Professor M. Pino Martin
Turbulent Hypersonic Flows: Physics and Simulation
We are using direct and large-eddy simulations to study hypersonic turbulent flows with the goal of understanding the interaction of turbulence with shock waves, finite-rate reactions, surface catalysis and ablation, and radiation. To do this we have developed numerical methods for low-dissipation, high-bandwidth and shock capturing, as well as implicit time integration methods, initialization procedures, and methodologies to prescribe continuous inflow conditions. We are now applying these methods to problems of interest to atmospheric hypersonic flight, supersonic combustion and access to space.
Some of the flows that we have simulated include shock wave-turbulent boundary layer interactions. The resulting data are being validated against experiments that are designed for this purpose. So far, we have obtained remarkable agreement between the simulation and experiments in mean flow variables, turbulence amplification, structure angle, and the size of the separation zone. Currently, we are studying the unsteady motion of the shock and its effect on the wall-pressure fluctuations and heat transfer. Another aspect that we are investigating is the characterization of turbulent structures, which is relevant to aspects of flow control. We find that increasing the freestream Mach number results in structures that are shorter and inclined at higher angles. This is due to the higher number density of shocklets that are found with increasing freestream Mach number. We are using simulation data to study various other problems including the coupling of finite-rate reacti
ons and surface chemistry with turbulence.