University of Illinois Urbana-Champaign

Buoyancy driven flow in rotating low prandtl number melt during alloy solidificastion

Riahi, Daniel N.

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https://hdl.handle.net/2142/112622

Description

Title
Buoyancy driven flow in rotating low prandtl number melt during alloy solidificastion
Author(s)
Riahi, Daniel N.
Issue Date
1999-07
Keyword(s)
  • Buoyancy Driven Flow
  • Prandtl Number
  • Alloy Solidificastion
Abstract
Buoyancy driven chimney convection in low Prandtl number melts within a mushy layer during alloy solidification is reviewed under external constraint of rotation, where the rotation axis is inclined at an angle ϒ to the direction of the solidification velocity. The chimneys within the mushy layer produce undesirable freckles in the final form of the crystal, which are imperfections that reduce the quality of the crystal. Methods of control aiming at eliminating or reducing significantly the convective flows in the chimneys also serve to eliminate or reduce significantly the existence and presence of the chimneys in the mushy layer which can result in producing higher quality crystals. Asymptotic and scaling examinations of the governing system for the non-axisymmetric chimney convection have resulted in discoveries of ranges in ϒ, Prandtl number, Coriolis parameter and centrifugal parameter where chimney convection can be reduced significantly. These results also confirm the experimental observation in low Prandtl number melts that the Coriolis effect can have a stabilizing or destabilizing influence depending on the rotation sense of the solidification system.
Publisher
Department of Theoretical and Applied Mechanics. College of Engineering. University of Illinois at Urbana-Champaign
Series/Report Name or Number
  • TAM R 914
  • 1999-6016
ISSN
0073-5264
Type of Resource
text
Language
eng
Permalink
http://hdl.handle.net/2142/112622
Copyright and License Information
Copyright 1999 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.