Sediment Transport under Flush Waves in Sewer Pipes

Maryam Alihosseini
Institute of Technology of Berlin, Germany
Fluid System Dynamics
Paul Uwe Thamsen

Despite numerous investigations, the complex process of sediment transport under flush waves, which are similar to a dam-break wave, is not yet well understood. The present work aims to calibrate and validate a coupled computational fluid dynamics and discrete element method (CFD-DEM) approach to study the fluid-sediment interaction in sewers. The CFD part of the simulation was carried out in the software ANSYS Fluent which is two-way coupled to the DEM software EDEM. The multiphase model volume of fluid (VOF) was used to simulate the flushing wave, while the sediments were handled as DEM particles using the discrete phase model (DPM). To validate the 3D model, experimental work has been performed in a circular laboratory pipe with sand and gravel of different size distributions. The results showed that the CFD-DEM method could be used to investigate the performance of flushing devices and various features of sediment transport which are not easy to obtain in the laboratory or field.

EDEM enhances the particle handling capability of the CFD software by resolving particle contacts and modelling non-spherical particles. The coupling of CFD and EDEM allowed modelling the complex process of sediment transport.

Maryam Alihosseini Institute of Technology of Berlin