规则波作用下刚性挺水植物波生流试验研究

通过在波浪水槽中进行一系列物理模型试验研究规则波作用下刚性挺水植物波生流特性，测试了2种水深和不同入射波况条件下的波生时均流速并对比了挺水植物有茎与无茎时波生流的情况，基于假设检验分别对挺水植物的拖曳力长度尺度、植物特征参数建立模型。研究结果表明:在茎密度为60株/m2时，波生流仍以根部作用为主要因素，对沉水植物公式进行拓展，据此提出挺水植物时均流速最大值预测公式；茎部对时均流速均方根具有衰减作用，且茎部在根部及根部上方区域产生的相对衰减强度，与厄塞尔数呈抛物线函数关系；在簇状根系分布下，茎部对垂向流速结构起稳定作用，尤其是在时均流速最大值所对应的量纲一垂直位置。

Experimental study of the wave-induced current for emergent rigid vegetation under regular wave conditions

To understand the variation of the wave-induced current for emergent rigid vegetation, a series of laboratory experiments were conducted in a wave flume with two water depths, a variety of regular wave conditions, and two emergent plants modes. Based on the hypothesis testing, the predicting models for the canopy-drag length and the characteristic vegetation parameters were established respectively. The results showed that the current is predominantly induced by the root when the stem density was 60 plants/m2. Based on this observation, a model for predicting the maximum temporal-averaged flow for emergent vegetation was proposed by the extension of the existing model derived from submerged vegetation. The stem can reduce the root-mean-square of the mean current, the relative reduction constant at and above the root was a parabolic function of Ursell number. In the distribution of cluster roots, the stem had a stabilizing influence on the vertical velocity structure, especially at the normalized vertical position corresponding to the maximum of the temporal-averaged flow velocity.