Omega-based:
All omega-based models are continuous (can be integrated to wall without damping functions), so doesn’t matter what y+ there will be k, omega, nut (if use Spalding wall function) values on the wall patches. But, there is no general way of applying a turbulence model with the first cell in y+=5-30 due to large variations in different turbulence source terms. It is recommended that you use either y+=1 or y+>30:
- y+<5 is (generally) acceptable, and you can’t possibly have y+=1 everywhere. Stagnation points and regions with flow separations can go below unity. I always use y+<5 in design when I don’t wish to use y+>30, but 99% of the time I use y+>30. There are always regions where y+ is less than 30, but you should keep the area as small as possible.
- You don’t need to use y+<1 in non-transitional RANS.
Epsilon-based:
StandardKE and realizableKE ( in their original forms) are high Reynolds number turbulence models. Use y+>30. Some codes allow high-Re models to integrate to wall, but there is no such wall treatment on SimScale.
RealiableKE is the most suitable turbulence model available on SimScale for your purpose. It yields relatively low nut in vortex cores, doesn’t have nut build-up in stagnation points, and is very good in strong adverse pressure gradient.