Exploiting Partial Symmetry in Vortex Lattice Models

Abstract

Symmetry is commonly used to cut computation time; however, it is usually an all-or-nothing proposition. This need not be the case for vortex lattice computations. As an example, consider an airplane, symmetric with respect to a vertical plane through its nose and tail. If the free stream is parallel to the plane of symmetry, then numerical computations can be applied to half the airplane, and symmetry can be assumed for the other half. If, however, the free stream is not parallel to the plane of symmetry and/or if an instrument pod is added under one wing, then symmetry is spoiled. In vortex lattice computations, the symmetry of the airplane can still be used to advantage, not only in computation of the coefficients of the linear algebraic system, but more so in its solution. Computation time for a completely symmetric system is reduced, in comparison to that for an asymmetric system of the same size, by a factor of eight for one plane of symmetry. If there are two or three planes of symmetry, the factors are 64 and 512, respectively. If the system is only partially symmetric , the corresponding factors may still be as high as 4, 16, and 64.

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Document Details

Document Type
Technical Report
Publication Date
Jul 01, 1981
Accession Number
ADA102573

Entities

People

  • Bharat K. Soni
  • Donald C. Todd

Organizations

  • Arnold Engineering Development Complex

Tags

DTIC Thesaurus Topics

  • Aerodynamic Characteristics
  • Air Force
  • Aircrafts
  • Airplanes
  • Computations
  • Computer Programs
  • Computers
  • Engineering
  • Flow
  • Fluid Dynamics
  • Free Stream
  • Government Procurement
  • Governments
  • Mathematical Analysis
  • Technical Information Centers
  • Theorems
  • United States

Fields of Study

  • Mathematics

Readers

  • Aerodynamics/Aeronautics.
  • Fluid Dynamics.
  • Systems Analysis and Design