Full Newton AMR solver with fast-slow model split and implicit multi-temperature chemistry*

We present a multi-fluid, multi-temperature plasma solver with adaptive Cartesian mesh based on a full-Newton (non-linear, implicit) scheme for collisional low-temperature plasma. The implicit treatment of the coupled equations allows using large time steps, and the full-Newton method enables fast non-linear convergence at each time step, offering improved efficiency of fluid plasma simulations on dynamically adaptive grids [1]. We have enhanced our solver using a modular split of the fast (electron) and slow (ion) transport solvers to address the disparity of the electron and ion time scales. Significant speedup has been obtained, which scales well with increasing the number of ion species and becomes vital as the number of species grows in complex gas mixtures. The fast-slow split also facilitates using kinetic solvers for electrons to our hybrid framework. We have further enhanced our plasma solver with an implicit chemistry module enabling multi-temperature reaction rates for electron-induced reactions and reactions among heavy species. The implementation of the full-Newton method (FNM) with adaptive mesh refinement (AMR) utilizes state-of-the-art numerical CFD algorithms. The new solver enables solving challenging problems in a numerically efficient manner to study plasma self-organization in gas discharges and pattern formation during plasma-surface interactions.

 

[1] R.R. Arslanbekov and V.I. Kolobov, Implicit and coupled fluid plasma solver with adaptive Cartesian mesh and its applications to non-equilibrium gas discharges, Plasma Sources Sci. Technol. 30 (2021) 045013