中层温差反坡异重流运动特性试验研究

以三峡水库支流库湾长期普遍存在的中层倒灌异重流为背景,构建室内物理模型,以入流量、初始水位、温度差3个主要影响因子,设计系列工况对中层反坡异重流运行特性进行模拟试验研究,分析异重流头部移动速度、交界面高度、头部厚度等主要水力学要素的变化过程及受入流量、初始水位、温度差的影响规律。借助钱宁等有关异重流的头部速度理论公式,计算了各种工况下的中层异重流头部理论速度,对比实际头部速度的实测值与理论值,两者相差不大,相对误差均小于5%。

Motion Characteristics of Mid-layer Adverse Slope Density Current

With the widespread long-term mid-layer intrusion density flow in the tributary bays of Three Gorges Reservoir as a research background, an indoor physical model was built. Three main factors inflow rate, initial water level, and temperature difference were chosen to design various conditions to simulate and investigate the motion characteristics of adverse slope density current in the mid-layer. The variations of hydraulic elements of the density current such as head moving velocity, interface height and head thickness influenced by inflow rate, initial water level, and temperature difference were analyzed. With Channing’s theoretical formulas, the head velocities of mid-layer density current in different conditions were calculated and compared with the measured values. It was found that the difference between the two was not large, and the relative error was less than 5%.