| 徐海珏,沈颖,白玉川.推移质滚动的机理及统计规律[J].水利学报,2014,45(10): |
| 推移质滚动的机理及统计规律 |
| Statistical analysis on motion characteristics of bedload rolling |
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| DOI： |
| 中文关键词: 粗颗粒 滚动 推移质输沙率 |
| 英文关键词: coarse particles transport rate bedload rolling |
| 基金项目: |
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| 中文摘要: |
| 卵石推移质运动规律研究对山区河流开发利用意义重大。推移质颗粒一般是以滚动（间或滑动）、跃移等形式运动的。在低水流强度范围内，颗粒运动形式以滚动为主；即使占推移质大部分的跃移颗粒，通常也并不是在起动之后随即跃起，而往往需要先滚动一段距离。因此，有必要进行泥沙颗粒滚动机理研究。本文建立了粗颗粒泥沙滚动力学模型，将滚动步划分为接触步和自由步，经计算得到脱离角、单步运动步长、平均滚动速度等表达式；并采用爱因斯坦方法，修正了其公式中的单步步长和冲刷率，进而得到相应的推移质输沙率公式，并用实际输沙率资料进行了验证。 |
| 英文摘要: |
| Gravel bedload transport is of great significance to the development and utilization of mountainous rivers. Generally， the bed particles may perform rolling， sliding or saltating motions depending on flow and bed conditions. In low flow intensity range， rolling is the main form of movement； even the saltation particles which account for the majority of bedload usually need to roll some distance before leaps. Therefore， it is necessary to carry some research into rolling sediment particles. On the basis of analyzing the forces of one rolling particle，a mechanical model was built which divided a single-step movement into two
parts， i.e. touching movement and free movement. Then expressions for the rate and distance of a single-step movement were obtained by methods of numerical calculation and regression analysis. Finally by modifying the erosion probability of particles and the dimensionless step length used in Einstein's bedload function transport rate formula was derived and validated with actual measured data. |
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