From b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b Mon Sep 17 00:00:00 2001 From: priyanka Date: Wed, 24 Jun 2015 15:03:17 +0530 Subject: initial commit / add all books --- 2705/CH15/EX15.8/Ex15_8.sce | 65 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) create mode 100755 2705/CH15/EX15.8/Ex15_8.sce (limited to '2705/CH15/EX15.8') 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 -- cgit