Transition predictions on hypersonic wing–body configuration with RANS-based models

Transition models based on the Reynolds-averaged Navier–Stokes equations have been widely applied in hypersonic vehicle design because they offer a balance between accuracy and computational efficiency. However, their validation for complex hypersonic configurations remains limited. In this study, the boundary-layer transition and aerodynamic heating characteristics of a hypersonic wing–body configuration are investigated, and the transition prediction performance of four representative transition models, namely the I–k–ω–γ, SST–γ, C–γ–Re_θ, and γ–Re_θt–f_Re models, is systematically assessed under complex three-dimensional flow conditions. Transition predictions are performed at Reynolds numbers of Re_∞ = 7.43 × 10⁶/m, 1.06 × 10⁷/m, and 1.27 × 10⁷/m, and at angles of attack of α = − 6°, 0°, and 6°, with detailed comparisons against wind-tunnel measurements. The results show that as Re_∞ increases, the triangular transition fronts characteristic on both the upper and lower surfaces expand, a trend consistently captured by all models. However, noticeable model-to-model differences remain. The prediction accuracy also deteriorates under nonzero angles of attack. At α = 6°, all models predict premature transition along the fuselage lower-surface centerline, a feature not observed in the experiments. This indicates a common limitation of existing transition models under large-angle, three-dimensional flow conditions. Overall, while current transition models are capable of capturing major aspects of boundary-layer transition in complex hypersonic configurations, further improvements are required to achieve more reliable predictions for realistic three-dimensional hypersonic flows.