Boundary Conditions at the Walls with Thermionic Electron Emission in Two Temperature Modeling of "Thermal" Plasmas

TL;DR

This paper introduces new boundary conditions for hot walls with thermionic electron emission in two-temperature thermal plasma models, enabling more accurate self-consistent calculations of heat flux and electron currents.

Contribution

It develops boundary conditions considering thermionic emission and sheath effects, improving the modeling of plasma-wall interactions in thermal arc simulations.

Findings

Boundary conditions incorporate thermionic electron emission effects.

The model achieves self-consistent calculation of heat flux and electron current.

Applicable to refractory metal walls with minimal erosion.

Abstract

In this paper we propose new boundary conditions at the hot walls with thermionic electron emission for two-temperature thermal arc models. In the derived boundary conditions the walls are assumed to be made from refractory metals and that the erosion of the wall is small and, therefore, is not taken into account in the model. In these boundary conditions the plasma sheath formed at the electrode is considered as the interface between the plasma and the wall. The derived boundary conditions allow the calculation of the heat flux to the walls from the plasma and consequently the thermionic electron current that makes the two temperature thermal model self consistent.