University of Illinois Urbana-Champaign

Traveling waves standing waves and cellular patterns in steadily forced granular medium

Fried, Eliot; Shen, Amy Q.; Thoroddsen, Sigurdur T.

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https://hdl.handle.net/2142/112555

Description

Title
Traveling waves standing waves and cellular patterns in steadily forced granular medium
Author(s)
  • Fried, Eliot
  • Shen, Amy Q.
  • Thoroddsen, Sigurdur T.
Issue Date
1997-04
Keyword(s)
  • Cellular Pattern
  • Granular Medium
Abstract
Wave-patterns and cellular structures often appear in periodically excited granular media . We show that, even under steady forcing, traveling and standing waves can form in a thin layer of sand inside a rotating cylinder. The cylinder is rotated about its horizontal axis of symmetry at constant angular velocity. A competition between gravitation, intergranular frictional force , and grain inertia induces a spanwise instability characterized by serrated frontal shapes remarkably similar to those observed in Newtonian fluids. Within a certain parameter range, an accompanying spatial pattern forms on the rising side of the cylinder and travels along the cylinder span. The associated phase velocity is relatively constant, whereas the relevant wavelength increases linearly with angular rotation speed. Standing waves appear at a critical rotation rate. Further, in some cases, a propagating cellular pattern forms on the surface of the medium.
Publisher
Department of Theoretical and Applied Mechanics. College of Engineering. University of Illinois at Urbana-Champaign
Series/Report Name or Number
  • TAM R 852
  • 1997-6013
ISSN
0073-5264
Type of Resource
text
Language
eng
Permalink
http://hdl.handle.net/2142/112555
Copyright and License Information
Copyright 1997 Board of Trustees of the University of Illinois

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Technical Reports - Theoretical and Applied Mechanics (TAM) PRIMARY
TAM technical reports include manuscripts intended for publication, theses judged to have general interest, notes prepared for short courses, symposia compiled from outstanding undergraduate projects, and reports prepared for research-sponsoring agencies.