In this experimental work, flow force in compound channel in presence of non-submerged vegetation was obtained via direct measurement method. The direct measurement method was used to address the inefficiency of the conventional energy-based methods for measuring the force within the body of highly rough flows. On this basis, the study was performed using a specially designed flume called knife-edge flume with a length of 14 m, a width of 1.07 m, and a height of 1.05 m at a stream bed grade of 10^-3. The flow force measurements were performed directly using a load cell in absence of the common errors that were otherwise associated with velocity measurement by inserting an external body into the flow. In this study, we examined non-submerged rigid vegetation layers with five different diameters (i.e., 20, 25, 30, 40, and 50 mm), three values of crossline spacing (i.e., 6, 8, and 10 cm), five values of crossline spacing (i.e., 8, 10, 12, 15, and 20 cm), and two different arrangements (i.e., ordered and non-ordered or cruciform) at three different positions (i.e., in the floodplain, in the main channel, and simultaneously in the floodplain and the main channel) by performing a total of 451 tests. The flow force exhibited the highest sensitivity to the increase in vegetation volume under the non-ordered arrangement. In this respect, the improvement in the flow force with increasing the percent volume of vegetation was much larger when the vegetation was arranged in a non-ordered rather than ordered fashion, with the effect of the vegetation been even more pronounced in the floodplain rather than the main channel. In addition, at a certain percent change of the flow force, the trough-vegetation flow velocity was higher under the ordered arrangement rather than the non-ordered arrangement, reflecting the more difficulty encountered by the flow as it passed through the non-ordered vegetation. Based on the analysis results, it was found that the flow force would change by 060% when the vegetation had grown in the floodplain with λ* values in the range of 0–1. In cases where the vegetation had grown in the main channel and simultaneously in the main channel and the floodplain, the flow force variations increased to 10–70% and 20–80% as the λ* changed from 0 to 10, respectively. Analyzing the results of the experiments and the vegetation-modified Reynolds number, a relationship was further presented for calculating the flow force in presence of non-submerged rigid vegetation in a compound channel.

在这项实验工作中，通过直接测量方法获得了在没有淹没植被的情况下复合通道中的流动力。直接测量方法用于解决传统的基于能量的方法的效率低下问题，该方法无法测量高度粗糙的流体在体内的作用力。在此基础上，使用特殊设计的水槽（称为刀刃水槽）进行了研究，该水槽的水床等级为10 ^-3，长度为14 m，宽度为1.07 m，高度为1.05 m 。在没有常见误差的情况下，直接使用称重传感器直接进行了流力测量，而这些误差通常通过将外部物体插入流中而与速度测量相关。在这项研究中，我们检查了具有五个不同直径的非淹没刚性植被层（即20、25、30、40和50毫米），三个交叉线间距值（即6、8和10厘米），五个交叉线间距值（即8、10、12、15和20）厘米），和两个不同的布置（即，有序，在三个不同位置的非有序的或十字形）（即，在洪泛区，主渠道中，同时在洪泛区和主渠道中），共执行451次测试。在无序排列下，流动力对植物体积的增加表现出最高的敏感性。在这方面，当以非有序而不是有序的方式排列植被时，随着植被体积百分比的增加，流动力的改善要大得多，在洪泛区而不是洪泛区，植被的影响更加明显。主要渠道。此外，在一定的水力变化百分比下，有序布置下的槽-植被流速要高于无序布置，这反映了水流通过无序植被时遇到的困难更大。 。根据分析结果，发现当植被在洪泛区中生长且λ*值在0-1范围内时，流动力将发生060％的变化。在植被在主河道以及在主河道和洪泛区同时生长的情况下，当λ*从0变为10时，流动力变化分别增加到10-70％和20-80％。分析实验结果和植被修正的雷诺数，进一步提出了一种关系，用于计算复合渠道中存在非淹没的刚性植被时的流动力。在植被在主河道以及在主河道和洪泛区同时生长的情况下，当λ*从0变为10时，流动力变化分别增加到10-70％和20-80％。分析实验结果和植被修正的雷诺数，进一步提出了一种关系，用于计算复合渠道中存在非淹没的刚性植被时的流动力。在植被在主河道以及在主河道和洪泛区同时生长的情况下，当λ*从0变为10时，流动力变化分别增加到10-70％和20-80％。分析实验结果和植被修正的雷诺数，进一步提出了一种关系，用于计算复合渠道中存在非淹没的刚性植被时的流动力。