Prediction of Crossflow Transition using γ Transition Model Coupled with Reynolds Stress Transport Turbulence Model

This study presents an enhanced second-order closure transition model, SSG/LRR-ω-γ, incorporating crossflow transition effects for improved prediction of laminar–turbulent transition in three-dimensional boundary layers. The original formulation couples the SSG/LRR-ω Reynolds stress model with Menter’s one-equation γ transition model to address streamwise instabilities. To extend its capabilities, a local helicity-based criterion is introduced to account for crossflow-induced transition. The modified model is assessed using two benchmark configurations: the NLF(2)-0415 infinite swept wing and the DLR 6:1 prolate spheroid, across a range of operating conditions. A grid sensitivity analysis is also performed to ensure numerical robustness. Results demonstrate that the crossflow model accurately captures crossflow-induced transition and provides improved agreement with experimental data compared to the original streamwise-only formulation.