河道漫滩及湿地上淹没柔性植物水流的紊流特性

植物在河流生态的修复中起重要作用,因此对含植物明渠水流的紊流机理的研究显得非常重要。将河漫滩及湿地中含淹没柔性植物的水流视为充分发展了的紊流,在实验室中用特定材料模拟柔性植物,通过水槽试验用三维ADV对淹没柔性植物段紊流特性进行了测量研究,对试验结果计算分析表明含淹没柔性植物的垂向流速分布不再符合指数分布;其紊流具有明显的各向异性特性;植物冠层交界处,水流紊动交换强烈,该处紊流强度及雷诺应力出现最大值。

Turbulent characteristics of flow on floodplains and wetlands with flexible vegetations

Vegetations play important role in river restoration.The flow on floodplains and wetlands with flexible vegetations is regarded as well developed turbulent flow and its turbulent characteristics are experimentally studied in laboratory.In model test the vegetations are simulated by flexible thin PVC strips and the velocity distributions are measured by 3-D ADV.The analysis on experiment result shows that the velocity distribution along the vertical line does not obey the exponential law and the flow turbulence exhibits anisotropic characteristics.It is found that strong turbulent exchange occurs to the interface at the canopies,at which the maximum Reynolds stress takes place.