Feasibility and Comparison Investigation of the Use of the Fast Fourier Transform and Finite Difference Method for Numerical Solution of Boundary Value Problems.

Abstract

This thesis determined the feasibility of using Fast Fourier Transforms (FFT) to solve Boundary Value Problems (BVP) and then compare the results to those of the Finite Difference Method (FDM). Variations of Poisson's one and two dimensional equations were used as a vehicle to develop the FFT method. For the one dimensional BVP, both homogeneous and non-homogeneous Dirichlet boundary conditions were considered. In the one dimensional BVP the inhomogeneous function, F(x), was also varied. The two dimensional BVP, only one inhomogeneous function, F(x,y), and homogeneous boundary conditions were used. The one dimensional model was used as a basis for developing the two dimensional model. The analytical solution of each problem was compared to the numerical solution of the FDM and the FFt method at varying mesh sizes. The computational time of the FDM and the FFT method were also compared. The results indicate that the FFT is extremely efficient in the two dimensional BVP because of the computer storage space required and the computational time needed to solve the FFTs. The accuracy of the FFT compares favorably to the FDM and, as the mesh size decreases, becomes more accurate than the FDM.

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1986
Accession Number
ADA172719

Entities

People

  • Todd R. Jones

Organizations

  • Air Force Institute of Technology

Tags

Communities of Interest

  • Materials and Manufacturing Processes
  • Weapons Technologies

DTIC Thesaurus Topics

  • Accuracy
  • Air Force
  • Artillery
  • Boundaries
  • Boundary Value Problems
  • Classification
  • Computer Programs
  • Computers
  • Differential Equations
  • Discrete Fourier Transforms
  • Equations
  • Fast Fourier Transforms
  • Fourier Transformation
  • Poisson Equation
  • Simultaneous Equations
  • Two Dimensional
  • United States Military Academy

Readers

  • Approximation Theory.
  • Calculus or Mathematical Analysis
  • Computational Fluid Dynamics (CFD)

Technology Areas

  • Space