of air, [m^3]
+mprintf('\n (c) The volume of air taken in per cycle is = %f m^3\n',V);
+
+// End
diff --git a/2705/CH8/EX8.15/Ex8_15.sce b/2705/CH8/EX8.15/Ex8_15.sce new file mode 100755 index 000000000..a4adab52d --- /dev/null +++ b/2705/CH8/EX8.15/Ex8_15.sce @@ -0,0 +1,70 @@ +clear;
+clc;
+disp('Example 8.15');
+
+// aim : To determine
+// (a) the mass of coal used per hour
+// (b) the mass of air used per hour
+// (c) the percentage analysis of the flue gases by mass
+
+// given values
+m = 900;// mass of steam boiler generate/h, [kg]
+x = .96;// steam dryness fraction
+P = 1400;// steam pressure, [kN/m^2]
+Tf = 52;// feed water temperature, [C]
+BE = .71;// boiler efficiency
+CV = 33000;// calorific value of coal, [kJkg[
+ea = .22;// excess air supply
+aO2 = .23;// oxygen composition in air
+c = 4.187;// specific heat capacity of water, [kJ/kg K]
+
+// coal composition
+C = .83;// mass composition of carbon
+H2 = .05;// mass composition of hydrogen
+O2 = .03;// mass composition of oxygen
+ash = .09;// mass composition of ash
+
+// solution
+// from steam table at pressure P
+hf = 830.1;// specific enthalpy, [kJ/kg]
+hfg = 1957.1;// specific enthalpy, [kJ/kg]
+hg = 2728.8;// specific enthalpy, [kJ/kg]
+
+// (a)
+h = hf+x*hfg;// specific enthalpy of steam generated by boiler, [kJ/kg]
+hfw = c*Tf;// specific enthalpy of feed water, [kJ/kg]
+Q = m*(h-hfw);// energy to steam/h, [kJ]
+Qf = Q/BE;// energy required from fuel/h, [kJ]
+mc = Qf/CV;// mass of coal/h,[kg]
+mprintf('\n (a) The mass of coal used per hour is = %f kg\n',mc);
+
+// (b)
+// for one kg coal
+mO2 = 8/3*C+8*H2+-O2;// actual mass of O2 required, [kg]
+mta = mO2/aO2;// theoretical mass of air, [kg]
+ma = mta*(1+ea);// mass of air supplied, [kg]
+mas = ma*mc;// mass of air supplied/h, [kg]
+mprintf('\n (b) The mass of air supplied per hour is = %f kg\n',mas);
+
+
+// (c)
+// for one kg coal
+mCO2 = 11/3*C;// mass of CO2 produced, [kg]
+mH2O = 9*H2;// mass of H2O produced, [kg]
+mO2 = mO2*ea;// mass of excess O2 in flue gas, [kg]
+mN2 = ma*(1-aO2);// mass of N2 in flue gas, [kg]
+
+mt = mCO2+mH2O+mO2+mN2;// total mass of gas
+x1 = mCO2/mt*100;// mass percentage composition of CO2
+x2 = mH2O/mt*100;// mass percentage composition of H2O
+x3 = mO2/mt*100;// mass percentage composition of O2
+x4 = mN2/mt*100;// mass percentage composition of N2
+
+mprintf('\n (c) The mass percentage composition of CO2 = %f,\n The mass percentage composition of H2O = %f,\n The mass percentage composition of O2 = %f,\n The mass percentage composition of N2 = %f',x1,x2,x3,x4);
+
+// mass of coal taken in part (b) is wrong so answer is not matching
+
+// End
+
+
+
diff --git a/2705/CH8/EX8.16/Ex8_16.sce b/2705/CH8/EX8.16/Ex8_16.sce new file mode 100755 index 000000000..5e1808b5d --- /dev/null +++ b/2705/CH8/EX8.16/Ex8_16.sce @@ -0,0 +1,40 @@ +clear;
+clc;
+disp('Example 8.16');
+
+// aim : To determine
+// (a) volume of gas
+// (b) (1) the average molecular mass of air
+// (2) the value of R
+// (3) the mass of 1 m^3 of air at STP
+
+// given values
+n = 1;// moles of gas, [kmol]
+P = 101.32;// standard pressure, [kN/m^2]
+T = 273;// gas tempearture, [K]
+
+O2 = 21;// percentage volume composition of oxygen in air
+N2 = 79;// percentage volume composition of nitrogen in air
+R = 8.3143;// molar gas constant, [kJ/kg K]
+mO2 = 32;// moleculer mass of O2
+mN2 = 28;// moleculer mass of N2
+
+// solution
+// (a)
+V = n*R*T/P;// volume of gas, [m^3]
+mprintf('\n (a) The volume of the gas is = %f m^3\n',V);
+
+// (b)
+//(1)
+Mav = (O2*mO2+N2*mN2)/(O2+N2);// average moleculer mass of air
+mprintf('\n (b)(1) The average moleculer mass of air is = %f g/mol\n',Mav);
+
+// (2)
+Rav = R/Mav;// characteristic gas constant, [kJ/kg k]
+mprintf('\n (2) The value of R is = %f kJ/kg K\n',Rav);
+
+// (3)
+rho = Mav/V;// density of air, [kg/m^3]
+mprintf('\n (3) The mass of one cubic metre of air at STP is = %f kg/m^3\n',rho);
+
+// End
diff --git a/2705/CH8/EX8.17/Ex8_17.sce b/2705/CH8/EX8.17/Ex8_17.sce new file mode 100755 index 000000000..d1099ee95 --- /dev/null +++ b/2705/CH8/EX8.17/Ex8_17.sce @@ -0,0 +1,48 @@ +clear;
