University of Illinois Urbana-Champaign

Stationary and oscillatory modes of flow instabilities in a rotating porous layer during alloy solidification

Riahi, Daniel N.

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https://hdl.handle.net/2142/112682

Description

Title
Stationary and oscillatory modes of flow instabilities in a rotating porous layer during alloy solidification
Author(s)
Riahi, Daniel N.
Issue Date
2001-11
Keyword(s)
  • Alloy Solidification
  • Flow Instabilities
  • Rotating Porous Layers
Abstract
Linear flow instabilities due to either stationary or oscillatory mode of disturbances in a horizontal porous layer during alloy solidification are investigated under an external constraint of rotation. The porous layer, which is referred to as a mushy layer in the solidification literature, is assumed to rotate about the vertical axis at a constant angular velocity. The investigation is based on the model of Amberg and Homsy (1993) and under the limit of large Stefan number as treated by Anderson and Worster (1996) in the absence of the rotational constraint. Over an extensive range of the parameter values, the oscillatory mode is found to correspond to smaller critical value Re of the Rayleigh number at the onset of motion as compared to the corresponding one for the stationary mode. Results of the stability analyses indicate both stabilizing and destabilizing effects of the Coriolis force on the flow in the porous layer. For example, the effects of the Coriolis force can be stabilizing in the sense that Re increases with the rotation rate, while the effects of the Coriolis force can be destabilizing in the sense that the oscillatory instability is enhanced in the presence of rotation.
Publisher
Department of Theoretical and Applied Mechanics. College of Engineering. University of Illinois at Urbana-Champaign
Series/Report Name or Number
  • TAM R 989
  • 2001-6028
ISSN
0073-5264
Type of Resource
text
Language
eng
Permalink
http://hdl.handle.net/2142/112682
Copyright and License Information
Copyright 2001 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.