On the Nystrom Discretization of Integral Equations on Planar Curves with Corners

Abstract

The Nystrom method can produce ill-conditioned systems of linear equations and inaccurate results when applied to integral equations on domains with corners. This defect can already be seen in the simple case of the integral equations arising from the Neumann problem for Laplace's equation. We explain the origin of this instability and show that a straightforward modification to the Nystrom scheme, which renders it mathematically equivalent to Galerkin discretization, corrects the difficulty without incurring the computational penalty associated with Galerkin methods. We also present the results of numerical experiments showing that highly accurate solutions of integral equations on domains with corners can be obtained, irrespective of whether their solutions exhibit bounded or unbounded singularities, assuming that proper discretizations are used.

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Document Details

Document Type
Technical Report
Publication Date
Jul 22, 2010
Accession Number
ADA555144

Entities

People

  • James Bremer

Organizations

  • University of California, Davis

Tags

DTIC Thesaurus Topics

  • Accuracy
  • Boundaries
  • Boundary Value Problems
  • Coordinate Systems
  • Differential Equations
  • Equations
  • Formulas (Mathematics)
  • Helmholtz Equations
  • Integral Equations
  • Integrals
  • Linear Systems
  • Mathematics
  • Numbers
  • Partial Differential Equations
  • Precision
  • Square Roots
  • Three Dimensional

Fields of Study

  • Mathematics

Readers

  • Computational Fluid Dynamics (CFD)
  • Fluid Dynamics.
  • Linear Algebra