Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Diesel engine prob

  1. Apr 21, 2010 #1
    how would you find the correct formula for the temp at state 3 and 4. i found it for 1 and 2
  2. jcsd
  3. Apr 21, 2010 #2
    Hello Waterboy.

    First, I would ask that when you have a question try to be specific and do not abbreviate the words, because many members here are from different countries and areas.

    For an air standard cycle, whose fuel is Diesel:

    To calculate the temperature in the cycle expansion (3), it will be the point of greatest pressure and higher temperature, use the formula:

    T3 = T2 + (Q1 / (m * cp);


    Q1 = heat input
    T2 = temperature cycle 2
    m = mass
    cp = specific heat of gas at constant pressure

    To obtain the temperature in the cycle of the removal of heat (4) you must have the values of compression ratio in cycles 3 (V3) and 4 (V4) and the adiabatic constant of air (k), and the temperature in the expansion cycle (3).

    T4 = T3 * (V3/V4) ^ (k-1);


    T3 = temperature in cycle 3
    V3 = volume in the cycle 3
    V4 = volume in the cycle 4
    k = constant adiabatic air

    If you have any questions about the theory of everything, or to obtain Q1 or mass simply send an email. I am new in this form too and do not know to use mathematical symbols, if someone can explain me please tell me.

    I hope this can help.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Diesel engine prob
  1. Diesel engines. (Replies: 11)