Comparison of Simulated Magnetoplasmadynamic Thruster Flowfields to Experimental Measurements

The flowfield of a magnetoplasmadynamic thruster was simulated numerically using an advanced code specifically developed for this purpose, and the results were compared to experimental measurements, to validate the code and obtain insight into underlying physical processes. The thruster chosen was the full-scale benchmark thruster because it has been the subject of many experimental studies. The parallelized axisymmetric code featured detailed physical models and a finite volume formulation that allowed for nonorthogonal grids. Flowfield properties, such as electron density, velocity, current density, electron temperature, ionization fraction, and mass and momentum flux, as well as thrust, compared favorably with existing data. The simulation provided insight into some aspects of thruster operation, such as the weak role of the anode geometry in affecting the thrust, the predominantly electromagnetic nature of the thrust at nominal operating conditions, and the importance of the near-cathode region in energy dissipation. The simulated structure of the flow was found to embody a number of photographically recorded features of the actual discharge.