CFD Online Logo CFD Online URL
Home > Forums > Main CFD Forum

Calculating normalised Reynolds stress

Register Blogs Members List Search Today's Posts Mark Forums Read

LinkBack Thread Tools Display Modes
Old   August 30, 2011, 12:24
Default Calculating normalised Reynolds stress
New Member
Join Date: Aug 2011
Posts: 1
Rep Power: 0
cfd_newb is on a distinguished road
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: , is it simply a case of multiplying the fluctuating components in each specific direction to obtain the Reynolds stresses?

Thanks in advance!
cfd_newb is offline   Reply With Quote

Old   August 30, 2011, 14:10
Senior Member
Join Date: Mar 2009
Location: Washington, DC
Posts: 195
Rep Power: 10
mettler is on a distinguished road
I believe so. But, I am not sure you can do that with a compressible fluid (air)..even tho you state that the density is constant. You can check your values for the stresses to see which is dominant in the region of your flow. In the viscous sub-layer the laminar stress should dominate, and as you get closer to the centerline (further from the wall) the turbulent stress should dominate.
mettler is offline   Reply With Quote


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
post-processing utility R, calculating Reynolds stress tensor volker OpenFOAM Post-Processing 12 July 23, 2017 05:13
New implemented algebraic Reynolds stress model volker OpenFOAM 13 October 21, 2013 00:01
Reynolds Stress Models Jade M Main CFD Forum 0 April 21, 2010 16:38
Reynolds Stress Boundary Conditions tstorm FLUENT 0 July 27, 2009 14:44
Questions about the Reynolds stress model empirer2002 Main CFD Forum 1 January 5, 2006 08:37

All times are GMT -4. The time now is 20:34.