Derivation of a Generalized Von Neumann Pseudo-Viscosity with Directional Properties

Abstract

An absolute scalar pseudo-viscosity ("q") expression for handling shocks automatically in numerical calculations of three-dimensional fluid dynamics problems is derived. The expression is a generalization of that derived by von Neumann and Richtmyer in the sense that the expressions are identical for a plane shock wave. The basic assumption made is that a shock will be formed in a material when there is compression in the direction of acceleration; this assumption seems "reasonable" physically, since this condition indicates that a grid established about a point with such compression will collapse, i.e. the "rear" of the grid will overtake the "front". The expression "q" is derived for a generalized curvilinear coordinate space and the expression is given for the three commonly used coordinate systems. The expression is also written for the plane rectangular case and the cylindrical case with no angular motion to be used in connection with the HEMP code.

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Document Details

Document Type
Technical Report
Publication Date
Jul 21, 1965
Accession Number
ADA382523

Entities

People

  • Gerald T. Richards

Organizations

  • University of California

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Angular Motion
  • California
  • Cartesian Coordinates
  • Contractors
  • Contracts
  • Coordinate Systems
  • Directional
  • Equations Of Motion
  • Fluid Dynamics
  • Geometry
  • Grids
  • Materials
  • Mathematics
  • Radiation
  • Two Dimensional
  • United States
  • Universities

Fields of Study

  • Physics

Readers

  • Combustion Dynamics and Shock Wave Physics.
  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)

Technology Areas

  • Space