Microwave-Driven Air Plasma Studies for Drag Reduction and Power Extraction in Supersonic Air

摘要

Program involving modeling and experiment to explore the utility of plasmas and magnetohydrodynamics (MHD) for aerodynamic applications. Anomalous behavior of shocks on weakly ionized plasmas has been explained in terms of conventional gas dynamics with temperature gradients. Theoretical and computational models have been developed for plasma aerodynamics and nonequilibrium MHD. Models include a new theory of nonequilibrium dissociation and vibrational relaxation and kinetics of plasmas generated by electron beams and high-voltage nanosecond pulses. Aerodynamic steering using plasma energy addition has been explored using the newly developed microwave-driven supersonic plasma wind tunnel. Potential performance of hypersonic MHD devices with electron beam ionization has been outlined. Plasma and MHD control of hypersonic flows and scramjet inlets was studied. On-ramp MHD device with ionization by electron beams was shown to be capable of maintaining the shock-on-lip condition at Mach numbers higher than the design one, while generating net power. For mass capture increase at Mach numbers lower than the design one, a new concept of virtual cowl was proposed and tentatively studied. In preparation for experimental studies of MHD control of cold-air high-speed flows, ionization by repetitive high-voltage nanosecond pulses was studied theoretically, and a plasma sustained by such pulses was made operational.