Natural convection in a mushy layer
1991; Cambridge University Press; Volume: 224; Linguagem: Inglês
10.1017/s0022112091001787
ISSN1469-7645
Autores Tópico(s)Heat and Mass Transfer in Porous Media
ResumoGoverning equations for a mushy layer are analysed in the asymptotic regime R m [Gt ] 1, where R m is an appropriately defined Rayleigh number. A model is proposed in which there is downward flow everywhere in the mushy layer except in and near localized chimneys, which are characterized by having zero solid fraction. Upward, convective flow within the chimneys is driven by compositional buoyancy. The radius of each chimney is determined locally by thermal balances within a boundary layer that surrounds it. Simple solutions are derived to determine the structure of the mushy layer away from the immediate vicinity of chimneys in order to demonstrate the gross effects of convection upon the solidification within the layer.
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