Performance Modeling of a Thrust Vectoring Device for Hall Effect Thrusters

Abstract

The ability to control the thrust vector direction on electric propulsion devices opens new possibilities for mission optimization. The addition of an external magnetic steering system and the nonsymmetric localized injection of propellant have been proposed to deviate the ion beam of a PPS®1350 Hall effect thruster. A two-dimensional hybrid model has been used to evaluate the preliminary design. Simulated results suggest the ion beam angular distributions may be varied in the range of 10 deg by changing the current in the external steering coils. However, a magnetic topography with field lines directly connected from the outer steering pole to the anode leads to a reduction of the Hall effect thruster performance. The erosion of the walls increases drastically as a function of the magnetic lens orientation (6 mm for 1000 h of thruster operation for high coil currents in the external coils). A localized axial injection of atoms has a positive effect on the steering angle of the ion beam (a few degrees), but exhibits additional erosion of approximately 10―15%. Qualitative comparisons with experimental results confirm the simulated trends.