Fast Solvers and Uncertainty Quantification for Models of Magnetohydrodynamics

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dc.contributor.advisorElman, Howard Cen_US
dc.contributor.authorPhillips, Edward Geoffreyen_US
dc.contributor.departmentApplied Mathematics and Scientific Computationen_US
dc.contributor.publisherDigital Repository at the University of Marylanden_US
dc.contributor.publisherUniversity of Maryland (College Park, Md.)en_US
dc.date.accessioned2014-10-11T05:46:17Z
dc.date.available2014-10-11T05:46:17Z
dc.date.issued2014en_US
dc.description.abstractThe magnetohydrodynamics (MHD) model describes the flow of electrically conducting fluids in the presence of magnetic fields. A principal application of MHD is the modeling of plasma physics, ranging from plasma confinement for thermonuclear fusion to astrophysical plasma dynamics. MHD is also used to model the flow of liquid metals, for instance in magnetic pumps, liquid metal blankets in fusion reactor concepts, and aluminum electrolysis. The model consists of a non-self-adjoint, nonlinear system of partial differential equations (PDEs) that couple the Navier-Stokes equations for fluid flow to a reduced set of Maxwell's equations for electromagnetics. In this dissertation, we consider computational issues arising for the MHD equations. We focus on developing fast computational algorithms for solving the algebraic systems that arise from finite element discretizations of the fully coupled MHD equations. Emphasis is on solvers for the linear systems arising from algorithms such as Newton's method or Picard iteration, with a main goal of developing preconditioners for use with iterative methods for the linearized systems. In particular, we first consider the linear systems arising from an exact penalty finite element formulation of the MHD equations. We then draw on this research to develop solvers for a formulation that includes a Lagrange multiplier within Maxwell's equations. We also consider a simplification of the MHD model: in the MHD kinematics model, the equations are reduced by assuming that the flow behavior of the system is known. In this simpler setting, we allow for epistemic uncertainty to be present. By mathematically modeling this uncertainty with random variables, we investigate its implications on the physical model.en_US
dc.identifierhttps://doi.org/10.13016/M2DG6G
dc.identifier.urihttp://hdl.handle.net/1903/15753
dc.language.isoenen_US
dc.subject.pqcontrolledApplied mathematicsen_US
dc.subject.pquncontrolledIterative Methodsen_US
dc.subject.pquncontrolledMagnetohydrodynamicsen_US
dc.subject.pquncontrolledPreconditionersen_US
dc.subject.pquncontrolledUncertainty Quantificationen_US
dc.titleFast Solvers and Uncertainty Quantification for Models of Magnetohydrodynamicsen_US
dc.typeDissertationen_US

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