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

Engine Turbochargers and Intercoolers

  1. Aug 12, 2011 #1
    The power output of an automobile engine is directly proportional to the mass of air that can be forced into the volume of the engine's cylinders to react chemically with gasoline. Many cars have a turbocharger which compresses the air before it enters the engine, giving a greater mass of air per volume. This rapid, essentially adiabatic compression also heats the air. To compress it further, the air then passes through an intercooler in which the air exchanges heat with its surroundings at essentially constant pressure. The air is then drawn into the cylinders. In a typical installation, air is taken into the turbocharger at atmospheric pressure 1.01 x 10^5Pa, density rho = 1.23 , kg/m^3, and temperature 15.0 ^C. It is compressed adiabatically to 1.45x 10^5 Pa. In the intercooler, the air is cooled to the original temperature of 15.0 C at a constant pressure of 1.45x 10^5Pa.

    If the volume of one of the engine's cylinders is 575 , cm^3, what mass of air exiting from the intercooler will fill the cylinder at 1.45 x10^5Pa?

    m=nM, where M is the molar mass

    So i solved for n and got PV/RT=n

    m=(PV/RT)M, where M is .029

    P=1.45 x 10^5
    V=575 x 10^-6

    plug it in and i got 9.75 x10^-4, does that seem reasonable for an engine?

    Im thinking its wrong but im not sure why
  2. jcsd
  3. Aug 13, 2011 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    Without showing your units who knows?
  4. Aug 13, 2011 #3
    Everything was converted to standard units

    P=1.45 x 10^5 P
    V=575 x 10^-6 m^3
    T=298 K

    so my answer would be 9.75 x10^-4 m^3
    Last edited: Aug 13, 2011
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook