3D Layer-Integrated Modelling of Morphodynamic Processes Near River Regulated Structures

Abstract

Sedimentation and erosion can significantly affect the performance of river regulated reservoirs. In the vicinity of flow control structures, the interaction between the hydrodynamics and sediment transport often induces complex morphological processes. It is generally very challenging to accurately predict these morphological processes in real applications. Details are given of the refinement and application of a three-dimensional (3-D) layer integrated model to predict the morphological processes in a river regulated reservoir. The model employs an Alternating Direction Implicit finite difference algorithm to solve the mass, momentum and suspended sediment transport conservation equations, and an explicit finite difference scheme for the bed sediment mass conservation equation for calculating bed level changes. The model is verified against experimental data reported in the literature. It is then applied to a scaled physical model of a regulated reservoir, including the associated intakes and sluice gates, to predict the velocity distributions, sediment transport rates and bed level changes in the vicinity of the hydraulic structures. It is found that the velocity distribution near an intake is non-uniform, resulting in a reduction in the suspended sediment flux through the intake and the formation of a sedimentation zone inside the reservoir.

Two-Dimensional Numerical Simulation Study on Bed-Load Transport in the Fluctuating Backwater Area: A Case-Study Reservoir in China

“…Because of exiting of the source term, Equation (1) is a non-homogeneous partial differential equation. Consequently, Equations (12) and (13) are obtained after using the separation method within Equation 1:…”

“…In addition, a 3D computational fluid dynamics (CFD) model incorporating the Navier-Stokes equations using the k-epsilon turbulence closure and non-uniform sediment transport of Wu et al was used to simulate the bed-load changes in a section of the river Danube, and the results were most sensitive to the Shields number for the critical movement of the sediment [11]. The effects of various intake and sluice gate configurations, as well as their operational schemes, on the flow and sediment transport processes into reservoirs, were also investigated by a 3D model [12]. A finite-volume non-hydrostatic and shock-capturing 3D model for the simulation of wave-structure interaction and hydrodynamic phenomena (wave refraction, diffraction, shoaling, and breaking) was proposed by Gallerano and Cannata [13].…”

A Bibliometric Analysis and Review of Trends in Erosion and Sedimentation studies

“…Moreover, sedimentation in reservoirs causes huge storage loss and degrades the performance of damreservoir operations (Faghihirad et al, 2017). Improper land use and poor management of the ecosystem can also lead to land degradation and decreased storage capacity of reservoirs (Ayele et al, 2017).…”

Two-Dimensional Numerical Simulation Study on Bed-load Transport in Fluctuating Backwater Area: A Case-Study Reservoir in China

“…In addition, a 3D computational fluid dynamics (CFD) model with the Navier-Stokes equations using the k-epsilon turbulence closure and nonuniform sediment transport of Wu et al was used to simulate the bed-load changes in a section of the river Danube, and the results were most sensitive to the shields number for the critical movement of the sediments [11]. The effects of various intake and sluice gate configurations, as well as their operation schemes on the flow and sediment transport processes into reservoir were also investigated by a 3D model [12]. A finite-volume non-hydrostatic and shock-capturing 3D model for the simulation of wave-structure interaction and hydrodynamic phenomena (wave refraction, diffraction, shoaling and breaking) was proposed by Gallerano and Cannata [13].…”