不同人工糙率床面水力学特性的试验研究

Hydraulic Characteristics of Artificial Surfaces with Different Roughness

采用变坡试验水槽,研究了不同流量,不同坡度以及不同糙率条件下坡面流水力学参数(雷诺数、弗劳德数、平均流速、水深和阻力系数)变化规律。研究结果表明,在糙率、坡度相同情况下,坡面流的雷诺数、弗劳德数、平均流速、水深和阻力系数均随流量的增大而增大;在坡度、流量相同条件下,随着糙率的增大,坡面流的雷诺数,弗劳德数和平均流速在减小,阻力系数和水深在增大;平均流速、水深和阻力系数与流量和坡度的关系可用简单幂函数表示,而且主要由流量控制。

The variations of hydro-dynamic parameters（Reynolds number,Froude number,average flow velocity,water depth and resistance coefficient） of overland flows were characterized under different flow discharge,slope gradient and roughness based on flume experiments.The research results indicated that Reynolds number,Froude number,average flow velocity,water depth and resistance coefficient of the overland flows increased with flow discharge for the artificial beds with same roughness and slope gradient.Under the conditions of same gradient and flow discharge,Reynolds number,Froude number and average flow velocity of the overland flows decreased with increasing roughness,while resistance coefficient and flow depth increased.Flow discharge and slope gradient were found closely correlated with the hydraulic parameters such as average flow velocity,water depth,and resistance coefficient,which could be well described by simple power functions.Furthermore,the influences of flow discharge were dominant.