Chapter-6 Entropy
Chapter-6 Entropy
Chapter-6 Entropy
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.<br />
The value of the integral depends on the end states on;y and not the<br />
path followed.<br />
This represents the change of a property.<br />
This is called entropy, S .<br />
dS<br />
Q<br />
( ) int rev<br />
T<br />
( kJ )<br />
K<br />
<strong>Entropy</strong> is an extensive property.<br />
2<br />
Q<br />
2 1 ( int rev<br />
T<br />
1<br />
The entropy change of a system: S<br />
S S )<br />
)<br />
Example: air temperature is raised from T1 to T2<br />
Q<br />
W<br />
Q<br />
<br />
S<br />
2<br />
1<br />
0<br />
dU<br />
<br />
<br />
Q<br />
(<br />
)<br />
T<br />
dU<br />
mC<br />
v<br />
intrev<br />
dT<br />
<br />
2<br />
<br />
1<br />
mCvdT<br />
T<br />
<br />
mC<br />
v<br />
T<br />
ln<br />
T<br />
2<br />
1<br />
Thermal<br />
insulation<br />
( kJ K<br />
Air<br />
Q
Change language