1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Thermodynamics (jet engine)

  1. Oct 15, 2008 #1
    1. The problem statement, all variables and given/known data


    2. Relevant equations

    3. The attempt at a solution

    H = U + pV is the enthalpy, and hence the enthalpy per unit mass is h = U/m + pV/m which I have simplified to 7/2 RT/M

    I am then able to derive the expression in part b).

    Part c) though I'm very confused about, and then moving onto d) I'm pretty lost. I realise that in part say, to get change in T = 2Mq/7R, I can either set vf = vi = 0, or just simply vf = vi works too (where vf is final velocity and vi initial velocity). If someone could just point me in the right direction, that'd be awesome.

    For part d) dQ = 0 as its adiabatically compressed. Work done on the gas is p dV, and so dU = dQ + dW = pdV. p isn't constant, so I tried to rewrite as dU = nR dT (going for the long shots here hoping it will take me somewhere). Seeing as I seem to be going completely along the wrong lines, I'm not going to carry on..

    Any help is appreciated, thanks.
  2. jcsd
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Can you help with the solution or looking for help too?

Similar Discussions: Thermodynamics (jet engine)