Drag coefficient and averaged Nusselt number of a scalene prolate ellipsoid
Drag coefficient and averaged Nusselt number of a scalene prolate ellipsoid
复制标题
DOI：
10.1016/j.apm.2018.07.055
复制
发表时间：
2018-12
影响因子：
5
通讯作者：
Chunhai Ke;S. Shu;Hao Zhang;Hai-Zhuan Yuan
中科院分区：
文献类型：
--
作者：
Chunhai Ke;S. Shu;Hao Zhang;Hai-Zhuan Yuan
利用三维浸没边界格子Boltzmann模型（IB-LBM）对冷流体流过热的定常不等边长椭球体进行了数值研究。首先，轴对称椭球体被认为是用于验证的目的，并得到的阻力系数（Cd）和平均努塞尔数（Nu）和以前报道的结果之间的良好协议。随后，通过改变椭球体的形状（2 ≤ Ar 1，Ar 2 ≤ 6）、入射角（0° ≤θ≤ 90°）以及雷诺数（25 ≤Re≤ 200），进行了81个算例的计算。在这项研究中，我们特别考虑不等边长椭球与不等Ar 1和Ar 2，这还没有被详细研究过。通过对数值结果的分析，了解了不同因素对固液两相间动量和传热特性的影响。文献中报道的可用公式也作了简要回顾。最后，用最重要的因子建立了Cd和Nu的新关联式，Cd和Nu的平均偏差分别为3.875%和1.598%。这些关联式可用于多相流模拟中的相耦合。
A cold fluid flowing past a hot stationary scalene prolate ellipsoid is numerically studied via a three-dimensional immersed boundary-lattice Boltzmann model (IB-LBM). First, axisymmetric ellipsoids are considered for verification purposes, and good agreement is found between obtained drag coefficient (Cd) and averaged Nusselt number (Nu) and previously reported results. Subsequently, 81 case studies are conducted by changing shape (2 ≤Ar1,Ar2 ≤ 6) and incident angle (0° ≤θ≤ 90°) of the ellipsoid as well as the Reynolds number (25 ≤Re≤ 200). In this study, we particularly consider scalene prolate ellipsoids with unequalAr1 andAr2, which have not been studied in detail before. Effects of different factors on momentum and heat transfer characteristics between solid and fluid phases are understood based on the analysis of numerical results. Available formulas reported in the literature are also briefly reviewed. Finally, new correlations for bothCdandNuare developed using the most important factors with average deviations of 3.875% forCdand 1.598% forNu, respectively. These proposed correlations can be used to facilitate the phase coupling in the multi-phase flow modelling.