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A three-dimensional adaptive multifluid MHD model of the heliosphere

Posted on:1999-06-29Degree:Ph.DType:Dissertation
University:University of MichiganCandidate:Linde, Timur JaanFull Text:PDF
GTID:1460390014470233Subject:Physics
Abstract/Summary:
We present a new self-consistent, two-fluid model of the global heliosphere--a three-dimensional cosmic structure that results from the interaction of the solar wind with the local interstellar medium which surrounds the solar system. The model simulates the interaction of solar and interstellar plasmas in the presence of a background flow of interstellar neutral hydrogen. The plasma medium is described in terms of ideal magnetohydrodynamics, and the hydrogen medium is modeled as a neutral fluid. The two media are weakly coupled via a resonant charge exchange process.;In this work we survey the most recent observational data required for the model development and compose a set of governing equations that mathematically describe the physical behavior of the heliosphere. In order to explain the most fundamental features of the heliosphere we present several simplified analytic solutions of the governing equations. In general, these equations must be solved numerically. We therefore review modern computational fluid- and magnetohydrodynamics methods that can be used for this purpose and propose a simplified solution strategy that takes account of the specific nature of heliospheric problems. In order to validate our numerical algorithm we address accuracy and convergence issues using a set of computed solutions that correspond to known test problems. Finally, we present our heliospheric results. We discuss the overall structure of the global heliosphere, then we concentrate on several specific features that are relevant to space observations. In particular, we outline an interstellar dust study that we have performed using our heliospheric results in order to demonstrate how heliospheric plasma simulations can be utilized for other problems.;We conclude the dissertation by a brief overview of accomplished work and give a set of research directions that we believe will be dominant in future global heliospheric studies.
Keywords/Search Tags:Model, Heliosphere, Global, Heliospheric
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