Author(s): Ekkehard Holzbecher

Linked Author(s): Ekkehard Holzbecher

Keywords: Sediment transport; Shallow water equations; Multiphysics modelling; Scour

Abstract: Sediment transport in surface water bodies is a topic that is gaining increased relevance and scientific interest. With focus on sedimentation and re-suspension applied research is performed concerning rivers, channels, the coastal zone, reservoirs and floodwaters. Sediments are transported by water flow, and vice-versa sediments have an effect on flow, not only due to changes at the ground surface. That two-way coupling has to be taken into account when sediment transport is simulated in computer models. In this contribution a multiphysics approach of such a coupled model is presented. The shallow water equations (SWE) for water height and velocity are coupled with equations for particulate matter and bed-load. Using COMSOL Multiphysics software an implementation is presented that demonstrates the capability and feasibility of the model concept. The approach is applied to the problem of scouring and sedimentation at obstacles, which is particularly important for the stability of bridges across rivers and wadis. The study demonstrates that basic phenomena of sediment transport like scour creation and sediment deposition can be captured by the 2D coupled multiphysics approach. Further experimental and numerical research is needed to examine the its real capabilities and limits. In order to improve simulations with respect to field data, the proposed approach offers many options for the consideration of additional dependencies and processes.

DOI: https://doi.org/10.3850/IAHR-39WC252171192022163

Year: 2022