1. Limited time only! Sign up for a free 30min personal 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!

Homework Help: Thermodynamics compressor Question

  1. Dec 12, 2006 #1
    1. The problem statement, all variables and given/known data

    Air enters a compressor operating at a steady state with a pressure of 14.7 psi, a temperature of 70 F , and a volumetric flow rate of 500 ft^3/min. The air velocity in the exit pipe is 700ft/s and the exit pressure is 120 psi. If each unit mass of air passing from the inlet to the exit undergoes a process described by pv^1.34= constant determine the exit temperature on F and the diameter of the exit pipe in inches. What is the isentropic efficiency of the compressor?

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Dec 12, 2006 #2


    User Avatar

    Staff: Mentor

    Jason, Welcome to the PF, but do NOT post multiple threads with the same question in other forums. I've deleted the two other copies of this question, and left this one here in the homework forum where it belongs. You are also receiving a warning via the PF warning system.

    You also need to show your work so far in order for us to help you (PF rules).
  4. Dec 12, 2006 #3


    User Avatar

    Staff: Mentor

    I moved this thread to the Intro Physics homework forum where it will probably get more looks. Jason -- you still need to post some work for us to help you.
  5. Dec 12, 2006 #4


    User Avatar
    Science Advisor

    Part 1: What can you say about relationships between temperature and pressure in a polytropic process for an ideal gas?

    Part 2: What can you say about the mass flow rate of air entering and leaving the compressor?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook