Current density on cathode surface of MPD thrusters

A magnetoplasmadynamic thruster formulation involving coupled aerothermodynamic-electromagnetic equations and including viscous effects is developed and solved. The effect of various input parameters on the radial current density distribution at the longitudinal cathode surface is studied. In general, radial current concentrations are found at the upstream and downstream ends of the cathode. The upstream current concentration is larger in magnitude and is attributed to large values of the Hall parameter. Higher inlet velocities and densities, lower inlet temperatures and propellants of lower molecular weight, all reduce the upstream current concentration. The downstream current concentration is attributed to large values of the inlet velocity.