摘要
珠江河口峡口岬角地形(或者称"门")是珠江河口典型的高能耗区,研究其消能机制,对于解释珠江河口宏观动力现象,提高对河口动力过程的认识有重要意义。本文设计了峡口岬角局部突变地形的湍流能耗特性物理模型试验,采用Son Tek 16MHz ADV采集了高频流速数据,统计了时均流速及湍流特征量。利用"惯性耗散法"计算了峡口岬角突变地形与明渠水流的湍流动能耗率。峡口岬角地形的突变特征产生明显的形态阻力,本文试验工况引起的紊动强度量值是明渠的2倍到10多倍,湍流剪切应力较明渠水流大近2个数量级,湍流动能是明渠水流的40多倍,湍流动能耗散率比明渠水流湍流动能耗散率大2~3个数量级。从湍流局部平衡及能量传递理论看,峡口局部形态阻力导致时均流速的空间梯度、切应力增大及形成大量更小尺度的涡是湍流能耗率增加2~3个量级的重要原因。
The throat topography ( or called "gate" ) is a typical high energy consumption zone at Pearl River Estuary. Research on the turbulent kinetic energy dissipation induced by the throat topography is important to the explanation of the Pearl River Estuary dynamic phenomenon and understanding of dynamic estuarine processes. A physical model was designed for study of turbulent energy dissipation induced by throat topography. The high frequency velocity was collected by SonTek 16MHz ADV. Turbulent energy dissipation was calculated by inertial dissipation method for channel flow and jet flow induced by the throat topography. Turbulent energy dissipation induced by the throat topography is 100 - 1000 times than that in common channel. From the local turbulent equilibrium and energy transfer theory, the higher spa- tial gradients of velocity , turbulent stress and more smaller scale eddies produced by the throat topography is the important reasons that make the turbulent energy dissipation rate increase 2 - 3 order of magnitude.
出处
《水资源与水工程学报》
2016年第2期128-134,共7页
Journal of Water Resources and Water Engineering
基金
广东水利科技创新项目(2016-12)
关键词
峡口地形
湍流能耗
物理模型试验
惯性耗散法
throat topography
turbulent energy dissipation
physical model test
inertial dissipation method