Numerical Generation of Composite Three Dimensional Grids by Quasilinear Elliptic Systems,

Abstract

A technique is presented for constructing a boundary-conforming grid throughout a general three-dimensional flow region as a composite of subregion grids. Each subregion grid is generated numerically by solving quasilinear system of elliptic equations. The boundary values represents nodal points in a quasi-two-dimensional grid that covers the curved surface bounding the subregion, and are generated numerically by a modified elliptic system. The boundary values are used to computer grid control parameters that are contained in the elliptic systems. This provides flexible control over the distribution of grid points in the interior of the region, in that the interior grid distribution is governed by the distribution of points on the boundary as well as by boundary's geometric shape. A primary feature of the technique is that the composite three-dimensional grid remains both continuous and smooth across the surface of juncture between any two adjoining subregions. The present paper elucidates the details of the method and of its implementation, and displays numerical results for both surface grids and space grids. Comprehensive results are displayed for a three-dimensional grid about a simple wing-body combination. A numerical example is presented of a surface grid on a NACA 0012 airfoil, with high resolution of the wingtip region. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1982
Accession Number
ADP000996

Entities

People

  • P. D. Thomas

Organizations

  • Lockheed Martin Missiles and Space

Tags

DTIC Thesaurus Topics

  • Boundaries
  • Composite Materials
  • Coordinate Systems
  • Demographic Cohorts
  • Differential Equations
  • Equations
  • Grids
  • High Resolution
  • Partial Differential Equations
  • Three Dimensional
  • Three Dimensional Flow
  • Two Dimensional

Fields of Study

  • Mathematics
  • Physics

Readers

  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)
  • Fluid Mechanics and Fluid Dynamics.

Technology Areas

  • Space