Brash Ice Behavior.

Abstract

The behavior of brash ice, its formation and recommended vessel operating procedures are presented. Brash ice behaves as a Mohr-Coulomb solid below a critical strain rate or ship speed. Above this speed, fluidization of the medium occurs and the resistance appears to be that of a viscous, laminar fluid. The optimum operating speed for a vessel in brash is at the viscous threshold, found here to be 0.12 sg.rt of gL) where g (32.2 fS-2) is the acceleration of gravity and L is the length of the vessel. Repeated passages through brash-filled channels to keep them unconsolidated are generally unadvisable due to the attendant enhancement of the accretion rates. The laboratory and field experiments employed in this study are presented. Laboratory tests in brash ice appear to yield very useful results that are good predictors of full-scale resistance. (Author)

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Document Details

Document Type
Technical Report
Publication Date
May 01, 1981
Accession Number
ADA104152

Entities

People

  • Paul Greisman

Organizations

  • United States Coast Guard Research & Development Center

Tags

Communities of Interest

  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Air Temperature
  • Chemistry
  • Coast Guard
  • Cold Regions
  • Elastic Properties
  • Engineering
  • Field Tests
  • Flow
  • Fluids
  • Fresh Water
  • Friction
  • Glaciers
  • Laminar Flow
  • Materials
  • Open Water
  • Strain Rate
  • Temperature Gradients

Readers

  • Geotechnical Engineering.
  • Military Engineering.
  • Plasma Physics / Magnetohydrodynamics