含植物明渠流动分区和特征尺度研究进展

植物是生态河流必不可少的要素之一。植物的存在,改变了水流的紊流结构。由于流动沿垂向具有较强的不均匀性,对于含植物明渠紊流统计特性的描述,至今未有公认的、统一的沿水深分布表达形式。因此,对含植物明渠流动分区和各区特征尺度的研究越来越受到重视。本文回顾了无植物明渠和含植物明渠流动分区及特征尺度研究的主要成果,重点对基于流速分布和紊流结构两种方法确定的分区和特征尺度进行了分析和总结。指出将涡结构与流动特性参数分布规律相结合进行流动分区,在各区确定合适的特征尺度,进一步探究分区界限及流动特征尺度的影响因素及具体影响,建立普适的紊流统计特性分布规律是今后含植物明渠紊流结构研究的重要内容和趋势。

Advances in research on sub-division and characteristic scales of open channel flows with vegetation

Vegetation is an essential element in most natural ecological rivers. Its biological characteristics change turbulent structures of the river significantly. Due to the strong inhomogeneity of flow in the vertical direction, there still are no universal expressions of the turbulent statistical properties along water depth in vegetated open-channel flows. Therefore, flow sub-division and corresponding characteristic scales of these regions have gained more focuses. In this paper, the research achievements of sub-division and characteristic scales are reviewed in terms of traditional and vegetated open-channel flows. The results based on the velocity distribution and turbulent structures are analyzed and summarized respectively. The paper proposes that to partition the flow into different sub-regions by combining the vortex structure with the distribution of flow characteristic parameters,determine the appropriate characteristic scales of each sub-regions and investigate the influence factors of sub-division and characteristic scales are the main research contents and tendencies.