Title page for ETD etd-02152010-150350


Type of Document Master's Thesis
Author Kurzen, Matthew James
Author's Email Address kurzen@vt.edu
URN etd-02152010-150350
Title Discretization Error Estimation and Exact Solution Generation Using the 2D Method of Nearby Problems
Degree Master of Science
Department Aerospace and Ocean Engineering
Advisory Committee
Advisor Name Title
Roy, Christopher J. Committee Chair
McCue-Weil, Leigh S. Committee Member
Tafti, Danesh K. Committee Member
Keywords
  • Discretization Error
  • Method of Manufactured Solutions
  • Computational Fluid Dynamics
  • Method of Nearby Problems
  • MNP
Date of Defense 2010-02-01
Availability unrestricted
Abstract
This work examines the Method of Nearby Problems as a way to generate analytical exact solutions to problems governed by partial differential equations (PDEs). The method involves generating a numerical solution to the original problem of interest, curve fitting the solution, and generating source terms by operating the governing PDEs upon the curve fit. Adding these source terms to the right-hand-side of the governing PDEs defines the nearby problem.

In addition to its use for generating exact solutions the MNP can be extended for use as an error estimator. The nearby problem can be solved numerically on the same grid as the original problem. The nearby problem discretization error is calculated as the difference between its numerical solution and exact solution (curve fit). This is an estimate of the discretization error in the original problem of interest.

The accuracy of the curve fits is quite important to this work. A method of curve fitting that takes local least squares fits and combines them together with weighting functions is used. This results in a piecewise fit with continuity at interface boundaries. A one-dimensional Burgers’ equation case shows this to be a better approach then global curve fits.

Six two-dimensional cases are investigated including solutions to the time-varying Burgers’ equation and to the 2D steady Euler equations. The results show that the Method of Nearby Problems can be used to create realistic, analytical exact solutions to problems governed by PDEs. The resulting discretization error estimates are also shown to be reasonable for several cases examined.

Files
  Filename       Size       Approximate Download Time (Hours:Minutes:Seconds) 
 
 28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access 
  Kurzen_MJ_T_2010.pdf 37.54 Mb 02:53:47 01:29:22 01:18:12 00:39:06 00:03:20
  Kurzen_MJ_T_2010_Copyright.pdf 368.52 Kb 00:01:42 00:00:52 00:00:46 00:00:23 00:00:01

Browse All Available ETDs by ( Author | Department )

dla home
etds imagebase journals news ereserve special collections
virgnia tech home contact dla university libraries

If you have questions or technical problems, please Contact DLA.