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The compression ratio of an engine is 10 and the temperature and pressure at the start...

The compression ratio of an engine is 10 and the temperature and pressure at the start of compression is 370 Celcius degree and 1 bar. The compression and expansion processes are both isentropic and the heat rejected at exhaust at constant volume. The amount of heat added during the cycle is 3000 kJ/kg.
Determine the mean effective pressure and thermal efficiency of the cycle if the maximum pressure is limited to 70 bar and heat added at both constant volume and constant pressure.
Assume that the charge has the same physical properties as that of air.

Note: k=1.4, Cv=0.717 kJ/kgK, R=0.287 kJ/kgK
75 minutes,

Engineering   Mechanical-Engineering   
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Homework Answers

Answer #1

To find Q(out) T5 is found out

From Q(out) thermal efficiency is found out

From thermal efficiency Work is found out and then P(mean) can be computed.

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