New model offers 3D insights into plasma-based space propulsion systems
New model offers 3D insights into plasma-based space propulsion systems lead image
Hall Thrusters (HTs) are space propulsion systems that use an E-cross-B discharge to generate thrust by accelerating a plasma. In HTs, classical diffusion cannot explain electron transport and the discrepancy is likely due to the Electron Drift Instability (EDI). Villafana et al. developed a 3D model that improves our understanding of EDIs.
The team’s model, which studies the growth and development of EDIs in 3D, sacrifices speed for accuracy and more realistically captures the physics of EDIs than previous models. For example, other studies perform simulations in 1D or 2D or make simplifying assumptions that cannot depict the inherent 3D nature of EDIs. By comparing their 3D model to an analogous 2D one, the team showed the anomalous transport was probably overestimated in 2D.
“This work is important because it offers a first point of comparison for future 3D Particle-In-Cell (PIC) simulations of HTs and E-cross-B discharges using no scaling factors,” author Willca Villafana said. “Also, the use of unstructured grids is important for the community as industrial partners such as HTs manufacturers use complex geometries that can be difficult to discretize with structured grids.”
The PIC method used by the model’s team allows for capturing kinetic effects, that are numerous in E-cross-B discharges.
“This technique is computationally costly as it requires very small time and space steps to remain stable and accurate,” Villafana said.
Villafana emphasized the need for more advanced PIC algorithms that permit larger time and space steps, as well as efficient use of computational resources, such as GPU acceleration. This requirement is essential for simulating real-world systems within an acceptable timeframe.
Source: “3D particle-in-cell study of the electron drift instability in a Hall Thruster using unstructured grids,” by W. Villafana, B. Cuenot, and O. Vermorel, Physics of Plasmas (2023). The article can be accessed at https://doi.org/10.1063/5.0133963 .
