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: Temperature problem in fluids mechanics

  1. Feb 8, 2012 #1
    1. The problem statement, all variables and given/known data
    Assume the temperature of the exhaust in an exhaust pipe can be approximated by
    T=T0(1+ae-bx)[1+c cos([itex]\omega[/itex]t)]
    [itex]\omega[/itex]=100 rad/s.

    If the exhaust speed is a constant 3 m/s, determine the time rate of change of temperature of the fluid particle at x=0 and x=4 m when t=0.

    2. Relevant equations
    We know the equation of the temperature in function of the time and the position
    T=T0(1+ae-bx)[1+c cos([itex]\omega[/itex]t)]

    3. The attempt at a solution
    We know that the time rate of change of temperature of the fluid particle is dT/dt

    [itex]\frac{dT}{dt}[/itex]=T0(1+ae-bx)[-c [itex]\omega[/itex] sin([itex]\omega[/itex]t)]

    When t=0, dT/dt=0... unfortunately that isn't the answer, since I don't use the exhaust speed (and have no idea how I could use it).

    Thank you
  2. jcsd
  3. Feb 9, 2012 #2
    What if you treated x and t as a variables....
  4. Feb 9, 2012 #3
    Seems like a wonderful idea and totally worked, that problem was so different from the others I've done in fluid mechanics... I have no idea that I needed to use x(t) in my dT/dt.

    Thank you Lawrence

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook