With the increased interest in electric propulsion for space applications, a wide variety of electric thrusters have emerged. For many years, Hall effect thrusters have been the selected technology to sustain observation and telecommunication satellites thanks to their advantageous service lifetime, their high specific impulse and high power to thrust ratio. Despite several studies on the topic, the Hall thruster electric discharge remains still poorly understood. With the increase of available computing resources, numerical simulation becomes an interesting tool in order to explain some complex plasma phenomena. In this paper, a fluid model for plasma flows is presented for the numerical simulation of space thrusters. Fluid solvers often exhibit strong hypotheses on electron dynamics via the drift-diffusion approximation. Some of them use a quasi-neutral assumption for the electric field which is not adapted near walls due to the presence of sheaths. In the present model, all these simplifications are removed and the full set of plasma equations is considered for the simulation of low-temperature plasma flows inside a Hall thruster chamber. This model is implemented in the unstructured industrial solver AVIP, efficient on large clusters and adapted to complex geometries. Electrical sheaths are taken into account as well as magnetic field and majors collision processes. A particular attention is paid on a precise expression of the different source terms for elastic an inelastic processes. The whole system of equations with adapted boundary conditions is challenged with a simulation of a realistic 2D r-z Hall thruster configuration. The full-fluid simulation exhibits a correct behavior of plasma characteristics inside a Hall effect thruster. Comparisons with results from the literature exhibit a good ability of AVIP to model the plasma inside the ionization chamber. Finally a specific attention was brought to the analysis of the thruster performances.

中文翻译：

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专用于非结构化高性能计算求解器中的空间推进的低温等离子体流的流体形式

随着对空间应用电力推进的兴趣增加，出现了各种各样的电动推进器。多年来，霍尔效应推进器凭借其优越的使用寿命、高比冲和高功率推力比，一直是维持观测和电信卫星的首选技术。尽管对该主题进行了多项研究，但霍尔推进器放电仍然知之甚少。随着可用计算资源的增加，数值模拟成为解释一些复杂等离子体现象的有趣工具。在本文中，提出了等离子体流的流体模型，用于空间推进器的数值模拟。流体求解器通常通过漂移扩散近似对电子动力学表现出强烈的假设。其中一些对电场使用准中性假设，由于护套的存在，该假设不适用于靠近壁的电场。在本模型中，所有这些简化都被删除，并考虑了全套等离子体方程来模拟霍尔推进器室内的低温等离子体流。该模型在非结构化工业求解器 AVIP 中实现，在大型集群上高效并适用于复杂的几何形状。考虑到电护套以及磁场和主要碰撞过程。特别注意弹性和非弹性过程的不同源项的精确表达。具有自适应边界条件的整个方程系统受到现实 2D rz 霍尔推进器配置模拟的挑战。全流体模拟展示了霍尔效应推进器内等离子体特性的正确行为。与文献结果的比较表明 AVIP 能够很好地模拟电离室内的等离子体。最后，特别关注推进器性能的分析。