An affordable three dimensional self-consistent multi-fluid model for low temperature plasmas

Summary form only given, as follows. Fully three dimensional multi-fluid plasma models with a set of continuity, momentum and energy equations for each species tend to be prohibitively computationally expensive. Given a clear cut set of assumptions termed the "diffusion approximation", a simplified multi-fluid model is derived that self-consistently describes low temperature plasmas of arbitrary degree of ionisation. It closely resembles traditional fluid equations with additional source terms and two more equations, one for electron temperature and one for either the electric potential or the magnetic field. For example, the model incorporates the non-linear terms in the bulk momentum equation so that it consistently reduces to the Navier-Stokes equation in the limit of vanishing ionisation. Consequently applying time scale arguments derived from the diffusion approximation, most other species related quantities reduce to mere algebraic relations. As a consequence the model is well suited to be incorporated in traditional computational fluid dynamics (CFD) codes because it requires only small extensions of the set of equations to be solved. In particular, this allows plasma modeling in complicated geometries using existing CFD tools with their advanced mesh generators, powerful solvers and post-processing capabilities. Within the framework of a funded research project the model has been implemented in the commercial CFD code FLUENT as one building block to simulate plasma enhanced chemical vapor deposition (PECVD) in industrial scale plasma reactors. Results from ongoing research will be presented.