Morphological properties of two-dimensional and three-dimensior bedforms in open channel flow: A flume experiments study  

作　　者：Wenhong Cao Xu Geng Chunjing Liu Lingfeng Zhang 

机构地区：[1]State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,Beijing 100048,China [2]Key Laboratory of Sediment Science and Northern River Training of Ministry of Water Resources,Beijing 100048,China [3]China Institute of Water Resources and Hydropower Research,Beijing 100048,China

出　　处：《International Journal of Sediment Research》2025年第1期15-30,共16页国际泥沙研究(英文版)

基　　金：The current research has been supported by the National Natural Science Foundation of China(Grant Nos.12072373,51679260);the China Institute of Water Resources and Hydropower Research(IWHR)R&D Support Programs(Grant No.SE0145B022021).

摘　　要：Bedforms are formed by sediment particles under the action of flow,which in turn affect flow and sediment movement.However,the fundamental mechanisms behind the formation and development of bedforms under varying flow conditions,the interconnection between sediment particle movement and bed morphology development,as well as the influence of bedforms on flow and sediment transport,are still not well understood.In the current study,the moveable bed load transport flume experiments under different flow conditions were done,and the development processes of two-dimensional and three-dimensional dunes formed under different flow intensities were simulated.The detailed structure of the bedforms was measured by laser scanning technology,the characteristics of the bedforms were analyzed in detail,and the relations between the formation of the bedforms and the movement of sediment particles are discussed.The results found that the correlation coefficients of the longitudinal profile curve can serve as a quick reference for distinguishing two-dimensional and three-dimensional dunes.When the crestline ratio is used as the criterion for two-dimensional and three-dimensional dunes,the relative amplitude of the dune crestline and the included angle with the flow direction should also be comprehensively considered.The lee side angles of dunes calculated using the triangle generalization method and local section tangent method are compared and show that the values ob-tained by the former method are only about half of that of the latter.It is also found that the lee side angles of dunes are related to the dune height.The superimposed dunes generally exist in the down-stream area of the stoss side of the dunes.The local bed slopes on the stoss side of the dunes show reverse slopes.The superimposed dunes improve the local bed height and further increase the reverse slope degree of the stoss side.A streamwise ridge is an important form located in the upstream area of the dunes stoss side,and they are symmetrically distributed on both

关 键 词：BEDFORMS DUNES BEDLOAD Flow structure Sediment transport 

分 类 号：P73[天文地球—海洋科学]