+clc;
+disp('Example 8.17');
+
+// aim : To determine
+// (a) the partial pressure of each gas in the vessel
+// (b) the volume of the vessel
+// (c) the total pressure in the gas when temperature is raised to228 C
+
+// given values
+MO2 = 8;// mass of O2, [kg]
+MN2 = 7;// mass of N2, [kg]
+MCO2 = 22;// mass of CO2, [kg]
+
+P = 416;// total pressure in the vessel, [kN/m^2]
+T = 273+60;// vessel temperature, [K]
+R = 8.3143;// gas constant, [kJ/kmol K]
+
+mO2 = 32;// molculer mass of O2
+mN2 = 28;// molculer mass of N2
+mCO2 = 44;// molculer mass of CO2
+
+// solution
+// (a)
+n1 = MO2/mO2;// moles of O2, [kmol]
+n2 = MN2/mN2;// moles of N2, [kmol]
+n3 = MCO2/mCO2;// moles of CO2, [kmol]
+
+n = n1+n2+n3;// total moles in the vessel, [kmol]
+// since,Partial pressure is proportinal, so
+P1 = n1*P/n;// partial pressure of O2, [kN/m^2]
+P2 = n2*P/n;// partial pressure of N2, [kN/m^2]
+P3 = n3*P/n;// partial pressure of CO2, [kN/m^2]
+
+mprintf('\n (a)The partial pressure of O2 is = %f kN/m^2,\n, The partial pressure of N2 is = %f kN/m^2,\n The partial pressure of CO2 is = %f kN/m^2,\n',P1,P2,P3);
+
+// (b)
+// assuming ideal gas
+V = n*R*T/P;// volume of the container, [m^3]
+mprintf('\n (b) The volume of the container is = %f m^3\n',V);
+
+// (c)
+T2 = 273+228;// raised vessel temperature, [K]
+// so volume of vessel will constant , P/T=constant
+P2 = P*T2/T;// new pressure in the vessel , [kn/m62]
+mprintf('\n (c) The new total pressure in the vessel is = %f kN/m^2\n',P2);
+
+// End
diff --git a/2705/CH8/EX8.18/Ex8_18.sce b/2705/CH8/EX8.18/Ex8_18.sce new file mode 100755 index 000000000..c0961970a --- /dev/null +++ b/2705/CH8/EX8.18/Ex8_18.sce @@ -0,0 +1,65 @@ +clear;
+clc;
+disp('Example 8.18');
+
+// aim : To determine
+// the actual mass of air supplied/kg coal
+// the velocity of flue gas
+
+// given values
+mc = 635;// mass of coal burn/h, [kg]
+ea = .25;// excess air required
+C = .84;// mass composition of carbon
+H2 = .04;// mass composition of hydrogen
+O2 = .05;// mass composition of oxygen
+ash = 1-(C+H2+O2);// mass composition of ash
+
+P1 = 101.3;// pressure, [kJn/m^2]
+T1 = 273;// temperature, [K]
+V1 = 22.4;// volume, [m^3]
+
+T2 = 273+344;// gas temperature, [K]
+P2 = 100;// gas pressure, [kN/m^2]
+A = 1.1;// cross section area, [m^2]
+aO2 = .23;// composition of O2 in air
+
+mCO2 = 44;// moleculer mass of carbon
+mH2O = 18;// molecular mass of hydrogen
+mO2 = 32;// moleculer mas of oxygen
+mN2 = 28;// moleculer mass of nitrogen
+
+// solution
+mtO2 = 8/3*C+8*H2-O2;// theoretical O2 required/kg coal, [kg]
+msa= mtO2/aO2;// stoichiometric mass of air supplied/kg coal, [kg]
+mas = msa*(1+ea);// actual mass of air supplied/kg coal, [kg]
+
+m1 = 11/3*C;// mass of CO2/kg coal produced, [kg]
+m2 = 9*H2;// mass of H2/kg coal produced, [kg]
+m3 = mtO2*ea;// mass of O2/kg coal produced, [kg]
+m4 = mas*(1-aO2);// mass of N2/kg coal produced, [kg]
+
+mt = m1+m2+m3+m4;// total mass, [kg]
+x1 = m1/mt*100;// %age mass composition of CO2 produced
+x2 = m2/mt*100;// %age mass composition of H2O produced
+x3 = m3/mt*100;// %age mass composition of O2 produced
+x4 = m4/mt*100;// %age mass composition of N2 produced
+
+vt = x1/mCO2+x2/mH2O+x3/mO2+x4/mN2;// total volume
+v1 = x1/mCO2/vt*100;// %age volume composition of CO2
+v2 = x2/mH2O/vt*100;// %age volume composition of H2O
+v3 = x3/mO2/vt*100;// %age volume composition of O2
+v4 = x4/mN2/vt*100;// %age volume composition of N2
+
+Mav = (v1*mCO2+v2*mH2O+v3*mO2+v4*mN2)/(v1+v2+v3+v4);// average moleculer mass, [kg/kmol]
+// since no of moles is constant so PV/T=constant
+V2 = P1*V1*T2/(P2*T1);//volume, [m^3]
+
+mp = mt*mc/3600;// mass of product of combustion/s, [kg]
+
+V = V2*mp/Mav;// volume of flowing gas /s,[m^3]
+
+v = V/A;// velocity of flue gas, [m/s]
+mprintf('\n The actual mass of air supplied is = %f kg/kg coal\n',mas);
+mprintf('\n The velocity of flue gas is = %f m/s\n',v);
+
+// End
