为充分考虑泥沙起动的随机性,基于相对暴露度概率密度分布,结合瞬时水流流速及床面泥沙颗粒排列的随机特性,并采用泥沙滚动起动模型,建立了适用于散粒体及黏性细沙统一起动流速公式。通过与实测资料及经典的泥沙起动公式比较发现,本文公式计算值与实测资料吻合更好,验证了该公式在预测散粒体及黏性细沙起动流速的可靠性和优越性。
Abstract
In order to fully reflect the randomness of sediment’s incipient movement, we deduced a formula of incipient velocity suitable for both coarse and fine grains by using a sediment rolling initiation model based on the probability density distribution of dimensionless exposure degree of the grains. The stochastic characteristics of instantaneous flow velocity and sediment particle arrangement on a bed surface were also considered in this paper. Then, the incipient velocities calculated by the proposed formula were compared with measured data and those by several classical incipient velocity formulae. The results show that the incipient velocities calculated by the proposed formula are in more agreement with the measured data than those calculated by the classical formulae. Therefore, the proposed formula’s reliability and superiority in predicting incipient movement of coarse and fine sediment are testified.
关键词
泥沙 /
起动流速 /
暴露度 /
瞬时流速 /
概率统计
Key words
sediment /
incipient velocity /
exposure degree /
instantaneous velocity /
probability statistics
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] CHIEW Y M,PARKER G. Incipient Sediment Motion on Non-horizontal Slopes [J]. Journal of Hydraulic Research, 1994, 32(5): 649-660.
[2]GRASS A J. Structural Factors of Turbulence Flow over Smooth and Rough Boundary [J]. Journal of Fluid Mechanics, 1971, 50(2): 233-255.
[3]SUTHERLAND A J. Proposed Mechanism for Sediment Entrainment by Turbulent Flow [J]. Journal of Geophysical Research, 1967, 72(24): 6183-6194.
[4]APPERLY L W. Effect of Turbulent on Sediment Entrainment [D]. Auckland, New Zealand:University of Auckland, 1968.
[5] CHEN Liang,XU Ji-ting. Grain Incipient Motion considering Randomness of Grain Location[C]∥American Society of Civil Engineers. GeoHunan International Conference 2011. Hunan, China, June 9-11,2011: 322-329.
[6] 杨具瑞,方 铎,何文社,等. 非均匀沙起动规律研究[J]. 水利学报,2002,(10): 82-86.
[7] 窦国仁. 再论泥沙起动流速[J]. 泥沙研究,1999,(6): 1-9.
[8] 韩其为,何明民. 泥沙起动规律及起动流速[M]. 北京:科学出版社,1999.
[9] CHENG N S, LAW W K, LIM S Y. Probability Distribution of Bed Particle Instability[J]. Advances in Water Resources, 2003, 26(4): 427-433.
[10]YANG F G, LIU X N, CAO S Y, et al. Study on Bed Load Transport for Uniform Sediment in Laminar Flow[J]. Science China Technological Sciences, 2010, 53(9): 2414-2422.
[11]孟 震,杨文俊. 基于二维泥沙颗粒的相对隐蔽度初步研究[J]. raybet体育在线
院报,2011,28(5): 1-4.
[12]孟 震,杨文俊. 泥沙颗粒相对隐蔽度在散体沙起动研究中的应用[J].raybet体育在线
院报,2011,28(7):1-6.
[13]CHENG N S,CHIEW Y M. Pickup Probability for Sediment Entrainment[J]. Journal of Hydraulic Engineering, 1998, 124(2): 232-235.
[14]Wuhan Institute of Hydraulic and Electric Engineering (WIHEE). Review on the Einstein Theory of Bed Load Motion and Discussion on Bed Load Motion[R]. Wuhan:WIHEE, 1965:1-16.
[15]ARMANINI A,GREGORETTI C. Incipient Sediment Motion at High Slopes in Uniform Flow Condition[J]. Water Resources Research, 2005, 41(12): 1-8.
[16]周 双,张根广,梁宗祥,等. 斜坡上均匀散粒体泥沙的起动流速研究[J]. 泥沙研究,2015,(4):7-13.
[17]BRIDGE J S, BENNETT S J. A Model for the Entrainment and Transport of Sediment Grains of Mixed Sizes,Shapes and Densities [J]. Water Resources Research, 1992, 28(2): 337-363.
[18]韩其为,何明民. 泥沙运动统计理论[M]. 北京:科学出版社,1984.
[19]何文社,方 铎,杨具瑞,等. 泥沙起动流速研究[J]. 水利学报,2002,33(10): 51-56.
[20]张瑞瑾,谢鉴衡,陈文彪. 河流动力学[M]. 武汉:武汉大学出版社,2007.
[21]钱 宁,万兆惠. 泥沙运动力学[M]. 北京:科学出版社,2003.
PDF(1630 KB)
