A Least-Squares approach to Two-Fluid, Electromagnetic Plasma

Date
4/19/2019
Location
11:30AM at REC 307
Speaker
Prof. Tom Manteuffel, University of Colorado Boulder
Title
A Least-Squares approach to Two-Fluid, Electromagnetic Plasma
Host
Guang Lin
Description

A two-fluid plasma (TFP) model is presented, both as a stand-alone solver and as the preconditioner to a fully implicit, particle-in-cell (PIC) simulation. The model couples fluid conservation equations for ions and electrons to Maxwells equations. A Darwin approximation of Maxwell is used to eliminate spurious light waves. After scaling and modification, the TFP-Darwin model yields a nonlinear, first-order system of equations whose Frechet derivative is shown to be uniformly H1-elliptic. This system is addressed numerically by nested iteration (NI), a First-Order System Least Squares (FOSLS) discretization, adaptive local mesh refinement, and scaled AMG system solver. Numerical tests demonstrate the efficacy of this approach, yielding an approximate solution within discretization error in a relatively small number of computational work units.

Time permitting, a discussion of Vlasov-Maxwell equations will be will be started. A numerical approach will be presented that includes the possibility of using the TFP model as a preconditioning.