I believe that this question might be more towards OpenFoam use than SIMSCALE but I figured I would swing it by the community and see if you could help. I am having some issues related to convergence of a K-W SST model and am in the process of checking my BCs and ICs. So far I was having good convergences in laminar models and so I believe that the BCs and ICs not related to turbulence are probably fine. This leads me to examine my K(initial) and W(initial):
The first question I have is, what is your approach to obtaining a value that would be good for the whole domain? Do you take your lengths from an specific location? Calculate values at different points and try to average them? I am more used to prescribing the values at specific locations (BCs) and allowing for the ICs to be calculated automatically.
My second question is what approach do you use to obtain the actual values for K and W? I generally follow something like what is shown in the webpage below:
k = (3/2)(UI)^2,
Where U would be velocity at the inlet, L = inlet diameter
and v the kinematic viscosity is given by the material.
For omega, I would then use:
w = sqrt(k)/l,
l = 0.038*dh
where dh is
the Inlet diameter again.
I have also tried with
w = Cμ^(-1/4)*sqrt(k)/l,
Cμ = 0.09
However if I use these values it seems to affect my simulation and give a worse convergence than if I leave the default values.