diff --git a/2705/CH8/EX8.19/Ex8_19.sce b/2705/CH8/EX8.19/Ex8_19.sce new file mode 100755 index 000000000..30bfc9211 --- /dev/null +++ b/2705/CH8/EX8.19/Ex8_19.sce @@ -0,0 +1,51 @@ +clear;
+clc;
+disp('Example 8.19');
+
+// aim : To determine
+// (a) the temperature of the gas after compression
+// (b) the density of the air-gas mixture
+
+// given values
+CO = 26;// %age volume composition of CO
+H2 = 16;// %age volume composition of H2
+CH4 = 7;// %age volume composition of CH4
+N2 = 51;// %age volume composition of N2
+
+P1 = 103;// gas pressure, [kN/m^2]
+T1 = 273+21;// gas temperature, [K]
+rv = 7;// volume ratio
+
+aO2 = 21;// %age volume composition of O2 in the air
+c = 21;// specific heat capacity of diatomic gas, [kJ/kg K]
+cCH4 = 36;// specific heat capacity of CH4, [kJ/kg K]
+R = 8.3143;// gas constant, [kJ/kg K]
+
+mCO = 28;// moleculer mass of carbon
+mH2 = 2;// molecular mass of hydrogen
+mCH4 = 16;// moleculer mas of methane
+mN2 = 28;// moleculer mass of nitrogen
+mO2 = 32;// moleculer mass of oxygen
+
+// solution
+// (a)
+Cav = (CO*c+H2*c+CH4*cCH4+N2*c+100*2*c)/(100+200);// heat capacity, [kJ/kg K]
+
+Gama = (Cav+R)/Cav;// heat capacity ratio
+// rv = V1/V2
+// process is polytropic, so
+T2 = T1*(rv)^(Gama-1);// final tempearture, [K]
+mprintf('\n (a) The temperature of the gas after compression is = %f C\n',T2-273);
+
+// (b)
+
+Mav = (CO*mCO+H2*mH2+CH4*mCH4+N2*mN2+42*mO2+158*mN2)/(100+200)
+
+// for 1 kmol of gas
+V = R*T1/P1;// volume of one kmol of gas, [m^3]
+// hence
+rho = Mav/V;// density of gas, [kg/m^3]
+
+mprintf('\n (b) The density of air-gas mixture is = %f kg/m^3\n',rho);
+
+// End
diff --git a/2705/CH8/EX8.20/Ex8_20.sce b/2705/CH8/EX8.20/Ex8_20.sce new file mode 100755 index 000000000..51e9a6f72 --- /dev/null +++ b/2705/CH8/EX8.20/Ex8_20.sce @@ -0,0 +1,19 @@ +clear;
+clc;
+disp('Example 8.20');
+
+// aim : to determine
+// stoichiometric equation for combustion of hydrogen
+
+// solution
+// equation with algebric coefficient is
+// H2+aO2+79/21*aN2=bH2O+79/21*aN2
+// by equating coefficients
+b = 1;
+a = b/2;
+// so equation becomes
+// 2 H2+ O2+3.76 N2=2 H2O+3.76 N2
+disp('The required stoichiometric equation is = ');
+disp('2 H2+ O2+3.76 N2 = 2 H2O+3.76 N2');
+
+// End
diff --git a/2705/CH8/EX8.22/Ex8_22.sce b/2705/CH8/EX8.22/Ex8_22.sce new file mode 100755 index 000000000..9e5bddbd5 --- /dev/null +++ b/2705/CH8/EX8.22/Ex8_22.sce @@ -0,0 +1,53 @@ +clear;
+clc;
+disp('Example 8.22');
+
+// aim : To determine
+// the percentage gravimetric analysis of the total products of combustion
+
+// given values
+CO = 12;// %age volume composition of CO
+H2 = 41;// %age volume composition of H2
+CH4 = 27;// %age volume composition of CH4
+O2 = 2;// %age volume composition of O2
+CO2 = 3;// %age volume composition of CO2
+N2 = 15;// %age volume composition of N2
+
+mCO2 = 44;// moleculer mass of CO2,[kg/kmol]
+mH2O = 18;// moleculer mass of H2O, [kg/kmol]
+mO2 = 32;// moleculer mass of O2, [kg/kmol]
+mN2 = 28;// moleculer mass of N2, [kg/kmol]
+
+ea = 15;// %age excess air required
+aO2 = 21;// %age air composition in the air
+
+// solution
+// combustion equation by no. of moles
+// 12CO + 41H2 + 27CH4 + 2O2 + 3CO2 + 15N2 + aO2+79/21*aN2 = bCO2 + dH2O + eO2 + 15N2 +79/21*aN2
+// equating C coefficient
+b = 12+27+3;// [mol]
+// equatimg H2 coefficient
+d = 41+2*27;// [mol]
+// O2 required is 15 % extra,so
+// e/(e-a)=.15 so e=.13a
+// equating O2 coefficient
+// 2+3+a=b+d/2 +e
+
+a = (b+d/2-5)/(1-.13);
+e = .13*a;// [mol]
+
+// gravimetric analysis of product
+v1 = b*mCO2;// gravimetric volume of CO2
+v2 = d*mH2O ;// gravimetric volume of H2O
+v3 = e*mO2;// gravimetric volume of O2
+v4 = 15*mN2 +79/21*a*mN2;// gravimetric volume of N2
+
+vt = v1+v2+v3+v4;// total
+x1 = v1/vt*100;// percentage gravimetric of CO2
+x2 = v2/vt*100;// percentage gravimetric of H2O
+x3 = v3/vt*100;// percentage gravimetric of O2
+x4 = v4/vt*100;// percentage gravimetric of N2
+
+mprintf('\n Percentage gravimetric composition of CO2 = %f\n ,\n Percentage gravimetric composition of H2O = %f\n\n Percentage gravimetric composition of O2 = %f\n\n Percentage gravimetric composition of N2 = %f\n',x1,x2,x3,x4);
