A pressure-based method for computing electron fluid flows in hybrid model for Hall-effect thrusters

Abstract

An axisymmetric hybrid model solving magnetized electron flow governing equations for Hall-effect thruster plasma dynamics in the discharge channel and the near-plume region is presented, using the pressure-implicit split operator algorithm, a form of the pressure-based method. A method for directly solving the electron momentum equation, without the explicit form of the generalized Ohm's law, is introduced. The electric potential equation is obtained by substituting the Rhie–Chow interpolation formula into the current conservation equation, which is derived by applying the analogy between incompressible inviscid flow and the electron fluid equations. In this study, inertialess electrons are assumed for the purpose of validation through the comparison of numerical methods and analysis of the plasma response under various physical parameters. Computed plasma and performance parameters show agreement with the results from other hybrid models and measured performance data. The cathode is modeled by assigning the plasma density measured at the cathode orifice entrance to the node points of the particle-in-cell mesh that constitutes the cathode boundary. A detailed analysis is conducted to examine the plasma response to the variations in the cathode plasma density.