Natural convection in a square enclosure with four circular cylinders positioned at different rectangular locations
Natural convection in a square enclosure with four circular cylinders positioned at different rectangular locations
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DOI：
10.1016/j.ijheatmasstransfer.2014.10.065
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发表时间：
2015-02
影响因子：
5.2
通讯作者：
Youngju Park;M. Ha;Joung-Man Park
中科院分区：
文献类型：
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作者：
Youngju Park;M. Ha;Joung-Man Park
进行了一项数值研究，以研究由冷的外部方形外壳和放置在矩形阵列中的四个热的内部圆柱体之间的温差引起的自然对流换热。使用精确有效的浸入边界法获得了四个圆柱体外壳中自然对流的二维解。基于有限体积法的浸入边界法用于处理外壳内彼此等距放置的四个内部圆柱体，它们沿着对角中心线移动，对于 103⩽Ra⩽ 106 范围内的不同瑞利数。本研究研究了当圆柱体沿着外壳的对角中心线移动时，外壳中圆柱体的位置对传热和流体流动的影响。对于本研究中考虑的所有情况，流场和热场最终在 103⩽Ra⩽ 104 范围内达到稳定状态。然而，对于 105⩽Ra⩽ 106，流场和热场变得不稳定，具体取决于圆柱体的位置。此外，关于垂直中心线的对称性也受到气缸位置的影响。还给出了瞬时、时间平均局部和表面平均努塞尔数作为瑞利数和内圆柱之间距离的函数的分布。
A numerical study was carried out to investigate natural convection heat transfer induced by a temperature difference between a cold outer square enclosure and four hot inner circular cylinders placed in a rectangular array. A two-dimensional solution for natural convection in an enclosure with four cylinders was obtained using an accurate and efficient immersed boundary method. The immersed boundary method based on the finite volume method was used to handle four inner cylinders placed equal distance away from each other within an enclosure moving along the diagonal centerlines for different Rayleigh numbers in the range 103⩽Ra⩽ 106. This study investigated the effects of the location of the cylinders in the enclosure on the heat transfer and fluid flow, when they moved along the diagonal centerlines of the enclosure. For all the cases considered in the present study, the flow and thermal fields eventually reached steady state in the range of 103⩽Ra⩽ 104. However, for 105⩽Ra⩽ 106, the flow and thermal fields became unsteady depending on the cylinders position. Also, the symmetry about the vertical centerline was affected by the cylinders position as well. The distribution of the instantaneous, time-averaged local and surface-averaged Nusselt number as a function of the Rayleigh number and the distance between inner cylinders was also presented.