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clc
y=1.4;
cv=0.718; //kJ/kg.K
m=1; //kg
T1=290; //K
n=1.3;
r=16;
y=1.4;
T2=T1*(r)^(n-1);
disp("(a)")
T=[T1 300 310 320 330 340 350 360 370 380 390 400 410 420 430 440 450 460 470 480 490 500 510 520 530 540 550 560 570 580 590 600 610 620 630 640 650 660 T2];
function s=f(T)
s=(y-n)*cv/(1-n)/10^3*log(T);
endfunction
s=[f(T1) f(300) f(310) f(320) f(330) f(340) f(350) f(360) f(370) f(380) f(390) f(400) f(410) f(420) f(430) f(440) f(450) f(460) f(470) f(480) f(490) f(500) f(510) f(520) f(530) f(540) f(550) f(560) f(570) f(580) f(590) f(600) f(610) f(620) f(630) f(640) f(650) f(660) f(T2)];
plot(s,T)
T=[0 T2];
s=[f(T2) f(T2)];
plot(s,T,'r--')
T=[0 T1];
s=[f(T1) f(T1)];
plot(s,T,'r--')
T=[T1 T2];
s=[f(T1) f(T2)];
plot(s,T,'r--')
xtitle("T-s diagram", "s", "T")
legend("p*v^n=c")
//Heat transferred = Area of trapezium = Base*mean ordinate
//Heat transferred=dS*(T1+T2)/2
//Hence we get
disp("Entropy change=Heat transferred/Mean absolute temperature")
disp("(b)Entropy change")
dS=cv*((n-y)/(n-1))*log(T2/T1);
disp("dS=")
disp(dS)
disp("kJ/kg.K")
disp("There is decrease in entropy")
Q=cv*((y-n)/(n-1))*(T1-T2);
Tmean = (T1+T2)/2;
dS_app=Q/Tmean;
%error=((-dS) - (-dS_app))/(-dS) * 100;
disp("%age error =")
disp(%error)
disp("%")
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