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

Turbulent gas flow

  1. Mar 10, 2007 #1
    Hello

    Im currently looking at turbulent gas flow in circular pipe sections by calculating the Reynolds the number. Does the Reynolds eqution hold for say flow of an ideal gas - air as it does for a real fluid say water.

    This may sound like a stupid question and I supose I've got my head in a twist between the difference of a real fluid and a ideal gas, but I would like to know if I can calculate the reynolds number for a gas - in the same way I would say water through a pipe.

    Any help would be greatly appreciated

    A very confused Mancunian
     
  2. jcsd
  3. Mar 10, 2007 #2

    Astronuc

    User Avatar

    Staff: Mentor

  4. Mar 10, 2007 #3

    FredGarvin

    User Avatar
    Science Advisor

    Reynolds number definition does not change due to fluid state that I have ever seen. The trick comes in, when dealing with gases, is getting accurate property values. An ideal gas is pretty easy, but it gets tricky when going away from the ideal model and you have to start correcting for pressure (compressibility) and temperature. At work, our aero guys have proprietary aero-thermo codes specifically for calculating properties that are non ideal in our engine decks.
     
  5. Apr 25, 2009 #4
    Hello Mancunian
    don't be confused, Gases and fluids are measured equally in their way of getting turbulent or remaining laminar... That is hydrodynamics, yet remarcs of non ideal gases (electrically?) or ideal fluids (non -Stokes) remain of consequence.
    greetings Janm
     
  6. May 16, 2009 #5
    Hello turbulence freaks
    You have to admit that yesterday waterballet is not only a olympic game anymore but entried entertainment. I know you want to hear here about turbulent gas flow, more difficult to see (coloured gasses?) then turbulent water (still remaining best drawing of L. daVinci) yet hanging water bassins brought to the public in Russia as an experiment for multimedia...
    I was astounded...
    And for calculating reynolds number for gasses: The Reynolds number is a dimensionless number. The way I was tought about that is: you can make a model with the same Reynolds number with very varied number of dimensions but if the Reynolds number is the same you get the transition of laminar to turbulent or the other way around in the same way as a model which uses the whole North Sea saying Norway has won...
    Sorry for eventually poetic changes, but I am still impressed of the ESC...
    greetings Janm
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?