DNS of Three-Dimensional Unsteady Separated Flow and Heat Transfer Around a Downward Step
DNS of Three-Dimensional Unsteady Separated Flow and Heat Transfer Around a Downward Step
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DOI：
10.1115/ht2005-72178
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
Kazuaki Sugawara;Eiji Kaihara;H. Yoshikawa;T. Ota
中科院分区：
文献类型：
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作者：
Kazuaki Sugawara;Eiji Kaihara;H. Yoshikawa;T. Ota
采用直接数值模拟方法分析了矩形通道内三维分离流动和围绕向下台阶的传热的非定常特征。使用有限差分法进行数值计算。基于入口处平均速度和台阶高度的雷诺数Re从300变化到1000。在台阶纵横比为36.0下，通道扩张比ER为2.0。研究发现，当 Re = 500 时，流动是稳定的，但在 Re = 600 时，随着流动和温度场三维度的显着增加，流动明显不稳定。努塞尔数在再附着流区域和侧壁附近达到最大值，它们的位置很大程度上取决于 Re.Copyright © 2005 by ASME
The direct numerical simulation methodology was employed to analyze the unsteady features of a three-dimensional separated flow and heat transfer around a downward step in a rectangular channel. Numerical calculations were carried out using the finite difference method. The Reynolds number Re based on the mean velocity at inlet and the step height was varied from 300 to 1000. The channel expansion ratio ER is 2.0 under a step aspect ratio of 36.0. It is found that the flow is steady upto Re = 500, but becomes sensibly unsteady at Re = 600 as accompanying a remarkable increase of the three-dimensionality of the flow and temperature fields. Nusselt number reaches its maximum in the reattachment flow region and also in the neighborhood of the side wall, and their locations depend greatly upon Re.Copyright © 2005 by ASME