+
+// End
diff --git a/2705/CH8/EX8.23/Ex8_23.sce b/2705/CH8/EX8.23/Ex8_23.sce new file mode 100755 index 000000000..6a5a20ce2 --- /dev/null +++ b/2705/CH8/EX8.23/Ex8_23.sce @@ -0,0 +1,54 @@ +clear;
+clc;
+disp('Example 8.23');
+
+// aim : To determine
+// (a) the actual quantity of air supplied/kg of fuel
+// (b) the volumetric efficiency of the engine
+
+// given values
+d = 300*10^-3;// bore,[m]
+L = 460*10^-3;// stroke,[m]
+N = 200;// engine speed, [rev/min]
+
+C = 87;// %age mass composition of Carbon in the fuel
+H2 = 13;// %age mass composition of H2 in the fuel
+
+mc = 6.75;// fuel consumption, [kg/h]
+
+CO2 = 7;// %age composition of CO2 by volume
+O2 = 10.5;// %age composition of O2 by volume
+N2 = 7;// %age composition of N2 by volume
+
+mC = 12;// moleculer mass of CO2,[kg/kmol]
+mH2 = 2;// moleculer mass of H2, [kg/kmol]
+mO2 = 32;// moleculer mass of O2, [kg/kmol]
+mN2 = 28;// moleculer mass of N2, [kg/kmol]
+
+T = 273+17;// atmospheric temperature, [K]
+P = 100;// atmospheric pressure, [kn/m^2]
+R =.287;// gas constant, [kJ/kg k]
+
+// solution
+// (a)
+// combustion equation by no. of moles
+// 87/12 C + 13/2 H2 + a O2+79/21*a N2 = b CO2 + d H2O + eO2 + f N2
+// equating coefficient
+b = 87/12;// [mol]
+a = 22.7;// [mol]
+e = 10.875;// [mol]
+f = 11.8*b;// [mol]
+// so fuel side combustion equation is
+// 87/12 C + 13/2 H2 +22.7 O2 +85.5 N2
+mair = ( 22.7*mO2 +85.5*mN2)/100;// mass of air/kg fuel, [kg]
+mprintf('\n (a) The mass of actual air supplied per kg of fuel is = %f kg\n',mair);
+
+// (b)
+m = mair*mc/60;// mass of air/min, [kg]
+V = m*R*T/P;// volumetric flow of air/min, [m^3]
+SV = %pi/4*d^2*L*N/2;// swept volume/min, [m^3]
+
+VE = V/SV;// volumetric efficiency
+mprintf('\n (b) The volumetric efficiency of the engine is = %fpercent\n',VE*100);
+
+// End
diff --git a/2705/CH8/EX8.24/Ex8_24.sce b/2705/CH8/EX8.24/Ex8_24.sce new file mode 100755 index 000000000..42ac180f3 --- /dev/null +++ b/2705/CH8/EX8.24/Ex8_24.sce @@ -0,0 +1,38 @@ +clear;
+clc;
+disp('Example 8.24');
+
+// aim : To determine
+// the mass of air supplied/kg of fuel burnt
+
+// given values
+// gas composition in the fuel
+C = 84;// %age mass composition of Carbon in the fuel
+H2 = 14;// %age mass composition of H2 in the fuel
+O2f = 2;// %age mass composition of O2 in the fuel
+
+// exhaust gas composition
+CO2 = 8.85;// %age composition of CO2 by volume
+CO = 1.2// %age composition of CO by volume
+O2 = 6.8;// %age composition of O2 by volume
+N2 = 83.15;// %age composition of N2 by volume
+
+mC = 12;// moleculer mass of CO2,[kg/kmol]
+mH2 = 2;// moleculer mass of H2, [kg/kmol]
+mO2 = 32;// moleculer mass of O2, [kg/kmol]
+mN2 = 28;// moleculer mass of N2, [kg/kmol]
+
+// solution
+// combustion equation by no. of moles
+// 84/12 C + 14/2 H2 +2/32 O2 + a O2+79.3/20.7*a N2 = b CO2 + d CO2+ eO2 + f N2 +g H2
+// equating coefficient and given condition
+b = 6.16;// [mol]
+a = 15.14;// [mol]
+d = .836;// [mol]
+f = 69.3*d;// [mol]
+// so fuel side combustion equation is
+// 84/12 C + 14/2 H2 +2/32 O2 + 15.14 O2 +85.5 N2
+mair = ( a*mO2 +f*mN2)/100;// mass of air/kg fuel, [kg]
+mprintf('\n The mass of air supplied per kg of fuel is = %f kg\n',mair);
+
+// End
diff --git a/2705/CH8/EX8.3/Ex8_3.sce b/2705/CH8/EX8.3/Ex8_3.sce new file mode 100755 index 000000000..6050727e8 --- /dev/null +++ b/2705/CH8/EX8.3/Ex8_3.sce @@ -0,0 +1,37 @@ +clear;
+clc;
+disp('Example 8.3');
+
+// aim : To determine
+// the stoichiometric mass of air
+// the products of combustion both by mass and as percentage
+
+// Given values
+C = .82;// mass composition C
+H2 = .12;// mass composition of H2
+O2 = .02;// mass composition of O2
+S = .01;// mass composition of S
+N2 = .03;// mass composition of N2
+
+ // solution
+// for 1kg fuel
+mo2 = 8/3*C+8*H2-O2+S*1;// total mass of O2 required, [kg]
+sa = mo2/.232;// stoichimetric air, [kg]
+mprintf('\n The stoichiometric mass of air is = %f kg/kg fuel\n',sa);
+
+// for one kg fuel
