刚性植被密度对岸滩作用的数值模拟

Numerical simulation of effect of rigid vegetation density on banks and beaches

岸滩修复工程通常会利用植被来增加岸边的稳定性。为研究刚性植被对水流、床面形态的影响,以圆柱代替刚性植被进行了不同植被密度下的植被-水流-泥沙数值模拟研究,并分析了植株周围水流流速、床面切应力与植被密度的关系。结果表明:1)数值模拟流速结果与试验结果较为吻合。2)随着植被密度的增加,流速、床面切应力均呈现先增大后减小的规律。3)床面形态变化规律显示,当植被密度增加到一定程度时,整体形成沙脊的现象不那么明显,而是以单根植被下游近区的局域沙堆出现。

Beach restoration projects often use vegetation to increase the shore stability.In order to study the influence of rigid vegetation on hydrodynamics and morphology,the cylinder is used instead of rigid vegetation to carry out a numerical simulation study of vegetation-flow-sediment under different vegetation densities,and the relationship of vegetation density with the velocity and bed shear stress is analyzed.The results shows that:1)The numerical simulation flow velocity is consistent with experimental data.2)With the increase of vegetation density,the velocity and bed shear stress increase first and then decrease.3)The bed morphology change law shows that the overall formation of sand ridge is not so obvious when the vegetation density increases to a certain degree,but appears as a local sand pile near the lower reaches of the single vegetation.