Analytical model of the mean velocity distribution in an open channel with double-layered rigid vegetation
Analytical model of the mean velocity distribution in an open channel with double-layered rigid vegetation
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双层刚性植被明渠平均流速分布解析模型
DOI：
10.1016/j.advwatres.2014.04.001
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发表时间：
2014-07-01
影响因子：
4.7
通讯作者：
Yang, Zhonghua
中科院分区：
文献类型：
--
作者：
Huai, Wenxin;Wang, Weijie;Yang, Zhonghua
提出了双层硬质植被明渠水流平均流速垂向分布的解析模型。双层模型是在实验室的水槽中建造的，水槽中有两个高度的钢柱阵列。对于每个植被层(即短植被层或高植被层)，水流在垂直方向上分为低植被带和上植被带，并分别建立了相应的动量方程。对于低植被带，由于湍流切变相对较小，且忽略雷诺应力，故采用均匀速度。对于上层植被带，用幂函数级数求解动量方程。对于自由水区，提出了一个新的表达式，即在水面上获得零速度梯度，而不是传统的对数速度分布。分析预测结果与实验数据吻合较好，验证了模型的有效性。(C)2014爱思唯尔有限公司。保留所有权利。
An analytical model for predicting the vertical distribution of mean streamwise velocity in an open channel with double-layered rigid vegetation is proposed. The double-layered model was constructed in a laboratory flume with an array of steel cylinders of two heights. For each vegetation layer (i.e., the short-or tall-vegetation layer), the flow is vertically separated into a lower vegetation zone and an upper vegetation zone, and corresponding momentum equations for each zone are formulated. For the lower vegetation zone, a uniform velocity was adopted since turbulent shear is relatively small and the Reynolds stress is ignored. For the upper vegetation zone, a power series was used to solve the momentum equations. For the free-water zone, a new expression was suggested to obtain a zero velocity gradient at the water surface instead of the traditional logarithmic velocity distribution. Good agreement between the analytical predictions and experimental data demonstrated the validity of the model. (C) 2014 Elsevier Ltd. All rights reserved.