湿地非淹没芦苇水流阻力的试验研究

Roughness coefficient of non-submerged reed

对松嫩流域湿地主要植物芦苇在非淹没流条件下的阻力特性进行了水槽模型试验;利用恒定非均匀流水力参数的基本关系,由实测水面线计算芦苇阻力的底面等效剪应力,进而确定等效曼宁系数;试验结果表明非淹没芦苇的等效曼宁系数和水深成线性关系,它和流速的大小基本无关;还给出了Darcy Weisbach系数与水深的关系及曼宁系数与作用在三维单元水体上芦苇阻力间的关系。

A laboratory experiment has been conducted in a water flume to measure the roughness coefficient of the non-submerged reed that is the main vegetation on Song Nen River Basin. Using the relationship between the parameters of the steady non uniform flow the equivalent bed shears are calculated with the measured water depths and from which the Manning’n is determined. Test results reveal that the Manning’n is independent of the mean velocity and is linear with the flow depth. The Darcy-Weisbach friction factor f and the drag force on an element FDE in three-dimensional flow are converted from the Manning’n.