Author(s): Penghua Teng; J. Gunnar I. Hellstrom; Dan Nilsson

Linked Author(s): Gunnar Hellström

Keywords: Immobile boulders; CFD-DEM; Bed roughness; Turbulent flow

Abstract: Large boulders on a roughness streambed can influence local flow fields, turbulent structures, sediment transport rates, and aquatic habitats. In this paper, based on a previously conducted physical experiment, a resolved Computational Fluid Dynamics (CFD) -Discrete Element Method (DEM) approach is employed to represent turbulence flow over a submerged boulder in a rough surface channel. Simulation results illustrate flow dynamics over the boulder. The flow velocity profiles in numerical results show a good agreement with the experimental data. The results show that the presence of the boulder alters the flow field in their vicinity. Additionally, by comparing simulations of a boulder in both rough and smooth channel conditions, surface roughness influences the near-bed flow velocity and local turbulence around the submerged boulder.

DOI: https://doi.org/10.3850/iahr-hic2483430201-91

Year: 2024