Shock Control and Power Extraction by MHD Processes in Hypersonic Air Flow

摘要

This project was a theoretical and experimental research effort on the use of MHD body forces and plasmas for boundary layer control and power extraction in supersonic flow, and on the development of new diagnostics for plasmas and for high-speed flows. The first part of this final report addresses MHD processes for control and power extraction. This section includes the constricted DC driven 'snowplow arc' discharge that can potentially be used to accelerate the boundary layer for suppression of separation, volumetric MHD for power extraction, and volumetric MHD for flow control. In order to accomplish volumetric MHD in cold air, a high repetition rate, short pulse sustainer concept is developed and applied for the first demonstration of power extraction from cold supersonic air. The following section addresses non MHD plasma methods of flow control and power extraction, particularly through the use of a dielectric barrier discharge and through a new pulse sustained thermionic power generator embedded into the hot walls of the vehicle engine. Finally, two new diagnostic methods are introduced in the third section: magnetically modulated microwave attenuation for the measurement of electron number density and electron collision frequency, and Radar REMPI for the localized measurement of flow velocity.