[Hr_kules]

Hey guys,

i am running the k omega SST model for a series of simulations and in my old lecture notes was the recommendation that if heat transfer is important one should use the k omega SST with a y+ of 1, 10-20 number of layers and growth rate of 1.2. This works so far, but i need/want to understand my simulation better.

For the first layer height i used the calculator from this website https://www.cfd-online.com/Tools/yplus.php. I can mesh that with snappyHexMesh and Gmsh, no problem whatsoever, however if i run my simulation the y plus function object prints:
patch wallDeveloped y+ : min = 0.0048604, max = 0.00530782, average = 0.00514233

How can this happen if the y+ used to calculate the height was 1?
How do wallfunction for k, omega and alphaT come into place? Are they even needed? Or should i leave them out? The results are quite good and i usually don't touch a running system, however i want to drive deeper and understand what i am doing.

Lucking forward to hear some suggestions!