河漫滩湿地淹没柔性植物水流涡量场研究  

Vortex field of flow over floodplain and wetland with submerged flexible vegetation

作　　者：吴福生[1,2] 姜树海[1,2] 周杰[1,2] 王勇[1,2] 

机构地区：[1]水文水资源及水利工程科学国家重点实验室,江苏南京210098 [2]南京水利科学研究院,江苏南京210029

出　　处：《水利学报》2010年第12期1469-1475,共7页Journal of Hydraulic Engineering

摘　　要：含植物水流的涡量场构成了河漫滩湿地水生物生境的物理基础,形成水、营养物质的循环以及能量的分配过程。本文通过玻璃水槽试验用二维标准PIV测量研究了含淹没柔性植物二维垂直涡量场的分布。研究表明:流速梯度是形成含植物水流涡量的关键因素,水流过植物冠层附近受到的干扰大,因而流速梯度大;涡量最大值出现在淹没柔性植物冠层以下约50%处;植物冠层处,涡量绝对值大,拟熵大,能量耗散率也高。植物冠层是造成水流紊动耗散的主要原因。The two dimensional vertical vortex of flow over flood plain with submerged flexible vegetation were studied by using PIV in flume test. The velocity gradient is the main factor affecting the vortex formed by vegetation. The flow disturbance is very large near the coronal region of submerged flexible vegetation, and resulted in significant velocity gradient. The maximum vortex occurred at the layer about 50% of the relative vegetation height. At the vicinity of coronal layer, the absolute value of vortex is large, the imitate entropy is high, and the energy dissipation rate is large. The coronal layer of submerged flexible vegetation is the major factor affecting the turbulent diffusion.

关 键 词：涡量场 河漫滩 湿地 淹没柔性植物 流速梯度 拟熵 能量耗散率 紊动扩散 

分 类 号：TV133[水利工程—水力学及河流动力学]