Standard-k-€ vs. low-Re-k-€
 

Hi,

I have a question about the difference in the calculation of the two different turbulence models Standard-k-€ (high-Re) and a low-Re model such as LaunderSharmak€.

I think I have read that the high-Re model is proned to calculate turbulent eddies bigger than they are in reality. Alleged due to great values of viscosity.
Because of that it is allegedly better to use a low-Re model such as LaunderSharmak€ to avoid this problem.

I'm not sure if this is right, so if anyone knows something more about that please let me know.

Best Regards,
tH3f0rC3

hi,

low-Re models are used in wall bounded flows with resolved boundary layer since turbulent fluctuations and therefore the turbulent viscosity (leads to a low Reynolds number) are damped near walls. So when to use a low-Re model depends on your case. Different turbulence models normally have different scopes and it is your job to find the right one for your case ;)

you can find some details in the Fröhlich BookLarge Eddy Simulation turbulenter Strömungen p. 52

gregor