Near Surface Flow Control and Electrical Power Extraction Using Magnetohydrodynamics in High Mach Number Flight

An experimental study focusing on demonstration of feasibility of magnetohydrodynamic (MHD) power generation in cold supersonic air flows is proposed. The experimental facility to be used for these studies (low-temperature nonequilibrium plasma / MHD wind tunnel) is currently under operation at Ohio State. The primary objective of the proposed research is to demonstrate electrical power generation using cold nitrogen and air flows (M=3-4) seeded with easily ionizable hydrocarbon vapor (TMAE) at a few ten to a few hundred ppm level. Ionization in supersonic flows will be produced using a high-voltage, high repetition rate, nanosecond pulse generator. Electrical conductivity, Hall parameter, and cathode voltage fall in the repetitively pulsed discharge will also be measured. Generated electrical power will be measured at different TMAE concentrations, Mach numbers, and load parameters. The proposed study will determine applicability of on-board MHD power generation using lightweight permanent magnets. Preliminary experiments in unseeded M=3 nitrogen flows demonstrated MHD power generation at ~1 mW levels. The power is expected to significantly increase with the flow conductivity produced by a repetitively pulsed discharge in TMAE-seeded flows. The results will have direct impact on development of a nonequilibrium air MHD power generation module for in-flight operation using lightweight magnets.