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坡面流阻力的研究对于深入认识坡面流水力特性及土壤侵蚀产沙机理具有重要意义。采用变坡试验水槽,利用定床阻力冲刷试验系统研究了坡面流Darcy-Weisbach阻力系数与粗糙度、流量、坡度和水流型态之间的关系。结果表明:阻力系数随着床面粗糙度的增加呈指数函数增大;阻力系数随着雷诺数的增加呈幂函数减小,且随粗糙度的增加;阻力系数与弗劳德数呈良好幂函数关系,且粗糙度的影响不显著,流量为主要影响因素;人工模拟粗糙度床面下,阻力系数可由粗糙度、流量和坡度的简单幂函数良好表示,并且粗糙度为主要影响因素,流量和坡度的影响相对较小。由因子分析可知,阻力系数可由粗糙度和弗劳德数良好表示,经检验该模型可用来计算不同粗糙度坡面薄层水流的阻力系数。
The study of slope flow resistance is of great significance for understanding the hydraulic characteristics of slope flow and the mechanism of soil erosion and sediment yield. The relationship between the Darcy-Weisbach drag coefficient and the roughness, the flow rate, the gradient and the water flow pattern was studied by using a variable slope test tank and a fixed-bed resistance scouring test system. The results show that the drag coefficient increases exponentially with the increase of the roughness. The drag coefficient decreases with the increase of Reynolds number, and decreases with the increase of roughness. The drag coefficient and Froude number show a good power Function, and the influence of roughness is not significant. The flow rate is the main influencing factor. Under artificial simulated roughness bed, the drag coefficient can be well represented by the simple power function of roughness, flow rate and slope, and the roughness is the main influencing factor. The flow rate And the slope of the impact is relatively small. The factor analysis shows that the drag coefficient can be well represented by the roughness and the Froude number. The model can be used to calculate the drag coefficient of thin-layer water flow on different roughness slopes.