含植物河道紊流结构研究进展

Advances in research on turbulence structure in vegetated open channel flows

自然河流中,水生植物的存在改变了河道中的紊流结构。与普通明渠紊流相比,含植物河道水体掺混更剧烈,紊流结构更复杂。由于紊流结构直接影响河流中泥沙、污染物和营养物的输移,含植物河道紊流结构研究越来越受到重视。从紊流平均结构、紊动特性、拟序结构和紊流类型几方面归纳并总结了国内外研究进展,综合分析了影响紊流结构的因素,提出利用场与点相结合的综合分析方法,对拟序结构的形成及发展过程进行定量刻画,探究植物条件下紊流机理是今后的重要研究方向。

Aquatic plants in natural rivers have important effects on turbulence structure. In the presence of vegetation, river flows become more intensely mixed and their turbulent structures are more complicated. Many studies have been conducted recently to examine turbulence characteristics of vegetated open channel flows, which directly affect the transport of sediment, pollutants and nutrients. This work provides a review of the previous studies in the context of time-average turbulent characteristics, coherent structure, flow regime and relevant factors that influence the turbulence structure in vegetated flows. It is suggested that a combined analysis of field and point information is applied to quantitatively describe the formation and development process of coherent structure, and to explore the turbulence mechanism of vegetated flows for the further study.