Authors

Tongfei Guo

Type

Text

Type

Dissertation

Advisor

Samulyak, Roman | Glimm, James | Jiao, Xiangmin | Calder, Alan.

Date

2013-12-01

Keywords

Mathematics | embedded boundary method, front tracking, Lagrangian particle method, magnetohydrodynamics

Department

Department of Applied Mathematics and Statistics.

Language

en_US

Source

This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree.

Identifier

http://hdl.handle.net/11401/77643

Publisher

The Graduate School, Stony Brook University: Stony Brook, NY.

Format

application/pdf

Abstract

New mesh and meshless algorithms for elliptic boundary and elliptic interface problems have been developed. By utilizing the embedded boundary method, a mesh based algorithm to solve elliptic interface problem is implemented as an extension of hybrid Eulerian-Lagrangian hydrodynamic library FronTier which employs the method of front tracking for interface propagation and this implementation is parallelized for distributed memory clusters. The use of embedded boundary method supports arbitrary discontinuities of density and other physics properties across the interfaces and significantly improves methods that smear interface discontinuities across several grid cells. This code has been applied to process simulation for heat transfer problem, stefan problem and magnetohydrodynamics at low magnetic Reynolds number. To handle problems brought by the complexity of interfaces, algorithms for solving elliptic boundary and elliptic interface problems have been proposed based on meshless particle-based method. The typical feature of the elliptic interface problem is the presence of a geometrically complex internal boundary across which material properties or solutions rapidly change. The main motivation for the development of particle-based methods for elliptic problems is to carry out numerical simulation of free surface of multiphase systems described by coupled hyperbolic and elliptic equations. A Lagrangian particle technique, smoothed particle hydrodynamics(SPH) has been implemented and tested. To overcome the drawbacks of poor numerical accuracy of SPH, another Lagrangian particle technique with local polynomial fitting has been developed and implemented. All the implementation is fully parallelized. The current work deals with methods for elliptic components of coupled systems. And, the developed elliptic methods, if used independently, also favorably compare to unstructured finite element methods that require mesh generation and depend on the mesh quality. Currently, a second order accurate algorithm has been used and higher order discretization is also possible. | 112 pages

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.