MODELING OF SEDIMENT TRANSPORT IN CHANNELS WITH GRADUALLY VARIED BEDS
This paper presents a two-dimensional depth-averaged numerical model developed to simulate long-term sediment transport and morphological change in channels with gradually v aried beds. The model consists of three modules: the hydrodynamic module, the sediment transport module and the morphological module. Firstly, the hydrodynamic conditions are computed by solving the shallow-water equations with a depth-averaged k ε turbulence closure model. Based on the flow conditions, the suspended sediment concentration can be evaluated by solving the convection-diffusion equation while the bed load transport can be predicted from an empirical equation. Finally, the bed evolution can be calculated. In order to improve the computational efficiency, the authors propose an approximate method which is suitable for gradually varied flows. This method calculates the sediment transport and morphological evolution by assuming that the flow conditions are quasi-steady within the time step of sediment computation and thus the flow only needs to be calculated in the beginni ng of each sediment calculation. To examine the method’s validity and applicability, the model has been applied to a case of the trench evolution under the flow conditions. The numerical results are compared with the available experimental data. A good agreement has been obtained.
Quanhong Lin Pengzhi Lin
Department of Civil Engineering, National University of Singapore, 117576, Singapore State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University,610065, China
国际会议
第四届亚太地区海岸会议(the Fourth International Conference on Asian and Pacific Coasts)
南京
英文
2007-09-21(万方平台首次上网日期,不代表论文的发表时间)