基于泥沙悬浮高度假设的恢复饱和系数研究  

Study on the Saturation Recovery Coefficient of Suspended Sediment Based on the Hypothesis of Suspension Height

作　　者：杨永杰 张根广[1] 许晓阳 YANG Yongjie;ZHANG Genguang;XU Xiaoyang(College of Water Resources and Architectural Engineering,Northwest A&F University,Yangling,Shaanxi 712100,China)

机构地区：[1]西北农林科技大学水利与建筑工程学院,陕西杨凌712100

出　　处：《水利与建筑工程学报》2023年第3期30-36,104,共8页Journal of Water Resources and Architectural Engineering

基　　金：国家自然科学基金项目(51879227)。

摘　　要：针对大坝下游单向冲刷条件下次饱和挟沙水流的恢复饱和系数取值问题,基于泥沙悬浮高度假设,采用理论推导与对比验证的方法对恢复饱和系数公式进行了分析研究。分析了泥沙颗粒在挟沙水流中的动力机理和能量转换过程,推导了泥沙颗粒的单步悬浮高度和步长公式,改进了恢复饱和系数公式。采用经典的恢复饱和系数公式和黄河非均匀沙恢复饱和系数率定值,与改进的恢复饱和系数公式进行了对比分析。结果表明:改进的公式可以较好的预测恢复饱和系数,粒径0.025 mm~1.5 mm泥沙的恢复饱和系数在1.9 cm/s~100.0 cm/s的摩阻流速范围内取值在0.01~3.00之间,恢复饱和系数随摩阻流速的变化规律也随泥沙粒径的不同而不同。Aiming at the problem of the value of saturation recovery coefficient of subsaturated sediment-laden flow under the condition of unidirectional scour downstream of the dam,based on the hypothesis of suspension height of sediment particles,the formula of saturation recovery coefficient is analyzed and studied by means of theoretical derivation and comparative verification.The dynamic mechanism and energy conversion process of sediment particles in sediment-laden flow are analyzed,the formulas of single-step suspension height and step length of sediment particles are derived,and the formula of saturation recovery coefficient is improved.The classical formula of saturation recovery coefficient and the value of saturation recovery coefficient of non-uniform sand in the Yellow River are compared with the improved formula of saturation recovery coefficient.The results show that the improved formula can better predict the saturation recovery coefficient,and the saturation recovery coefficient of particle size 0.025 mm~1.5 mm sediment is between 0.01 and 3 within the friction velocity range of 1.9 cm/s~100 cm/s,and the variation law of saturation recovery coefficient of different particle size sediment is different with the friction velocity.

关 键 词：恢复饱和系数 不平衡输沙 悬移质 非均匀沙 悬浮高度 

分 类 号：TV142[水利工程—水力学及河流动力学]