Abstract: For hypersonic vehicles, certain issues are crucial to the success of flight plans, including sudden increase in sur-face heat flux, rising aerodynamic drag coefficients, and changes in intake airflow caused by boundary layer transi-tion. Therefore, conducting in-depth research into boundary layer transition phenomena at hypersonic speeds is imperative. An improved k-ω-γ transition model is utilized to numerically simulate the transition characteristics of the Hypersonic Transition Research Vehicle (HyTRV) in this study. Initially, the results of the improved k-ω-γ transi-tion model for the datum condition of the HyTRV were compared with wind tunnel test and the eN method results, affirming that the transition model possesses a good predictive capability for the transition phenomena of the HyTRV configuration. Following this validation, the transition properties of the HyTRV configuration are probed, dis-closing the existence of streamwise vortex instability, secondary instability, and cross-flow instability on HyTRV, which induce boundary layer transitions. Finally, different transition configurations of HyTRV at various angles of attack are investigated. As the angle of attack increases, the streamwise vortex on the windward surface becomes compressed, and the streamwise vortex on the leeward surface moves upward. The deformation and movement of the streamwise vortex lead to changes in the transition configurations, which results in the merging of different transition areas.

Key words: transition mode, HyTRV, boundary layer transition, hypersonic, cross-flow