University of Illinois Urbana-Champaign

Magnetohydrodynamic effects in high gravity convection during alloy solidification

Riahi, Daniel N.

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https://hdl.handle.net/2142/112655

Description

Title
Magnetohydrodynamic effects in high gravity convection during alloy solidification
Author(s)
Riahi, Daniel N.
Issue Date
2000-06
Keyword(s)
  • Magnetohydrodynamic Effects
  • Alloy Solidification
Abstract
Nonlinear compositional convection in the melt and in cylindrical chimneys within a mushy layer during solidification of a binary alloy is investigated subjected to a strong magnetic field and under high gravity environment. These chimneys produce freckles in the final form of the solidified material, which are imperfections that reduce the quality of the solidified material. Asymptotic and scaling analyses are applied to axisymmetric convection in the melt and in the chimneys. Three important nondimensional parameters in this study are the solutal Rayleigh number R, the centrifugal acceleration parameter A and the Chandrasekhar number (magnetic parameter) Q. It is found that magnetohydrodynamic effects, due to the presence of a strong magnetic field, are stabilizing in the sense that convection and freckle formation can be reduced significantly. Such stabilizing effects can be enhanced by the presence of a moderate rate of rotation due to the centrifugal force effects of the high gravity environment. In this stabilizing regime chimney convection decreases with increasing either A or Q, even though it still increases with R.
Publisher
Department of Theoretical and Applied Mechanics. College of Engineering. University of Illinois at Urbana-Champaign
Series/Report Name or Number
  • TAM R 945
  • 2000-6020
ISSN
0073-5264
Type of Resource
text
Language
eng
Permalink
http://hdl.handle.net/2142/112655
Copyright and License Information
Copyright 2000 Board of Trustees of the University of Illinois

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