Numerical Experiments with Flows of Elongated Granules

Abstract

Theory and numerical results are given for a program simulating two- dimensional granular flows (1) between two infinite, counter-moving, parallel, roughened walls, and (2) for an infinitely-wide slider. Each granule is simulated by a central repulsive force field ratcheted with force restitution factor to introduce dissipation. Transmission of angular momentum between particles occurs via Coulomb friction. The effect of granule hardness is explored. Gaps from 7 to 28 particle diameters are investigated, with solid fractions ranging from 0.2 to 0.9. Among features observed are: slip flow at boundaries, coagulation at high densities, and gross fluctuations in surface stress. A videotape has been prepared to demonstrate the foregoing effects.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1992
Accession Number
ADA251853

Entities

People

  • David E. Brewe
  • Harold G. Elrod

Organizations

  • National Aeronautics and Space Administration

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Angular Momentum
  • Boundaries
  • Computational Fluid Dynamics
  • Computer Simulations
  • Diameters
  • Energy
  • Equations
  • Equations Of Motion
  • Flow Visualization
  • Friction
  • Geometry
  • Granular Materials
  • Hardness
  • High Density
  • Numerical Analysis
  • Shear Flow
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Aerosol Science/Aerosol Physics
  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Tribology (the study of the boundary interaction between sliding surfaces, lubrication, wear and friction).