When I computed laminar-turbulent transition on 2D airfoil, I have got unrealistic transition at distance 10 times shorter than in reality. Which turbulence model constants to change? I would like tune k-omega model to my flow cases.

i think you have to use sst k-w model with transitional flow, it gives a better results than Standard k-w. I use for all my computations this model and there is a good correlation with experimental data