+mCO2 = C*11/3;// mass of CO2 produced, [kg]
+mH2O = H2*9;// mass of H2O produced, [kg]
+mSO2 = S*2;// mass of SO2 produce, [kg]
+mN2 = C*8.84+H2*26.5-O2*.768/.232+S*3.3+N2;// mass of N2 produced, [kg]
+
+mt = mCO2+mH2O+mSO2+mN2;// total mass of product, [kg]
+
+x1 = mCO2/mt*100;// %age mass composition of CO2 produced
+x2 = mH2O/mt*100;// %age mass composition of H2O produced
+x3 = mSO2/mt*100;// %age mass composition of SO2 produced
+x4 = mN2/mt*100;// %age mass composition of N2 produced
+
+mprintf('\n CO2 produced = %f kg/kg fuel, percentage composition = %f,\n H2O produced = %f kg/kg fuel, percentage composition = %f,\n SO2 produced = %f kg/kg fuel, percentage composition = %f,\n N2 produced = %f kg/kg fuel, percentage composition = %f',mCO2,x1,mH2O,x2,mSO2,x3,mN2,x4);
+
+// End
diff --git a/2705/CH8/EX8.4/Ex8_4.sce b/2705/CH8/EX8.4/Ex8_4.sce new file mode 100755 index 000000000..6938b2413 --- /dev/null +++ b/2705/CH8/EX8.4/Ex8_4.sce @@ -0,0 +1,25 @@ +clear;
+clc;
+disp('Example 8.4');
+
+// aim : To determine
+// the stoichiometric volume of air required for complete combution of 1 m^3 of the gas
+
+// Given values
+H2 = .14;// volume fraction of H2
+CH4 = .02;// volume fraction of CH4
+CO = .22;// volume fraction of CO
+CO2 = .05;// volume fraction of CO2
+O2 = .02;// volume fraction of O2
+N2 = .55;// volume fraction of N2
+
+// solution
+// for 1 m^3 of fuel
+Va = .5*H2+2*CH4+.5*CO-O2;// [m^3]
+
+// stoichiometric air required is
+Vsa = Va/.21;// [m^3]
+
+mprintf('\n The stoichiometric volume of air required for complete combustion is = %f m^3/m^3 fuel\n',Vsa);
+
+// End
diff --git a/2705/CH8/EX8.5/Ex8_5.sce b/2705/CH8/EX8.5/Ex8_5.sce new file mode 100755 index 000000000..a69209cb1 --- /dev/null +++ b/2705/CH8/EX8.5/Ex8_5.sce @@ -0,0 +1,21 @@ +clear;
+clc;
+disp('Example 8.5');
+
+// aim : To determine
+// the volume of the air required
+
+// Given values
+H2 = .45;// volume fraction of H2
+CO = .40;// volume fraction of CO
+CH4 = .15;// volume fraction of CH4
+
+// solution
+V = 2.38*(H2+CO)+9.52*CH4;// stoichimetric volume of air, [m^3]
+
+mprintf('\n The volume of air required is = %f m^3/m^3 fuel\n',V);
+
+// Result in the book is misprinted
+
+// End
+
diff --git a/2705/CH8/EX8.6/Ex8_6.sce b/2705/CH8/EX8.6/Ex8_6.sce new file mode 100755 index 000000000..fe97bb2fb --- /dev/null +++ b/2705/CH8/EX8.6/Ex8_6.sce @@ -0,0 +1,37 @@ +clear;
+clc;
+disp('Example 8.6');
+
+// aim : To determine
+// the stoichiometric volume of air for the complete combustion
+// the products of combustion
+
+// given values
+CH4 = .142;// volumetric composition of CH4
+CO2 = .059;// volumetric composition of CO2
+CO = .360;// volumetric composition of CO
+H2 = .405;// volumetric composition of H2
+O2 = .005;// volumetric composition of O2
+N2 = .029;// volumetric composition of N2
+
+aO2 = .21;// O2 composition into air by volume
+
+// solution
+svO2 = CH4*2+CO*.5+H2*.5-O2;// stroichiometric volume of O2 required, [m^3/m^3 fuel]
+svair = svO2/aO2;// stroichiometric volume of air required, [m^3/m^3 fuel]
+mprintf('\n Stoichiometric volume of air required is = %f m^3/m^3 fuel\n',svair);
+
+// for one m^3 fuel
+vN2 = CH4*7.52+CO*1.88+H2*1.88-O2*.79/.21+N2;// volume of N2 produced, [m^3]
+vCO2 = CH4*1+CO2+CO*1;// volume of CO2 produced, [m^3]
+vH2O = CH4*2+H2*1;// volume of H2O produced, [m^3]
+
+vt = vN2+vCO2+vH2O;// total volume of product, [m^3]
+
+x1 = vN2/vt*100;// %age composition of N2 in product,
+x2 = vCO2/vt*100;// %age composition of CO2 in product
+x3 = vH2O/vt*100;// %age composition of H2O in product
+
+mprintf('\n N2 in products = %fm^3/m^3 fuel, percentage composition = %f,\n CO2 in products = %f m^3/m^3 fuel, percentage composition = %f,\n H2O in products = %fm^3/m^3 fuel, percentage composition = %f',vN2,x1,vCO2,x2,vH2O,x3);
+
+// End
diff --git a/2705/CH8/EX8.7/Ex8_7.sce b/2705/CH8/EX8.7/Ex8_7.sce new file mode 100755 index 000000000..534f4f01e --- /dev/null +++ b/2705/CH8/EX8.7/Ex8_7.sce @@ -0,0 +1,25 @@ +clear;
+clc;
+disp('Example 8.7');
+
+// aim : To determine
+// the percentage analysis of the gas by mass
+
+// Given values
+CO2 = 20;// percentage volumetric composition of CO2
+N2 = 70;// percentage volumetric composition of N2
+O2 = 10;// percentage volumetric composition of O2
+
+mCO2 = 44;// moleculer mas of CO2
+mN2 = 28;// moleculer mass of N2
+mO2 = 32;// moleculer mass of O2
+
+// solution
+mgas = CO2*mCO2+N2*mN2+O2*mO2;// moleculer mass of gas
+m1 = CO2*mCO2/mgas*100;// percentage composition of CO2 by mass
+m2 = N2*mN2/mgas*100;// percentage composition of N2 by mass
+m3 = O2*mO2/mgas*100;// percentage composition of O2 by mass
+
+mprintf('\n Mass percentage of CO2 is = %f\n\n Mass percentage of N2 is = %f\n\n Mass percentage of O2 is = %f\n',m1,m2,m3 )
+
+// End
diff --git a/2705/CH8/EX8.8/Ex8_8.sce b/2705/CH8/EX8.8/Ex8_8.sce new file mode 100755 index 000000000..347ec4c01 --- /dev/null +++ b/2705/CH8/EX8.8/Ex8_8.sce @@ -0,0 +1,31 @@ +clear;
+clc;
+disp('Example 8.8');
+
+// aim : To determine
+// the percentage composition of the gas by volume
+
+// given values
+CO = 30;// %age mass composition of CO
+N2 = 20;// %age mass composition of N2
+CH4 = 15;// %age mass composition of CH4
+H2 = 25;// %age mass composition of H2
+O2 = 10;// %age mass composition of O2
+
+mCO = 28;// molculer mass of CO
+mN2 = 28;// molculer mass of N2
+mCH4 = 16;// molculer mass of CH4
+mH2 = 2;// molculer mass of H2
+mO2 = 32;// molculer mass of O2
+
+// solution
+vg = CO/mCO+N2/mN2+CH4/mCH4+H2/mH2+O2/mO2;
+v1 = CO/mCO/vg*100;// %age volume composition of CO
+v2 = N2/mN2/vg*100;// %age volume composition of N2
+v3 = CH4/mCH4/vg*100;// %age volume composition of CH4
+v4 = H2/mH2/vg*100;// %age volume composition of H2
+v5 = O2/mO2/vg*100;// %age volume composition of O2
+
+mprintf('\n The percentage composition of CO by volume is = %f\n,\nThe percentage composition of N2 by volume is = %f\n\nThe percentage composition of CH4 by volume is = %f\n\nThe percentage composition of H2 by volume is = %f\n\nThe percentage composition of O2by volume is=%f',v1,v2,v3,v4,v5);
+
+// End
diff --git a/2705/CH8/EX8.9/Ex8_9.sce b/2705/CH8/EX8.9/Ex8_9.sce new file mode 100755 index 000000000..0528a2575 --- /dev/null +++ b/2705/CH8/EX8.9/Ex8_9.sce @@ -0,0 +1,44 @@ +clear;
+clc;
+disp('Example 8.9');
+
+// aim : To determine
+// the mass of air supplied per kilogram of fuel burnt
+
+// given values
+CO2 = 8.85;// volume composition of CO2
+CO = 1.2;// volume composition of CO
+O2 = 6.8;// volume composition of O2
+N2 = 83.15;// volume composition of N2
+
+// composition of gases in the fuel oil
+C = .84;// mass composition of carbon
+H = .14;// mass composition of hydrogen
+o2 = .02;// mass composition of oxygen
+
+mC = 12;// moleculer mass of Carbon
+mCO2 = 44;// molculer mass of CO2
+mCO = 28;// molculer mass of CO
+mN2 = 28;// molculer mass of N2
+mO2 = 32;// molculer mass of O2
+aO2 = .23;// mass composition of O2 in air
+
+// solution
+ma = (8/3*C+8*H-o2)/aO2;// theoretical mass of air/kg fuel, [kg]
+
+mgas = CO2*mCO2+CO*mCO+N2*mN2+O2*mO2;// total mass of gas/kg fuel, [kg]
+x1 = CO2*mCO2/mgas;// composition of CO2 by mass
+x2 = CO*mCO/mgas;// composition of CO by mass
+x3 = O2*mO2/mgas;// composition of O2 by mass
+x4 = N2*mN2/mgas;// composition of N2 by mass
+
+m1 = x1*mC/mCO2+x2*mC/mCO;// mass of C/kg of dry flue gas, [kg]
+m2 = C;// mass of C/kg fuel, [kg]
+mf = m2/m1;// mass of dry flue gas/kg fuel, [kg]
+mo2 = mf*x3;// mass of excess O2/kg fuel, [kg]
+mair = mo2/aO2;// mass of excess air/kg fuel, [kg]
+m = ma+mair;// mass of excess air supplied/kg fuel, [kg]
+
+mprintf('\n The mass of air supplied per/kg of fuel burnt is = %f kg\n',m);
+
+// End
diff --git a/2705/CH9/EX9.1/Ex9_1.sce b/2705/CH9/EX9.1/Ex9_1.sce new file mode 100755 index 000000000..4a04d7b87 --- /dev/null +++ b/2705/CH9/EX9.1/Ex9_1.sce @@ -0,0 +1,32 @@ +clear;
+clc;
+disp('Example 9.1');
+
+// aim : To determine
+// the heat loss per hour through the wall and interface temperature
+
+// Given values
+x1 = .25;// thickness of brick,[m]
+x2 = .05;// thickness of concrete,[m]
+t1 = 30;// brick face temperature,[C]
