Bayesian inference is applied to calibrate and quantify prediction uncertainty in a coupled multi-component Hall thruster model. The model consists of cathode, discharge, and plume sub-models and outputs thruster performance metrics, one-dimensional plasma properties, and the angular distribution of the current density in the plume. The simulated thrusters include a magnetically shielded thruster operating on krypton, the H9, and an unshielded thruster operating on xenon, the SPT-100, at pressures between 4.3--43 $\mu$Torr-Kr and 1.7--80 $\mu$Torr-Xe, respectively. After calibration, the model captures key pressure-related trends, including changes in thrust and upstream shifts in the ion acceleration region. Furthermore, the model exhibits predictive accuracy to within 10\% when evaluated on flow rates and pressures not included in the training data, and can predict some performance characteristics across test facilities to within the same range of conditions. Compared to a previous model calibrated on some of the same data [Eckels et al. 2024], the model reduced predictive errors in thrust and discharge current by greater than 50%. An extrapolation to on-orbit performance is performed with an error of 9%, capturing trends in discharge current but not thrust. These findings are discussed in the context of using data for predictive Hall thruster modeling in the presence of facility effects.
翻译:本研究应用贝叶斯推断方法,对耦合多组分霍尔推力器模型进行校准与预测不确定性量化。该模型由阴极、放电和羽流子模型构成,可输出推力器性能指标、一维等离子体特性以及羽流中电流密度的角向分布。模拟对象包括以氪工质运行的磁屏蔽推力器H9,以及以氙工质运行的非屏蔽推力器SPT-100,其背景压力范围分别为4.3--43 $\mu$Torr-Kr和1.7--80 $\mu$Torr-Xe。校准后的模型能够捕捉关键的压力相关趋势,包括推力变化和离子加速区的上游迁移。此外,在未参与训练数据的流量与压力条件下进行评估时,模型展现出10%以内的预测精度,并能在相同条件范围内跨试验设施预测部分性能特征。与先前基于部分相同数据校准的模型[Eckels et al. 2024]相比,本模型将推力与放电电流的预测误差降低了50%以上。对在轨性能的外推预测误差为9%,虽能捕捉放电电流趋势但未能准确预测推力变化。本文结合试验设施效应的影响,对上述结果在霍尔推力器预测建模中的数据应用价值进行了讨论。