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Homework Help: Diesel Engine Problem - Find total work

  1. Oct 20, 2011 #1
    1. The problem statement, all variables and given/known data

    The problem is in the attached document

    2. Relevant equations

    attached in pdf document

    3. The attempt at a solution

    1->2 adiabatic compression

    T2=(V2/V1)^1-(Cp/Cv) = 987.7K
    w1=nCvdT = (1mol)((3/2)*8.314J/molK)(987.7K-298K) = 8601.3 J

    2->3 w2=-PdV=-Pmax(V3-V2) = 66.29bar(V3-0.1L)

    3->4 w=nCvdT = (1 mol)(3*8.314J/molK)(T4-T3)

    4->1 w=0
    dH=nCpdT????
     

    Attached Files:

  2. jcsd
  3. Oct 21, 2011 #2
    "2->3 w2=-PdV=-Pmax(V3-V2) = 66.29bar(V3-0.1L)"

    This relationship is for a reversible isothermal process. 2-3 is the combustion portion of the cycle and is not isothermal. This can be noted on a temperature-entropy plot for the diesel cycle.
     
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