Natural convection in a mushy layer
Natural convection in a mushy layer
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DOI：
10.1017/s0022112091001787
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发表时间：
1991-03
影响因子：
3.7
通讯作者：
M. Worster
中科院分区：
文献类型：
--
作者：
M. Worster
在渐近区域Rm [Gt] 1中分析了糊状层的控制方程，其中Rm是一个适当定义的瑞利数。提出了一种除局部烟囱内和烟囱附近均为向下流动的模型，其特征是固体分数为零。向上，烟囱内的对流流动是由组成浮力驱动的。每个烟囱的半径是由围绕它的边界层内的热平衡局部决定的。为了证明对流对层内凝固的总体影响，导出了简单的解来确定远离烟囱附近的糊状层的结构。
Governing equations for a mushy layer are analysed in the asymptotic regime Rm [Gt ] 1, where Rm 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.