植树护岸对河道水流影响的数值模拟

Numerical simulation of effect of trees planted in floodplain on water flow pattern in river

利用局部精细模拟的二维有限元数学模型对植树护岸条件下河道的水流特性进行模拟分析,结果表明:局部精细模拟更能有效考虑形状阻力,真实反映树干对流场的影响,植树后,植树区域的流场产生旋涡,并在局部地区产生滞水区,滩地的过流能力减小,主槽的流速增加,过流能力加大,并且对水位的影响小。数学模型的计算结果与实验所观测的变化规律相一致。

A two-dimensional finite element model with a local and analyze the water flow characteristics in a river channel, refined grid simulating a tree trunk was applied to simulate where trees were planted on the river bank. The results indicated that the shape resistance of the trees could be more efficiently considered with the local refined grid, and the effect of tree trunks on the flow field was factually shown by the simulation. With planted trees, vortices formed in the planting zone. Meanwhile, a water stagnation zone formed in some areas. Flow capacity in the floodplain was reduced by planted trees, while the flow rate and flow capacity in the main channel increased. The planting had little effects on the water level. The computational results corresponded with the experimental measurements.