[fluidmechanics]

Dear all

I am modeling laminar separation bubble over NACA0012 at Re=1.35E5. The airfoil experiences different A.O.A in a 2D problem (It is a static run). Yplus is round 1 and 4Eq. kwSST transition modeling ( Gamma and Theta) is used. I can capture separation bubble and reattachment and transition to turbulent flow. I have some questions which have confused me:

1- Why is it possible to capture separation bubble with steady solver, while as we know separation is a time dependent phenomenon?

2- What might be the reason that I can not capture trailing edge turbulent separation with both steady and unsteady solvers at AOA 6, 8 and 10 degree while experiments report turbulent separation point at x/c = 0.9, 0.8, 0.6!!!

I have also tried some fully turbulent flows using K-w SST with yplus=1, but no turbulent separation is observed in rather high A.O.A (X-wall shear flux does not vanish)!!

Experiment results are based on " An Experimental Investigation of Flow Over an Oscillating Airfoil" a MSC thesis 2004 at McGill University, Montreal, Quebec, Canada.

I have attached some contour and plots. Any comment or tutorial on how to capture separation point? Any idea?!

Regards

[fluidmechanics]

Any Idea of CFD experts about my separation problem recently posted?

Trivial ,but strange!!!!!!!!!!!!: