为了研究明渠水流水力特性变化规律，在室内实验的基础上，采用矩形明渠变坡水槽，通过改变边壁条件、坡度和流量进行实验，得到了较好的实验数据。实验结果表明：边壁条件和坡度相同的情况下，随着流量的增加，水深呈线性增加，平均流速和雷诺数呈现幂函数增大；当Fr＜1时，弗劳德数随着流量的增加而增加；当1＜Fr＜1.526时，弗劳德数随着流量的增加先增加而后减小；当Fr＞1.526时，弗劳德数随着流量的增加而减小；曼宁糙率系数随着流量的增加呈对数减小趋势。边壁条件和流量相同的情况下，随着坡度的增大，水深呈减小趋势，平均流速、雷诺数、弗劳德数和曼宁糙率系数均呈现增加的趋势。并由实验数据得出了雷诺数与坡度和流量的经验公式

In order to investigate hydraulic characteristics of open channel flow, based on indoor experiments, rectangle open channel with different slope rates were used, and the conditions of the side walls, slope angle and flux were changed to obtain experiment data. The experimental results showed that: under the same condition, the water depth increased linearly with the increase of flow rate, and the average flow velocity and the Reynolds number increased with the increase of the flow rate. The Froude number increased with the increase of the flow rate when Fr＜1. With the increase of the flow rate, the Froude number increased and then decreased when 1＜Fr＜1.526，and decreased gradually when Fr＞1.526. The Manning roughness coefficient decreased with the increase of flow rate. In the case of the same condition and the same flow rate, with the increase of slope, the water depth decreased, and the average flow velocity, Reynolds number，Froude number and Manning roughness coefficient increased. The empirical formula of Reynolds number and gradient and flow rate was obtained by the experimental data.

国家自然科学基金项目（51009102）；青年基金项目（51179133）