水生植物环境中,水流受植被的阻碍作用,流动阻力增加。为了定量研究植被对水流的阻力,本文采用应力计对非淹没刚性植被的流动阻力进行了实验室测量。能量方程计算的拖曳力与应力计实测的拖曳力进行了对比,两者的一致性证明了拖曳力测力装置的有效性。对不同水深条件下的植被拖曳力的测量表明,非淹没刚性植被的流动阻力与速度的平方成正比,拖曳力系数受雷诺数和能量底坡的影响较大。
The flow resistance in the environment with aquatic vegetation increases due to the retardance of vegetations.To quantitatively study the effects of vegetation acting on the flow,a series of laboratory drag measurement were conducted in open channel flow with emerged rigid artificial vegetations.The drag obtained by strain gauges was compared with the calculation result using the energy equation,and good agreement was attained.The drag force measured for different water depth is linearly related with the square of the area-averaged velocity,and the drag coefficient is clearly affected by Reynolds number and energy slope.