Numerical Investigation of Plasma Behavior and Anode Sheath in a Magnetoplasmadynamic Thruster

The Roe-Harten-Lax-van Leer and Einfeldt hybrid flux method has been used to model the phenomena occurring in the Princeton benchmark Self-field MagnetoPlasmaDynamic thruster. The eigensystem has been computed by Powell's technique, and an optimized monotonic upstream-centered scheme for conservation laws has been applied to achieve a high-resolution method. Also, a one-dimensional description of a collisionless sheath has been taken into account to predict the anode fall voltage. In this study, the argon plasma propellant, with mass flow rate of 4g/s, has been considered to be in thermal and chemical nonequilibrium states. For the discharge current of 16kA, the values of fall voltage, electric field, and Hall parameter have been respectively predicted about 3.75V, 5.5MV/m, and 1 at the anode midlip. The simulated hot spots near the anode and cathode, the inner flow of ions around the cathode, and the exhaust plume structure have been captured in good agreement with the other corresponding experimental and numerical results. Moreover, the anode fall voltages have been obtained by less than 10.5% difference compared with the measured values. Furthermore, the inverse dependence between the anode fall and current density has been numerically predicted well in comparison with the measurements.