Work and heat transfer in internal combustion engine

[Suman_babai]

Homework Statement

: [/B]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. Homework Equations : I hv written all formulas in the solution (attachment).

The Attempt at a Solution

:[/B] 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.

 

[Replusz]

given by PV^1.2 = const.

Are yo usure this is not pV^1.4 ?

 

[Suman_babai]

Are yo usure this is not pV^1.4 ?

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

 

[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. )

 

[Suman_babai]

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. )

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

 

[Er Aditya]

Homework Statement

: [/B]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. Homework Equations : I hv written all formulas in the solution (attachment).

The Attempt at a Solution

:[/B] 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.

Here is correct solution bro. V1-V2= Volume swept by piston.
Volume swept by piston not equal to v1, where you went wrong.