Timeline for Why is the net entropy change of an irreversible engine positive?
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| Feb 5, 2016 at 20:19 | comment | added | lesnik | Now to your question about efficiency. The amount of work the engine produces in one cycle is the area of the cycle on PV diagram. But for not ideal Carnot engine the area would be smaller! Because the temperature (and hence the pressure) of the gas when it contacts the heater is less than in ideal case, and when gas contacts the cooler it's higher then in ideal case. | |
| Feb 5, 2016 at 19:15 | comment | added | lesnik | When some small amount of heat $Q$ is transferred away from a body at temperature $T$ it's entropy decreases by $Q/T$. But the same amount of heat come to a cooler body and it's entropy increases by $Q/T1$. Total difference is positive as $T1<T$. | |
| Feb 5, 2016 at 10:51 | comment | added | nayana v | How can entropy increase (I also want to know why does efficiency of engine decrease) if there is a finite difference in temperature of gas and the heater(and cooler) | |
| Feb 4, 2016 at 8:21 | review | Low quality answers | |||
| Feb 4, 2016 at 11:14 | |||||
| Feb 4, 2016 at 7:10 | review | First posts | |||
| Feb 4, 2016 at 8:17 | |||||
| Feb 4, 2016 at 7:05 | history | answered | lesnik | CC BY-SA 3.0 |