Numerical analysis of MPD arcs for plasma acceleration

Abstract

The characteristics of the arc region of the plasma thruster are investigated from the numerical solutions of the coupled MHD equations and physical properties are studied as system parameters. In this specified analytical model, the flow is assumed to be two-dimensional and steady with all other realistic effects included: the Hall effect, ion slip, dissipations such as viscosity, thermal conductivity, and electrical resistivity. The generalized Ohm``s Law is considered here to include the Hall and ion slip terms. And we also study the ideal case neglecting dissipations except electrical resistivity. The results of the conducted analysis indicate the concentration of current and temperature rise at the trailing edge of anode. The Hall current exerts the harmful effects in lowering the thrust efficiency as well as erosions of the electrodes. The erosion of the cathode can be reduced by using gases of large specific heat ratio as the propellant. The thermal diffusion is found to play a positive role in raising the thrust efficiency and preventing erosion of electrodes.