Development of a local mathematical closure model for hypersonic transitional flows

In this research, a Computational Fluid Dynamics compatible transition closure model for high-speed laminar-to-turbulent transitional flows is formulated with consideration of the analysis results by stability theory, which contains two transport equations to describe the transition mechanism using local variables. In addition, the eddy viscosity of laminar fluctuations and intermittency factor are chosen to be the characteristic parameter and transported in the present model. Accounting for the dominant instability modes at supersonic/hypersonic conditions, the first- and second- modes are modeled using local variables through the analysis of laminar self-similar boundary layers. Then, the present transition model is applied with compressibility corrected k-ω shear stress transport turbulence model. In the end, several sets of well-documented flow cases are chosen to validate the present transition model, and the yielding results are in satisfactory accord with experimental data. Proven by the numerical tests, the present model is capable of predicting the first and second Mack instability modes and supersonic laminar separation.