I've tried to run some 3D simu
I've tried to run some 3D simulations with a Reynolds stress model lately, but they will not converge. I've played around with the settings and variables but the simulations remains unstable. However, with the kepsilon model the simulations converges nicely. Have anyone else had succees with the RSM, or am I doing something utterly wrong?

It should work without problem
It should work without problems. If you are running something relatively small and simple I wouldn't mind having a look, just to make sure RSTM is still fine.
Hrv 
It's a small case where two sq
It's a small case where two square ducts, each of them with dimensions 0.1*0.1*1 (m), are joined together in a 90 degree bend. Air is flowing through at a Reynolds number of 100,000. The turbulence intensity, and the turbulent length scales compared to the outer dimensions, are both assumed to be 10 %.
The kEpsilon and RNGkEpsilon works well on this geometry, but I cannot obtain a solution with the LRR or LaunderGibsonRSTM models. 

Steve,
I don't think you ma
Steve,
I don't think you managed to attach the file. Hrv 
Hi,
Im a beginner att openF
Hi,
Im a beginner att openFOAM but I have tried the turbmodels you mension and I have had a similar problem which i got thru by having a epsilon value 3 times as big as when I used the kepsilon models. /erik 
I'll try again:)
Here is a

I don't see a problem: it conv
I don't see a problem: it converges monotonically. This is what I did:
 run 100 iterations with kepsilon  calculated Reynolds stress using R  restarted with LaunderReeceRodi RSTM. Converges smoothly with no trouble. I can either give in normal stress only at the inlet of the full equilibrium R from the kepsilon model. A few comments:  your numerics is rubbish: you should try using second order  if you try to start up LRR from the beginning it blows up because of epsilon. You should really start kepsilon and restart; otherwise you will have fun trying to set up underrelaxation coefficients  at the end of the residual graph you start hitting solver convergence tolerances: hence the plateau  I can make this even better using my fixedMeanValue outlet b.c.: makes it prettier close to the outlet http://www.cfdonline.com/OpenFOAM_D...ges/1/3006.jpg Hrv 
Hi Hrvoje
I didn't now abou
Hi Hrvoje
I didn't now about the "R" function. When I followed you steps the solution converged without problem. Thank you Steve 
1 Attachment(s)
Hi
I try to use LRR for my simulation. I'm simulating an atmospheric boundary layer, but my result with it are completely different from the same case with keps model. Post my case. Thanks 
Quote:
Could you please provide an fvSchemes and fvSolution that aren't "rubbish"? I'm not very wellversed in numerical methods (yet!) and would like to get a better idea of what 'good' settings for LRR are. Thanks! 
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