Drag and thermal management are key aspects of hypersonic flight. One method to reduce frictional and thermal loads is to prevent boundary layer transition to turbulence. On the other hand, turbulence is often inevitable or desired for efficient ablation and propulsion. Our research interests include fundamental understanding and control of transitional and turbulent flows, with an emphasis on chemical, mechanical and thermal nonequilibrium effects and surface interactions. Example applications include ablation, roughness, entropy layer effects and radiation, which alter heat transfer, skin friction and vehicle performance. Our studies include physical modeling, advanced experimentation, and large-scale computation. To learn more about our research, see our publications or contact us directly.
Many of the key flow quantities of interest have proven difficult to measure, e.g., the turbulent heat flux. The National Aerothermochemistry Laboratory (NAL) was created to meet this need. This laboratory houses numerous world class facilities, instrumentation and numerical methods. For more information about the laboratory, see the Laboratory Link. Many of the available facilities and instruments are specialized. For example, we are working closely with the North group to develop the vibrationally excited nitric oxide monitoring (VENOM) system, which is optical diagnostic to simultaneously and instantaneously measure the velocity and temperature to quantify the turbulent heat flux. We are also developing a stereoscopic, dual-plane extension of this system (VENOM2) to significnatly extend the capability..
Modern computational and experimental tools have advanced to the point where they enable new opportunities in flow control, which may provide solutions to important technological challenges. Our flow control research is divided along two lines. In one, we are examining the role of mechanical non-equilibrium on the modification of turbulence and secondary flow with applications in hypersonic external aerodynamics and scramjet combustion. In the second, we are quantifying underlying flow mechanisms associated with dynamic stall on helicopter rotors.