Fully local transition closure model for hypersonic boundary layers considering crossflow effects

A computational fluid dynamics (CFD) compatible and fully local transition closure model is proposed for three-dimensional hypersonic boundary layers considering crossflow effects. The transition model is constructed with transport equations for laminar fluctuation viscosity and intermittency factor and coupled with Menter’s shear stress transport turbulence model. Based on the parameter analyses of the compressible Falkner–Skan–Cooke similarity solutions, the key factors for crossflow transition modeling, namely, the maximum crossflow velocity and the crossflow Reynolds number, are evaluated through new formulations based on local variables only. The new transition model is first tested against two axisymmetric cones to verify that the first and second modes are well modeled and not influenced by the newly established formulations for crossflow instability. Then, the HIFiRE-5 cases in quiet and noisy conditions and a circular cone at an angle of attack of 3 deg are selected to assess the performance of the present model for crossflow-induced transition. The numerical results show that the transition onset locations predicted by the present transition model are quite consistent with the experimental results, which indicates that the present transition model is capable of predicting crossflow-induced transition with a reasonable degree of accuracy and good compatibility with modern parallel CFD codes using local variables.