limited turbulent viscosity ratio

Volker Pawlik

Hello cfd-community,

actually I am working on a problem with a - for me - very high Re-numer (about 1E6). Since I am accustomed to lower numbers I am a little uncertain about how to handle some of the problems which appeared:

1.) During the solving process the turblulent vicosity ratio was limited just inside the area of interest. When I estimate the turbulent intensity I by I=0.16*Re^(-0.125) it gave similar values to what Fluent reported. So my question is whether it is reasonable to increase the default limit due to the high Re to avoid hitting the limit or whether s.th else could be wrong (may be it is related with 2.

2.) To achieve 30 < y+ < 60 I would need too much cells. Sung-Eun Kim from Fluent mentioned in the past that it is ok for high Re flows to increase the upper limit. I followed the advice and generated cells to achieve y+ about 500. The question is: Is s.o. able to assess, whether 500 is still ok for such a Re? (the domain is similar to a t-pipe)

Volker