Using commercial, academic, and open-source software for low temperature plasmas: Fluid and Hybrid methods*

We present a broad overview of commercial, academic, and open-source software for low temperature plasmas focusing on fluid and hybrid methods. Key features of of CFD-ACE [1], COMSOL [2], VizGlow [3], Usim [4], gerris/basilisk [5], and openFOAM [6] are evaluated and compared with respect to physical models and numerical techniques. The most important differences between these computational tools consist of different methods of mesh generations and discretization of PDEs describing plasma. The first class of tools uses body-fitted structured and unstructured static mesh, which can be highly non-uniform to account for large gradients of plasma parameters in the narrow space-charge sheaths. The second class uses non-surface-aligned mesh, which can be automatically generated around embedded objects and can be dynamically adapted to solution properties and moving boundaries. The second difference between the tools consist of discretizing PDEs using FV and FE methods. The third difference is how the sets of the equation are solved: in a coupled way or sequentially. In terms of physics, fluid models are typically used for ions and neutrals whereas electrons can be described by either a fluid model, by solving grid-based kinetic equations, or using particle-based methods. An external circuit simulator is often needed, which controls the time step in coupled plasma-circuit computations. When the time-stepping schemes are implicit, a nonlinear system of equations must be solved each time step (e.g., Newton solver). We will illustrate the benefits and drawbacks of different software packages on selected gas discharge problems and discuss current challenges and potential future developments.

[1] https://www.esi.com.au/software/cfd-ace

[2] https://www.comsol.com/

[3] https://esgeetech.com/products/vizglow-plasma-modeling/

[4] https://txcorp.com/usim/

[5] 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

[6] A. K. Verma and A. Venkattraman, SOMAFOAM: An OpenFOAM based solver for continuum simulations of low-temperature plasmas, Comp. Phys. Comm. 263 (2021) 107855