[Suliman]

Hi

I have a question about the k-Epsilon model. It says that this model predicts excessive turbulent kinetic energy k at stagnation points! And that is why K-omega SST uses limiters of the production term to limit this problem. Can anyone elaborate on this point? Why k-Epsilon predicts high k at stagnation points? K should be low!

[sbaffini]

Give a look here:

https://www.sharcnet.ca/Software/Ans...wo_eq_mod.html

equation 4-383 and the Kato-Launder modification. Basically, near stagnation points you still have high derivatives, which enter the k production term, which is non negative for incompressible flows.

You can see it as a Boussinesque hypothesis flaw rather than a problem of a specific model.