An effective Euler-Lagrange model for suspended sediment transport by open channel flows

• Published in: International journal of sediment research Vol. 30; no. 4; pp. 361 - 370
• Main Authors: Shi, Huabin, Yu, Xiping
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2015; State Key Laboratory of Hydroscience and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing 100084, China
• Subjects: Eddy Interaction Model; Euler–Lagrange model; Open-channel flow; Sediment transport; Turbulence; 下线; 服务; 迁移; Open-channel flow; Turbulence; Euler–Lagrange model; Eddy Interaction Model; Sediment transport; Model Turbulence; Euler-Lagrange model; Eddy Interaction
• ISSN: 1001-6279
• DOI: 10.1016/j.ijsrc.2015.03.012

An Euler-Lagrange two-phase flow model is developed to study suspended sediment transport by open- channel flows with an Eddy Interaction Model （ELM） applied to consider the effect of fluid turbulence on sediment diffusion. For the continuous phase, the mean fluid velocity, the tui-bulent kinetic energy and its dissipation rate are directly estimated by well-established empirical formulas. For the dispersed phase, sediment particles are tracked by solving the equation of motion. The ElM is applied to compute the particle fluctuation velocity. Neglecting the effect of particles on flow turbulence as usually suggested for dilute cases in the literature, the Euler-Lagrange model is applied to simulate suspended sediment transport in open channels. Although the numerical results agree well with those by the well- known random walk particle tracking model （RWM） and with the laboratory data for fine sediment cases, it is clearly shown that such an Euler-Lagrange model underestimates the sediment concentration for the medium-sized and coarse sediment cases. To improve the model, a formula is proposed to consider the local fluid turbulence enhancement around a particle due to vortex shedding in the wake. Numerical results of the modified model then agree very well with laboratory data for not only the fine but also the coarse sediment cases.