+t3 = 5;// concrete face temperature,[C]
+l = 10;// length of the wall, [m]
+h = 5;// height of the wall, [m]
+k1 = .69;// thermal conductivity of brick,[W/m/K]
+k2 = .93;// thermal conductivity of concrete,[W/m/K]
+
+// solution
+A = l*h;// area of heat transfer,[m^2]
+Q_dot = A*(t1-t3)/(x1/k1+x2/k2);// heat transferred, [J/s]
+
+// so heat loss per hour is
+Q = Q_dot*3600*10^-3;// [kJ]
+mprintf('\n The heat lost per hour is = %f kJ\n',Q);
+
+// interface temperature calculation
+// for the brick wall, Q_dot=k1*A*(t1-t2)/x1;
+// hence
+t2 = t1-Q_dot*x1/k1/A;// [C]
+mprintf('\n The interface temperature is = %f C\n',t2);
+
+// End
diff --git a/2705/CH9/EX9.2/Ex9_2.sce b/2705/CH9/EX9.2/Ex9_2.sce new file mode 100755 index 000000000..1a60b1763 --- /dev/null +++ b/2705/CH9/EX9.2/Ex9_2.sce @@ -0,0 +1,35 @@ +clear;
+clc;
+disp('Example 9.2');
+
+// aim : To determine
+// the minimum
+// thickness of the lagging required
+
+// Given values
+r1 = 75/2;// external radious of the pipe,[mm]
+L = 80;// length of the pipe,[m]
+m_dot = 1000;// flow of steam, [kg/h]
+P = 2;// pressure, [MN/m^2]
+x1 = .98;// inlet dryness fraction
+x2 = .96;// outlet dryness fraction
+k = .08;// thermal conductivity of of pipe, [W/m/K]
+t2 = 27;// outside temperature,[C]
+
+// solution
+// using steam table at 2 MN/m^2 the enthalpy of evaporation of steam is,
+hfg = 1888.6;// [kJ/kg]
+// so heat loss through the pipe is
+Q_dot = m_dot*(x1-x2)*hfg/3600;// [kJ]
+
+// also from steam table saturation temperature of steam at 2 MN/m^2 is,
+t1 = 212.4;// [C]
+// and for thick pipe, Q_dot=k*2*%pi*L*(t1-t2)/log(r2/r1)
+// hence
+r2 = r1*exp(k*2*%pi*L*(t1-t2)*10^-3/Q_dot);// [mm]
+
+t = r2-r1;// thickness, [mm]
+
+mprintf('\n The minimum thickness of the lagging required is = %f mm\n',t);
+
+// End
diff --git a/2705/CH9/EX9.3/Ex9_3.sce b/2705/CH9/EX9.3/Ex9_3.sce new file mode 100755 index 000000000..0901fd861 --- /dev/null +++ b/2705/CH9/EX9.3/Ex9_3.sce @@ -0,0 +1,41 @@ +clear;
+clc;
+disp('Example 9.3');
+
+// aim : To determine the
+// (a) heat loss per hour
+// (b) interface temperature og lagging
+
+// Given values
+r1 = 50; // radious of steam main,[mm]
+r2 = 90;// radious with first lagging,[mm]
+r3 = 115;// outside radious os steam main with lagging,[mm]
+k1 = .07;// thermal conductivity of 1st lagging,[W/m/K]
+k2 = .1;// thermal conductivity of 2nd lagging, [W/m/K]
+P = 1.7;// steam pressure,[MN/m^2]
+t_superheat = 30;// superheat of steam, [K]
+t3 = 24;// outside temperature of the lagging,[C]
+L = 20;// length of the steam main,[m]
+
+// solution
+// (a)
+// using steam table saturation temperature of steam at 1.7 MN/m^2 is
+t_sat = 204.3;// [C]
+// hence
+t1 = t_sat+t_superheat;// temperature of steam,[C]
+
+Q_dot = 2*%pi*L*(t1-t3)/(log(r2/r1)/k1+log(r3/r2)/k2);// heat loss,[W]
+// heat loss in hour is
+Q = Q_dot*3600*10^-3;// [kJ]
+
+mprintf('\n (a) The heat lost per hour is = %f kJ\n',Q);
+
+// (b)
+// using Q_dot=2*%pi*k1*(t1-t1)/log(r2/r1)
+t2 = t1-Q_dot*log(r2/r1)/(2*%pi*k1*L);// interface temperature of lagging,[C]
+
+mprintf('\n (b) The interface temperature of the lagging is = %f C\n',t2);
+
+// There is some calculation mistake in the book so answer is not matching
+
+// End
diff --git a/2705/CH9/EX9.4/Ex9_4.sce b/2705/CH9/EX9.4/Ex9_4.sce new file mode 100755 index 000000000..b6f5f4106 --- /dev/null +++ b/2705/CH9/EX9.4/Ex9_4.sce @@ -0,0 +1,22 @@ +clear;
+clc;
+disp('Example 9.4');
+
+// aim : To determine
+// the energy emetted from the surface
+
+// Given values
+h = 3;// height of surface, [m]
+b = 4;// width of surface, [m]
+epsilon_s = .9;// emissivity of the surface
+T = 273+600;// surface temperature ,[K]
+sigma = 5.67*10^-8;// [W/m^2/K^4]
+
+// solution
+As = h*b;// area of the surface, [m^2]
+
+Q_dot = epsilon_s*sigma*As*T^4*10^-3;// energy emitted, [kW]
+
+mprintf('\n The energy emitted from the surface is = %f kW\n',Q_dot);
+
+// End
diff --git a/2705/CH9/EX9.5/Ex9_5.sce b/2705/CH9/EX9.5/Ex9_5.sce new file mode 100755 index 000000000..e916c7e40 --- /dev/null +++ b/2705/CH9/EX9.5/Ex9_5.sce @@ -0,0 +1,34 @@ +clear;
