MHD Simulation and Thermal Design of an MPD Thruster

Abstract

For a 500-to-900-kW-class steady-state self-field magnetoplasmadynamic (MPD) thruster, the thermal design is conducted with a combination of magnetohydrodynamic (MHD) and thermal analyses, where a heat flux evaluated from the MHD analysis is imposed on the electrode as a boundary condition in the thermal analysis. The increase in anode-to-cathode radius ratio improves the thrust performance, but can simultaneously raise the temperature locally at the anode exit edge and the cathode tip due to the concentration of the discharge current and/or the insufficient heat removal. It is suggested, however, that a thruster without electrode melting should be realizable even at such a high input power by setting an appropriate cathode radius and enhancing heat removal from the electrodes by means of heat pipe, although the achievable performance of the thruster depends on the assumption of the temperature of cathode root.