Turbulent flow in rough wall channels: Validation of RANS models
Turbulent flow in rough wall channels: Validation of RANS models
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DOI：
10.1016/j.compfluid.2015.08.005
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发表时间：
2015-11
影响因子：
2.8
通讯作者：
Yan Jin;H. Herwig
中科院分区：
文献类型：
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作者：
Yan Jin;H. Herwig
用标准RANS湍流模型研究了平面槽壁上两种常见的粗糙度。其目的是准确地预测通过粗糙壁通道的定常不可压缩流动的平均流量值。在基于直接数值模拟(DNS)结果的特殊验证过程中，使用了七个湍流模型，其中包括粗糙度间距和雷诺数(这里是自由参数)的几个值。除了单RANS解之外，还考察了参数展开法(PEM)在更大范围的参数范围内，即对于不同的粗糙度高度和雷诺数，准确预测粗糙壁渠道流动的能力。然后使用那些可以验证的方法来预测验证范围之外的参数的结果。它们的准确性可以通过与合理扩展的DNS结果进行比较来评估。最后得出结论：RANS解只有在一定的湍流模型和一定的参数范围内才能用于预测受壁面粗糙度影响的槽道湍流流动。
Two kinds of a generic roughness on plane channel walls have been investigated by standard RANS turbulence models. The objective was to accurately predict mean flow quantities for steady incompressible flows through rough wall channels. Seven turbulence models have been used in a special validation procedure based on direct numerical simulation (DNS) results for several values of the roughness spacing and the Reynolds number (which here are the free parameters). In addition to single RANS solutions also a parameter expansion method (PEM) is examined with respect to its capability to accurately predict rough wall channel flows for an extended range of parameters, i.e. for various roughness heights and Reynolds numbers. Those methods that could be validated were then used to predict results for parameters beyond the validation range. Their accuracy can be assessed by comparison with reasonably extended DNS results. The final conclusion is that RANS solutions only with certain turbulence models and over some parameter ranges can be used to predict turbulent channel flows influenced by wall roughness.