Spatially averaged turbulent stress and its partitioning
Spatially averaged turbulent stress and its partitioning
复制标题
空间平均湍流应力及其分配
DOI：
10.1007/s00348-008-0463-y
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发表时间：
2008
影响因子：
2.4
通讯作者：
V. Nikora
中科院分区：
文献类型：
--
作者：
D. Pokrajac;I. McEwan;V. Nikora
基本流动方程的双重平均是研究空间非均匀流动的一种有吸引力的方法。由此产生的双平均方程可以作为一个框架的发展湍流模型。为了充分探索这种模型的潜力，作为每个平均步骤的结果出现在动量方程中的应力项需要参数化。我们调查的应力项产生的双重分解的瞬时速度。这些应力项的实验值是从实验室实验中确定的，实验涉及粗糙床上浅明渠流的PIV测量。特别注意的是，这两项一起形成的空间平均湍流应力，迄今为止还没有在文献中报道。
Double averaging of the fundamental flow equations is an attractive methodology for investigating spatially heterogeneous flows. The resulting double-averaged equations can be used as a framework for development of turbulence models. In order to fully explore the potential of such models the stress terms that appear in the momentum equation as a result of each averaging step needs to be parameterised. We investigate the stress terms resulting from the double-decomposition of instantaneous velocity. The experimental values of these stress terms were determined from the laboratory experiments involving PIV measurements of shallow open channel flows over rough beds. Special attention is paid to the two terms that together form the spatially averaged turbulent stress, which have so far not been reported in the literature.