Numerical investigations of a repetitively pulsed MPD thruster



Performance of a repetitively pulsed self-field MPD thruster consisting of a flared anode and a short cathode was numerically investigated. For a time-averaged input power of 100 kW and argon propellant, thrust and thrust efficiency were surveyed for various discharge frequencies under the condition of continuous propellant injection and a constant discharge duty ratio of 0.5. The results suggest that thrust efficiency of repetitively pulsed discharge operation can be improved up to about 16% with increasing discharge frequency owing to a relatively high time-averaged electromagnetic thrust and an increase in aerodynamic thrust, and can surpass that of continuous discharge operation above 50 kHz. It is also shown that the frozen flow loss can be reduced by increasing discharge frequency, because the input power needed for reionization of the propellant can be suppressed. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.