γ-Re_θ model research for high-speed boundary layer transition

This study evaluates the application of Menter's γ-Re_θt transition model with a RANS solver for transition prediction on super-sonic and hypersonic flows. The transition onset position and transition length are approached by utilizing two transport equations for local Reynolds number and intermittency. The present work expands upon the transition prediction methodology by validating the model against wide range of Reynolds number, three-dimensional flows in the form of cones at angle of attack and bluntness effects. Test cases including Mach 3.5 cone with free stream unit Reynolds numbers from 2.8E7 to 7.8E7, Mach 5.91 flared cone and cone with 0 to 4deg angle of attack and Mach 7.16 cone with 3 nose radius have been performed. Comparisons for skin-friction coefficient and heat transfer with experimental data are presented. Results show that this model predicts the correct trends with respect to angle of attack and bluntness effects. It is found that the agreement between simulation and measurements varies better from small Reynolds number to large cases and .However there still are few limits in this very model in predicting supersonic or hypersonic transition process.