+clc;
+disp('Example 9.5');
+
+// aim : To determine
+// the rate of energy transfer between furnace and the sphere and its direction
+
+// Given values
+l = 1.25;// internal side of cubical furnace, [m]
+ti = 800+273;// internal surface temperature of the furnace,[K]
+r = .2;// sphere radious, [m]
+epsilon = .6;// emissivity of sphere
+ts = 300+273;// surface temperature of sphere, [K]
+sigma = 5.67*10^-8;// [W/m^2/K^4]
+
+// Solution
+Af = 6*l^2;// internal surface area of furnace, [m^2]
+As =4 *%pi*r^2;// surface area of sphere, [m^2]
+
+// considering internal furnace to be black
+Qf = sigma*Af*ti^4*10^-3;// [kW]
+
+// radiation emitted by sphere is
+Qs = epsilon*sigma*As*ts^4*10^-3; // [kW]
+
+// Hence transfer of energy is
+Q = Qf-Qs;// [kW]
+
+mprintf('\n The transfer of energy will be from furnace to sphere and transfer rate is = %f kW\n',Q);
+
+// There is some calculation mistake in the book so answer is not matching
+
+// End
+
diff --git a/2705/CH9/EX9.6/Ex9_6.sce b/2705/CH9/EX9.6/Ex9_6.sce new file mode 100755 index 000000000..07386e7e2 --- /dev/null +++ b/2705/CH9/EX9.6/Ex9_6.sce @@ -0,0 +1,34 @@ +clear;
+clc;
+disp('Example 9.6');
+
+// aim : To determine
+// the overall transfer coefficient and the heat loss per hour
+
+// Given values
+x1 = 25*10^-3;// Thickness of insulating board, [m]
+x2 = 75*10^-3;// Thickness of fibreglass, [m]
+x3 = 110*10^-3;// Thickness of brickwork, [m]
+k1 = .06;// Thermal conductivity of insulating board, [W/m K]
+k2 = .04;// Thermal conductivity of fibreglass, [W/m K]
+k3 = .6;// Thermal conductivity of brickwork, [W/m K]
+Us1 = 2.5;// surface heat transfer coefficient of the inside wall,[W/m^2 K]
+Us2 = 3.1;// surface heat transfer coefficient of the outside wall,[W/m^2 K]
+ta1 = 27;// internal ambient temperature, [C]
+ta2 = 10;// external ambient temperature, [C]
+h = 6;// height of the wall, [m]
+l = 10;// length of the wall, [m]
+
+// solution
+U = 1/(1/Us1+x1/k1+x2/k2+x3/k3+1/Us2);// overall heta transfer coefficient,[W/m^2 K]
+
+A = l*h;// area ,[m^2]
+
+Q_dot = U*A*(ta1-ta2);// heat loss [W]
+
+// so heat loss per hour is
+Q = Q_dot*3600*10^-3;// [kJ]
+mprintf('\n The overall heat transfer coefficient for the wall is = %f W/m^2 K\n',U);
+mprintf('\n The heat loss per hour through the wall is = %f kJ\n',Q);
+
+// End
diff --git a/2705/CH9/EX9.7/Ex9_7.sce b/2705/CH9/EX9.7/Ex9_7.sce new file mode 100755 index 000000000..4af2d8450 --- /dev/null +++ b/2705/CH9/EX9.7/Ex9_7.sce @@ -0,0 +1,44 @@ +clear;
+clc;
+disp('Example 9.7');
+
+// aim : To determine
+// the heat loss per hour and the surface temperature of the lagging
+
+// Given values
+r1 = 75*10^-3;// External radiou of the pipe, [m]
+t_l1 = 40*10^-3;// Thickness of lagging1, [m]
+t_l2 = t_l1;
+k1 = .07;// thermal conductivity of lagging1, [W/m K]
+k2 = .1;// thermal conductivity of lagging2, [W/m K]
+Us = 7;// surface transfer coefficient for outer surface, [W/m^2 K]
+L = 50;// length of the pipe, [m]
+ta = 27;// ambient temperature, [C]
+P = 3.6;// wet steam pressure, [MN/m^2]
+
+// solution
+// from steam table saturation temperature of the steam at given pressure is,
+t1 = 244.2;// [C]
+r2 = r1+t_l1;// radious of pipe with lagging1,[m]
+r3 = r2+t_l2;// radious of pipe with both the lagging, [m]
+
+R1 = log(r2/r1)/(2*%pi*L*k1);// resistance due to lagging1,[C/W]
+R2 = log(r3/r2)/(2*%pi*L*k2);// resistance due to lagging2,[C/W]
+R3 = 1/(Us*2*%pi*r3*L);// ambient resistance, [C/W]
+
+// hence overall resistance is,
+Req = R1+R2+R3;// [C/W]
+tdf = t1-ta;// temperature driving force, [C]
+Q_dot = tdf/Req;// rate of heat loss, [W]
+// so heat loss per hour is,
+Q = Q_dot*3600*10^-3;// heat loss per hour, [kJ]
+
+// using eqn [3]
+t3 = ta+Q_dot*R3;// surface temperature of the lagging, [C]
+
+mprintf('\n The heat loss per hour is = %f kJ\n',Q);
+mprintf('\n The surface temperature of the lagging is = %f C\n',t3);
+
+// there is minor variation in the answer
+
+// End
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