Two-Dimensional Numerical Simulation of Bed-Load Transport of a Finite-Depth Sediment Layer: Applications to Channel Flushing

Abstract

Numerical modeling of bed-load transport in shallow flows, particularly oriented toward environmental flows, is an active field of research. Nevertheless, other possible applications exist. In particular, bed-load transport phenomena are relevant in urban drainage systems, including sewers. However, few applications of coupled two-dimensional (2D) shallow-water and bed-load transport models can be found, and their transfer from environmental applications-usually river and floodplain-into sewer applications requires some adaptation. Unlike to river systems, where there is a thick layer of sediment that constitutes a movable riverbed, sewer systems have thin layers of sediment that need to be removed, thus exposing a rigid, nonerodible surface. This problem requires careful numerical treatment to avoid generating errors and instability in the simulation. This paper deals with a numerical approach to tackle this issue in an efficient way that allows large-scale studies to be performed and provides empirical evidence that the proposed approach is accurate and applicable for sewage and channelflushing problems.

Experimental Study on the Characteristics of Sediment Transport and Sorting in Pressurized Pipes

“…In the process of water-sediment movement, sediment particles move forward in the form of a bed load or suspended load due to the turbulence of water flow and the nonuniformity of sediment particles. While the fluid properties change due to the increase in fine sediment particles, its flow characteristics and sediment transport characteristics, including its flow state conversion characteristics [8,9], turbulence energy dissipation characteristics [10][11][12], sediment sorting characteristics [13][14][15][16], sedimentation patterns [17] and sediment transport and flushing [18], all change significantly. From the perspective of solid-liquid two-phase flow, some authors have established a two-phase flow model to explore the characteristics of water-sediment movement and analyze the distribution law of the sediment concentration profile [19].…”

Sediment transport prediction in sewer pipes during flushing operation

“…In the first approach, the one-dimensional Saint-Venant equations (Campisano et al 2006;Campisano and Modica, 2003;De Sutter et al 1999), coupled with the Exner equation for uniform (Campisano et al 2007(Campisano et al , 2004Creaco and Bertrand-Krajewski, 2009;Shirazi et al 2014) and non-uniform (Campisano et al 2019) sediments, are used for predicting bed sediment thickness changes during the flushing operation. More complex models involve the two-dimensional (Caviedes-Voullième et al 2017;Yu and Duan, 2014) and three-dimensional (Schaffner and Steinhardt, 2006) solutions of the Saint-Venant equations. An example of the literature models is as follows:…”

Numerical Assessment of Shear Boundary Layer Formation in Sewer Systems with Fluid-Sediment Phases

“…Understanding sedimentation in stormwater pipes is crucial for pipeline maintenance. In this regard, studies of sediment behavior in unpressurized sewer systems have been proposed [17][18][19][20]. Theoretical and analytical groundwork to support related research and design is urgently needed [21].…”