1 files changed, 43 insertions, 0 deletions
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
+