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

Scaling/non-dimensional navier-stokes

  1. Apr 27, 2008 #1
    Hey guys,

    Just trying to non-dimensionalise the navier stokes equation. We were taught how to do it when you scale x,y,z with one reference length L....just wondering how to do it if I scale x,y,z with a,b,c respectively.

    Edit - this is what I already know http://www.mme.tcd.ie/~craigm/Cnotes/4b6/nodes/week1.php#SECTION00080000000000000000 [Broken] they use one reference length L to scale as well
    Last edited by a moderator: May 3, 2017
  2. jcsd
  3. Apr 28, 2008 #2


    User Avatar
    Science Advisor

    Why would you want to non-dimensionalize with 3 different reference lengths? In fact, I don't even think that you 'can' do this. When you non-dimensionalize, you only get a 1/Re because there is a 1/L in every term.

    Maybe I am misunderstanding your problem, perhaps you can elaborate a little more on what you mean by scaling with a,b, and c?
  4. Aug 14, 2009 #3
    Yes, you can. It is done in climate science.

    http://www.mne.psu.edu/cimbala/me33web_Fall_2005/Lectures/Nondimensionalization_of_NS_equation.pdf [Broken]
    Last edited by a moderator: May 4, 2017
  5. Aug 14, 2009 #4
    I don't believe this would be coordinate invarant, would it?
  6. Aug 16, 2009 #5
    I'm sorry, I'm not sure what that means. The transformations do seem to get rid of the units though.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook