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为探求多沙粗沙区沙黄土坡面细沟侵蚀发生过程中的水动力学特性,研究了3种坡度(3°、9°、15°)、5种流量(2.4L/min、3.6L/min、4.8L/min、6.0L/min、7.2L/min)组合冲刷试验的坡面细沟水力要素的变化规律。结果表明,沙黄土细沟水流平均流速和放水流量与水力坡度间存在幂函数关系;试验床面形态属于动平床过渡区,土壤黏粒含量愈大,沟床愈趋向于低能态区延伸,随着中值粒径的增加水流愈向高能态区发展。弗劳德数变化在0.96~1.30之间,水流流态多属于急流;雷诺数主要在307~1 465之间变化,属于过渡区范畴;阻力系数与雷诺数之间并无显著关系,主要与床面中值粒径或者黏粒含量有关,与明渠水流中紊流粗糙区的阻力特征比较类似,根据阻力特征分析,含沙水流已进入阻力平方区。
In order to explore the hydrodynamic characteristics of rill erosion in sandy loess area, three slopes (3 °, 9 °, 15 °), five flow rates (2.4L / min, 3.6L /min, 4.8L / min, 6.0L / min, 7.2L / min) combined erosion test. The results show that there is a power function relationship between average velocity of flow in rill water flow and hydraulic slope. The bed surface morphology belongs to dynamic transition zone. The larger the clay content is, the more ditch bed extends to low energy state zone. Increasing the median particle size increases the flow of water towards higher energy states. The Froude number changes between 0.96 and 1.30, and the water flow is mostly in the form of jet stream. The Reynolds number mainly changes between 307 and 1465, which belongs to the transitional area. There is no significant relationship between the drag coefficient and the Reynolds number, Bed median diameter or clay content, and the open channel flow turbulence rough area of resistance characteristics are similar, according to the analysis of resistance characteristics, sandy water flow into the resistance square area.