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Homework Help: Work and heat transfer in internal combustion engine

  1. Dec 20, 2016 #1
    • ★★ members are requested to crop images so that only that content essential to the thread is posted ★★ ❌
    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:

    Last edited: Dec 20, 2016
  2. jcsd
  3. Dec 21, 2016 #2
    Are yo usure this is not pV^1.4 ?
  4. Dec 21, 2016 #3
    that could be a printing mstake... thanks... this book is just full of calculation errors.
  5. Dec 21, 2016 #4
    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. )
  6. Dec 23, 2016 #5
    no.. it is coming around 16.(something)... may be the question is wrong.. thanks anyway.
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