A RANS model correction on unphysical over-prediction of turbulent quantities across shock wave

The unphysical increase of turbulent quantities in turbulence model induced by shock wave in simulations of hypersonic flows and its influence on the aerothermal prediction are studied. Using k-ω SST model, numerical experiments on the hypersonic flow over a blunt body indicate that the strong detached shock wave will result in serious unphysical increase of turbulent quantities and the increase magnitudes are closely related to the mesh scales near the shock wave. This phenomenon could generally cause an over-prediction of the aerothermal prediction. To eliminate this unphysical phenomenon and enhance the accuracy of aerothermal prediction, a new correction model for current k-ω SST model is established, which includes two parts: a shock wave detector to identify the location of shock wave and a damping function for the production terms in turbulent transport equations. Finally, the modified k-ω SST model using the correction model is applied to two types of hypersonic flows. Numerical results prove that the correction model can effectively eliminate the unphysical increase of turbulent quantities around the shock wave and meanwhile does not affect the normal development of turbulent quantities inside boundary layer. Through the correction model, the accuracy of aerothermal prediction is remarkably improved.