Prediction of Hypersonic Boundary-Layer Transition in Wind Tunnels and Flight

Accurate forecasting of boundary-layer transition is critical for hypersonic vehicle design as transition significantly affects aerodynamic drag and heating. The ultimate goal of this SBIR project is to assemble easy-to-use, accurate, and efficient tools validated via ground-test data and ready to be applied for flight to predict transition on hypersonic vehicles. During phase I, algorithms were developed to estimate the onset of 2nd mode dominated transition in large-scale facilities. During phase II, this framework will be advanced to include relevant physics such as freestream disturbances, non-equilibrium thermochemistry, ablation-induced blowing, and surface roughness to enable predictions of 3D boundary layers that can have crossflow, multiple modes, secondary or subcritical instabilities, and other phenomena that lead to transition. Receptivity computations will be performed to account for various relevant thermo-physico-chemical processes with systematic validation occurring via available ground and flight data. Additionally, the amplitude-based receptivity model from Marineau et al. will be demonstrated on several configurations and compared with high-fidelity simulations. The integrated physics-based and rigorously validated stability toolbox will be delivered to the government in a format ready for integration with a number of existing hypersonic simulation tools utilized by the sponsor, and onsite training and documentation will be provided.