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Diffstat (limited to '551/CH13/EX13.14/14.sce')
-rwxr-xr-x | 551/CH13/EX13.14/14.sce | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/551/CH13/EX13.14/14.sce b/551/CH13/EX13.14/14.sce new file mode 100755 index 000000000..cdcd079d5 --- /dev/null +++ b/551/CH13/EX13.14/14.sce @@ -0,0 +1,39 @@ +clc
+
+// W=Qs-Qr=cv*(T3-T2) - cv*(T4-T1)
+// T2=T1*(r^(y-1))
+// T3=T4*(r^(y-1))
+// W=cv*[T3-T1*r^(y-1) - T3/r^(y-1)+T1];
+// dW/dr=-T1*(y-1)*r^(y-2) - T3*(1-y)*r^(-y)=0
+
+//By solving this we get
+
+disp("r=(T3/T1)^(1/2/(y-1))")
+
+disp("(b)Change in efficiency")
+
+T3=1220; //K
+T1=310; //K
+
+// For air
+y=1.4;
+r1=(T3/T1)^(1/2/(y-1));
+n1=1-1/r1^(y-1); //air standard Efficiency
+disp("Air standard Efficiency =")
+disp(n1)
+
+//For helium
+cp=5.22; //kJ/kg K
+cv=3.13; //kJ/kg K
+y=cp/cv;
+r2=(T3/T1)^(1/2/(y-1));
+
+n2=1-1/r2^(y-1);
+disp("Air standard efficiency for helium =")
+disp(n2)
+
+change=n1-n2;
+disp("Change in efficiency=")
+disp(change)
+
+disp("Hence change in efficiency is nil")
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