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/EX15.7/Ex15_7.sce | 68 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 68 insertions(+) create mode 100755 2705/CH15/EX15.7/Ex15_7.sce (limited to '2705/CH15/EX15.7/Ex15_7.sce') 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 -- cgit