Numerical Investigation of Electron Energy Transport in Hall Thrusters

Le résumé fourni par la source

Self-consistent closures for the electron heat flux and collision frequency in a multi-fluid Hall thruster model are parametrically investigated. A form of the anomalous collision frequency that follows the scaling of the classical electron-ion collision frequency is employed. Three separate models of a free-stream heat flux along magnetic field lines are explored and compared to a classical Spitzer-Harm representation. These models are applied to a 9-kW class Hall thruster operating on xenon and krypton and compared to experimental measurements of internal plasma properties and global thruster performance. It is found that with the modified heat flux, the model is self-consistently able to capture ion velocity measurements as well as the 2D electron temperature along magnetic field lines. However, the model underpredicts peak temperature along centerline by 25% and performance metics by 35%. These results are discussed in the context of the physical significance of the freestream heat flux. The extensibility of the model is explored and shown to be able to represent changes in the ion velocity across propellant, discharge voltage, and discharge current by only adjusting a single scaling constant.

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