流量和坡度对植被水流水动力学特性的影响

发布时间：2019-01-04 20:28

【摘要】：为深入揭示植被覆盖下坡面流阻力的内在规律,系统研究了植被覆盖度为32.32%时6个坡度和12个流量组合下坡面流的流动特性。结果表明:坡面流速随流量的增大而增大,该覆盖度下流态指数值接近1;坡面流从层流变化成过渡流,最后发展成紊流状态,但植被覆盖下坡面流的层流状态与明渠定义的不同;阻力系数随流量的增大而增大,流量是影响阻力的主要因素,而坡度对其影响可以忽略;阻力系数随平均水深和壅降差的增大而增大,壅降差不仅能代表水深对阻力系数的影响,而且能反映植被前壅水和后尾水旋涡的形成程度。
[Abstract]:In order to reveal the inherent law of slope flow resistance under vegetation cover, the flow characteristics of slope flow under the combination of 6 slopes and 12 flows with vegetation coverage of 32.32 were systematically studied. The results show that the flow velocity increases with the increase of flow rate, and the value of flow state index under this coverage is close to 1. The slope flow changes from laminar flow to transitional flow, and finally develops into turbulent state, but the laminar flow state of slope flow under vegetation cover is different from the open channel definition. The resistance coefficient increases with the increase of the flow rate, and the flow rate is the main factor affecting the resistance, but the influence of the slope on it can be neglected. The drag coefficient increases with the increase of the average water depth and the drop difference of the backwater, which can not only represent the influence of the water depth on the drag coefficient, but also reflect the formation degree of the vortex in the backwater before vegetation and in the rear tail water.
【作者单位】：西北农林科技大学水利与建筑工程学院;中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点试验室;
【基金】：国家自然科学基金资助项目(51579214,51209222,41001159) 国家“973”计划项目(2015CB040441) 国家级大学生科技创新训练计划项目(201410712082) 黄土高原土壤侵蚀与旱地农业国家重点实验室开放基金资助项目(K318009902-1413) 流域水循环模拟与调控国家重点实验室开放基金资助项目(IWHR-SKL-2014)
【分类号】：S157

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