Hi Which is the best choice between k-eps (extended wall function), k-omegaSST and Spalart-Allmaras for a transonic flow with shock waves? And what are the right values for yplus for each model? Thank you

Did you have a look at recent AIAA conference publication abstracts ? Many different models have been applied to study transonic flow.

I heard, that the choose of turbulence model is not so important in problems with shock waves, because the energy in a shock wave is very higher than the turbulent energy.