I assume this is a fairly straightforward question:
Can I change the turbulence model upon resuming a CFD analysis? What sort of disruptions could this cause? For example, I'm assuming the solver will need some iterations to do the auto-startup if switching from laminar to turbulent?
I have an scenario where the first part will be low flow (in the laminar region), but part two will include bursts of higher flow (into the low-Re region). I'm analyzing a scalar mixing problem. I have run part one in both laminar and low-Re turb mode and unfortunately my % volume scalar results are quite different at the end (~ 44% different). Therefore, I'm unsure about the accuracy of part two run in low-Re turb mode following part one.
Low Re model requires mesh really fine with Y+ values close to 1, since there are no wall functions. Are you sure about the mesh independence?