Direct numerical simulation of turbulent flow over a rough surface based on a surface scan
Direct numerical simulation of turbulent flow over a rough surface based on a surface scan
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基于表面扫描的粗糙表面湍流的直接数值模拟
DOI：
10.1016/j.compfluid.2015.04.008
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发表时间：
2015
影响因子：
2.8
通讯作者：
Busse A
中科院分区：
文献类型：
--
作者：
Busse A
典型的工程粗糙表面只显示出有限的相似性，人工建造的粗糙表面，已成为大多数以前的基础研究粗糙壁湍流。在这篇文章中，通过一个粗糙的石墨表面，作为一个典型的例子，在工程应用中发现的不规则粗糙表面的扫描的基础上，流动过去的不规则粗糙表面进行了研究。在傅立叶空间中过滤表面高度与横向坐标的扫描图，以去除非常小尺度上的特征，并创建表面的平滑变化的周期性表示。在槽道湍流的直接数值模拟中，该表面被用作无滑移边界。对于不规则边界的分辨率迭代嵌入边界方法。通过研究一系列过滤程度递减的表面，研究了表面过滤对湍流的影响。平均流量，雷诺应力和分散应力分布显示出良好的协议，一旦足够大的傅立叶模式的数量被保留。然而，如果仅分辨最大的表面特征，则观察到显著差异。强过滤的表面引起更高的平均流速和更高的变化的流向速度在粗糙层相比，弱过滤的表面。与此相反，对于弱过滤表面的平均流量是反向的粗糙度子层的下部的大部分和较高水平的分散剪应力被发现。
Typical engineering rough surfaces show only limited resemblance to the artificially constructed rough surfaces that have been the basis of most previous fundamental research on turbulent flow over rough walls. In this article flow past an irregular rough surface is investigated, based on a scan of a rough graphite surface that serves as a typical example for an irregular rough surface found in engineering applications. The scanned map of surface height versus lateral coordinates is filtered in Fourier space to remove features on very small scales and to create a smoothly varying periodic representation of the surface. The surface is used as a no-slip boundary in direct numerical simulations of turbulent channel flow. For the resolution of the irregular boundary an iterative embedded boundary method is employed. The effects of the surface filtering on the turbulent flow are investigated by studying a series of surfaces with decreasing level of filtering. Mean flow, Reynolds stress and dispersive stress profiles show good agreement once a sufficiently large number of Fourier modes are retained. However, significant differences are observed if only the largest surface features are resolved. Strongly filtered surfaces give rise to a higher mean-flow velocity and to a higher variation of the streamwise velocity in the roughness layer compared with weakly filtered surfaces. In contrast, for the weakly filtered surfaces the mean flow is reversed over most of the lower part of the roughness sublayer and higher levels of dispersive shear stress are found.
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波状壁对湍流中被动标量传输的影响
DOI：
--
发表时间：
2008
期刊：
影响因子：
--
作者：
S. Kuhn;C. Wagner;P. R. von Rohr
通讯作者：
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影响因子：
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作者：
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作者：
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作者：
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通讯作者：
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影响因子：
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作者：
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