Development of a Multifluid Magnetohydrodynamic Model for Anisotropic, Partially Ionized Plasmas

A multifluid magnetohydrodynamic (MHD) model based on an extended fluid dynamics description for each plasma species is proposed for the prediction of the flow and behaviour of fully and partially ionized non-equilibrium anisotropic plasmas. Two-(electrons and ions) and three-fluid (ions, electrons and neutrals) plasma models are described that both make use of a 10-moment or Gaussian anisotropic moment closure of the Boltzmann equation. The moment equations for each plasma species are fully coupled to the Maxwell's equations which govern electromagnetic wave propagation within the plasma and a Bhatnagar-Gross-Krook (BGK) relaxation time approximation is used to model non-equilibrium collisional processes between the plasma species. Chemical kinetic models are included to represent the partially ionized plasma processes. Unlike conventional MHD models, the proposed multi-species MHD model is capable of taking into account large temperature anisotropies and temperature differences between the electrons and ions, both of which can occur for low-density, high-temperature plasmas and/or strongly magnetized plasmas. A second-order Godunov-type finite-volume method is developed for the solution of the one- and two-dimensional forms of the multifluid plasma models, which includes temporal limiting in one-dimension and a parallel scheme utilizing a Newton-Krylov-Schwarz (NKS) implicit algorithm for the two-dimensional solution procedure. The numerical fluxes in the Godunov-type scheme are solved using HLLE and Godunov numerical flux functions. The two-dimensional solution procedure includes Generalized Lagrange Multiplier (GLM) and diffusive error correction schemes for the treatment of divergence errors associated with the electromagnetic field. An accuracy assessment is performed for the two-dimensional numerical solution procedure, demonstrating good convergence of solutions for a range of problems. The validated two-dimensional solution procedure for the multifluid MHD model is then applied to the solution of the well-known Geospace Environmental Modelling (GEM) challenge problem involving magnetic field reconnection and numerical results are compared to established solutions in the literature. Results of grid refinement and parametric studies for the GEM case are also described. The proposed multifluid MHD model is shown to recover known published results with relatively small computational effort and the potential of the proposed treatment for describing a range of non-equilibrium anisotropic plasma flows is demonstrated.

Department dc:contributor.department

Aerospace Science and Engineering

Year dc:date.issued

2019

Author dc:creator

• Miura, Ken

Advisor dc:contributor.advisor

• Groth, Clinton P. T.

• computational fluid dynamics
• geospace magnetic reconnection
• magnetohydrodynamics
• MHD
• plasmadynamics
• plasma modelling

Handle dc:identifier.uri

http://hdl.handle.net/1807/95918

OAI identifier oai:identifier

oai:utoronto.scholaris.ca:1807/95918