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!

SFEE + Air Question (REPLY SOON PLEASE)

  1. May 9, 2009 #1
    1. The problem statement, all variables and given/known data

    See attachment please (Note: a lot of extra information is given, all of the information given for the compressor is possibly redundant).

    2. Relevant equations

    1) SFEE (steady flow energy equation): q + W = (h2 - h1) + c2^2 - c1^1/2000 + g(z2 - z1)/1000

    2) Isentropic relationship: T2/T1 = (p2/p1)^(y-1/y).. (where y = gamma = 1.4)

    3. The attempt at a solution

    Apply the SFEE to find T2, but how?

    I have tried the following:

    q + W = (h2 - h1) + c2^2 - c1^1/2000 + g(z2 - z1)/1000.. where W = 0 (no shaft used), c2^2 - c1^1/2000 = 0 (no velocity information provided) and g(z2 - z1)/1000 = 0 (no change in height).

    Therefore: q = (h2 - h1)
    q = cp (T2 - T1).. where cp = 1.01kg/K, and cp (T2 - T1) is (h2 - h1) for an isobaric process.

    Multiplying both sides of the equation by mass flow rate (so that the power given (i.e. heat) can be used in the equation).
    q x m = heat energy [kW].

    I get an answer of 5229.3 degrees C. (convert units to Kelvins during calculations).


    Thanks in advance.
    Koen.
     

    Attached Files:

    Last edited: May 9, 2009
  2. jcsd
  3. May 10, 2009 #2
    Never mind. I got my answer.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: SFEE + Air Question (REPLY SOON PLEASE)
  1. Air Plane question (Replies: 1)

  2. Air Plane question (Replies: 1)

Loading...