Multi-fluid, high-order moment models for partially ionized plasmas
Kentaro Hara
Stanford University
Aeronautics and Astronautics
Plasma physics and chemistry play an important role in controlling and designing plasma sources for various applications. While kinetic models are considered high fidelity due to their ability to resolve non-Maxwellian velocity distribution functions of charged particles, the computational cost is often prohibitive for large-scale simulations. Fluid (hydrodynamic) models are often computationally cheaper and lower fidelity as the transport equations of macroscopic properties are solved instead of first-principles kinetic equations. These fluid models can be derived by taking the moments of the kinetic equations, such as the Boltzmann equation, from which closure models of the fluid equations can be constructed. In this talk, I will introduce the development of 5-moment (mass, momenta, and mean energy), 10-moment (mass, momenta, and anisotropic pressure), and 14-moment (mass, momenta, anisotropic pressure, contracted heat flux, and contracted kurtosis) for partially ionized plasmas that include plasma-wall interactions and volumetric reactions, including electron-neutral, electron-electron, and electron-ion collisions. These multi-moment models are compared with kinetic simulations to assess their fidelity for low-pressure DC and RF plasmas.