The natural convection in a square enclosure with two hot inner cylinders, Part I: The effect of one elliptical cylinder with various aspect ratios in a vertical array
The natural convection in a square enclosure with two hot inner cylinders, Part I: The effect of one elliptical cylinder with various aspect ratios in a vertical array
复制标题
DOI：
10.1016/j.ijheatmasstransfer.2018.04.141
复制
发表时间：
2018-10
影响因子：
5.2
通讯作者：
H. Cho;Y. Park;M. Ha
中科院分区：
文献类型：
--
作者：
H. Cho;Y. Park;M. Ha
本文数值研究了瑞利数Ra≤ 106时，正方形封闭空间中圆柱和椭圆柱垂直排列的二维自然对流换热。为了得到精确解，采用浸入边界法进行了数值模拟。在0.25 ≤AR≤ 4.00的范围内，研究了椭圆柱的长径比对椭圆柱振动特性的影响。当Rayleigh数增加到Ra = 106时，除AR = 2.00和AR = 4.00外，下椭圆柱和上椭圆柱的所有情况的数值解都达到非定常状态。流态从非定常状态到定常状态的转变取决于椭圆柱比的变化。此外，在上椭圆柱atAR= 0.50的情况下，时间和表面平均的Nusselt数的外壳的壁增加了2.1%的情况下，两个圆柱atRa= 106。
This study numerically investigates the two-dimensional natural convection in a square enclosure with a vertical array of one circular cylinder and one elliptical cylinder at Rayleigh numbers of 104≤Ra≤ 106. A simulation was carried out based on the immersed boundary method to obtain an accurate solution. The effects of the aspect ratio of the elliptical cylinder in the range of 0.25 ≤AR≤ 4.00 were investigated. When the Rayleigh number increases toRa= 106, the numerical solutions reach an unsteady state for all cases of the lower elliptical cylinder and the case of the upper elliptical cylinder except atAR= 2.00 andAR= 4.00. The transition of the flow regime from the unsteady state to the steady state depends on the variation in the ratio of the elliptical cylinder. In addition, in the case of the upper elliptical cylinder atAR= 0.50 the time- and surface-averaged Nusselt numbers for the walls of the enclosure increase by 2.1% in the case of two circular cylinders atRa= 106.