Homework Help: Work and heat transfer in internal combustion engine

1. Dec 20, 2016

Suman_babai

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1. The problem statement, all variables and given/known data: At the beginning of the compression stroke of a two-cylinder internal combustion engine the air is at a pressure of 101.325 kPa. Compression redeuces the volume to 1/5 of its original volume, and the law of compression is given by PV^1.2 = const. If the bore and stroke of each cylinder is 0.15 m and 0.25 m , respectively, determine the power absorbed in kW by compression strokes when the engine speed is such that each cylinder undergoes 500 compression strokes per minute.

The answer is given as : 17.95 kW

2. Relevant equations :
I hv written all formulas in the solution (attachment).

3. The attempt at a solution: I hv attached the solution I hv done. Please rectify my mistake... where I am doing wrong..my ans is not matching with the given one.

Attached Files:

• IMG-20161220-WA0010.jpeg
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Last edited: Dec 20, 2016
2. Dec 21, 2016

Replusz

Are yo usure this is not pV^1.4 ?

3. Dec 21, 2016

Suman_babai

that could be a printing mstake... thanks... this book is just full of calculation errors.

4. Dec 21, 2016

Replusz

And if you calculate it with 1.4? do you get the right answer? (it is 1.4 because for adiabatic expressions pV^(1+2/f)=const. and f=5 for air. )

5. Dec 23, 2016

Suman_babai

no.. it is coming around 16.(something)... may be the question is wrong.. thanks anyway.