A system of mass balance equations is set up for plasma-chemical simulations, we derive the diffusion velocities from Stefan-Maxwell theory. An algorithm to linearly transform the system of mass balance equations in the context of non-LTE plasmas is described. This transformation is derived from the reaction set, and eliminates part of the chemical source term, enforces invariants such as conservation of mass and quasi-neutrality up to machine precision, provides a reduction in the number of unknowns, and significantly improves conditioning of the discretized system. The MATLAB code used in the numerical experiments is available on GitLab: https://gitlab.com/ChrisSchoutrop/stoichiometric-transformation.
- Conservation of invariants
- Multicomponent transport
- Partial elimination chemical sources
- Plasma physics
- Regularization of diffusion matrix
- Stoichiometric transformation