Simultaneous Calibration of Anomalous Electron Collision Frequency and Anomalous Electron Heating in a Hall Thruster Simulation

This paper presents a novel method of calibrating anomalous electron phenomena in fluid simulations of Hall thrusters. Specifically, this paper presents methods to calibrate the anomalous electron collision frequency, ν_ea, with measurements of the azimuthal electron drift velocity, u_eθ, and to calibrate the anomalous electron heating, Q_ea, with measurements of the electron temperature, T_e. These methods are implemented in the Hall2De simulation code with incoherent laser Thomson scattering measurements of the axial profiles u_eθ and T_e along the channel centerline of a Hall thruster. Two primary simulations are considered, one that calibrates only ν_ea and another that simultaneously calibrates ν_ea and Q_ea. In addition, auxiliary simulations are calibrated using the uncertainty bounds of the measured u_eθ and T_e axial profiles that produce corresponding uncertainties in the axial profiles of ν_ea and Q_ea. We find that both primary simulations exhibit a sharp local minimum in ν_ea at the axial location corresponding to the maximum of u_eθ. It is found that uncertainties in u_eθ produce large uncertainties in the downstream portion of the ν_ea profile. However, when only uncertainties in T_e are considered, there is a measurable difference in the ν_ea profiles between the two primary simulations. Lastly, while there is significant ambiguity in the calibrated profile of Q_ea, the calibrated profile shows significant deviation from the phenomenological model of Q_ea typically used in Hall thruster fluid simulations.