滩地植被化的顺直复式河道漫滩水流计算

利用二维数学模型对滩地植被化的复式河道漫滩水流的水深平均流速的分布进行了求解。通过恒定均匀流的假设,对主流方向上的沿水深积分的紊流时均运动微分方程式进行简化得到了相应的控制方程,其中引入植被对水流作用的拖曳力项,并考虑二次流的影响。同时将复式渠道划分为3个子区域,通过联立求解各区域微分方程中的定解系数,最终得到均匀流的条件下各区水深平均流速的横向分布的解析解。通过与试验测得的资料比较,表明计算结果与实测资料吻合良好。

Overbank Flow Calculation for Straight Compound Channel with Vegetated Floodplain

A two-dimensional model is used to predict the lateral variation of depth-averaged velocity of straight compound channel with vegetated floodplain in this paper.Under the hypothesis of steady uniform flow,the depth-integrated turbulence time-averaged momentum equation for the main flow direction is simplified by considering the effect of the vegetation on the flow as the drag force item as well as the secondary flows.The compound channel is divided into 3 sub-regions in transverse direction,and the coefficients in differential equations of each region are solved simultaneously.Thus the analytical solution of the transverse distribution of the depth-averaged velocity under the condition of uniform flow in vegetated floodplain compound channel is got.Compared with the experimental data,the analytical results were proved to be in good agreement with the measured data.