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 cfd_newb August 30, 2011 12:24

Calculating normalised Reynolds stress

Hi - first post, but been lurking on the forums a while! I wonder if I could get some help in simple terms! I'm completely stuck on what I guess should be a simple problem. I've done a search on here, and am still stuck as my results aren't at all what I'm expecting...

I have some Fortran CFD code, and am running incompressible 2D and 3D simulations from it. Ignoring the 3D simulations for now, I have a problem in results generation (post-processing) that I'm trying to figure out.
I want to have plots of normalised Reynolds stress in uu and vv axis for particular points in the simulation. I have output, at every 100 iterations, the values at the relevant points for u,v,density,energy,pressure. I have determined a time-averaged mean for each of these at each point, and can determine the fluctuations quite straight-forwardly from the data. (again, the fluctuations are taken as a time-averaged value for all fluctuations at each point).

The fluid itself in free-space has a constant density (it's air). So looking at this page: http://en.wikipedia.org/wiki/Reynolds_stress , is it simply a case of multiplying the fluctuating components in each specific direction to obtain the Reynolds stresses?