水利学报
水利學報
수리학보
2014年
10期
1184-1192
,共9页
粗颗粒%滚动%推移质输沙率
粗顆粒%滾動%推移質輸沙率
조과립%곤동%추이질수사솔
coarse particles%transport rate%bedload rolling
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。
卵石推移質運動規律研究對山區河流開髮利用意義重大。推移質顆粒一般是以滾動(間或滑動)、躍移等形式運動的。在低水流彊度範圍內,顆粒運動形式以滾動為主;即使佔推移質大部分的躍移顆粒,通常也併不是在起動之後隨即躍起,而往往需要先滾動一段距離。因此,有必要進行泥沙顆粒滾動機理研究。本文建立瞭粗顆粒泥沙滾動力學模型,將滾動步劃分為接觸步和自由步,經計算得到脫離角、單步運動步長、平均滾動速度等錶達式;併採用愛因斯坦方法,脩正瞭其公式中的單步步長和遲刷率,進而得到相應的推移質輸沙率公式,併用實際輸沙率資料進行瞭驗證。
란석추이질운동규률연구대산구하류개발이용의의중대。추이질과립일반시이곤동(간혹활동)、약이등형식운동적。재저수류강도범위내,과립운동형식이곤동위주;즉사점추이질대부분적약이과립,통상야병불시재기동지후수즉약기,이왕왕수요선곤동일단거리。인차,유필요진행니사과립곤동궤리연구。본문건립료조과립니사곤동역학모형,장곤동보화분위접촉보화자유보,경계산득도탈리각、단보운동보장、평균곤동속도등표체식;병채용애인사탄방법,수정료기공식중적단보보장화충쇄솔,진이득도상응적추이질수사솔공식,병용실제수사솔자료진행료험증。
Gravel bedload transport is of great significance to the development and utilization of mountain?ous 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. There?fore, 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 sin?gle-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.