The Role of Three-Dimensional Shock Wave Interaction in the Complex Hypersonic Heating

A shock-expansion tube/tunnel is a ground-based test facility to generate hypervelocity test flows for the study of atmospheric reentry physics. Such a high enthalpy test flow features thermochemically non-equilibrium which may lead to critical difficulties in flow diagnostics and measurements. In addition, the test time of such an impulse facility is extremely short which implies a requirement of transducers with high-frequency response capability for model tests or flow diagnostics. In the present work, computations for non-equilibrium reacting flow are conducted to diagnose the key flow parameters and evaluate the test flow for facility upgrading. A conic nozzle is appended to the original facility and to obtain a larger test section and larger Mach numbers. Further experiments are conducted to visualize the overall flow structures over the test models by self-illumination of radicals at high-energy states post strong shock waves. The heat flux at the stagnation point is measured with specially designed thermal couples