Author(s): Chunping Ren; Hanyue Liu
Linked Author(s):
Keywords: Submerged weir; Local scour; SedFOAM; Two-phase flow; Numerical simulation
Abstract: Submerged weirs in the river channel are important for enhancing the ecology of the river as they can create a shallow bank-deep channel bed pattern while preventing excessive undercutting of the riverbed and protecting the stability of the bank slopes. The existence of submerged weirs changes the overflow characteristics and induces local scour, and the downstream scour process has obvious two-phase flow characteristics of water and sand, and the hydrodynamic characteristics of the overflow and the local scour process of submerged weirs are still needed to be studied in depth by the submerged weir profiles. In this paper, a solid-liquid two-phase flow model of the downstream scouring process of the submerged weir was constructed based on SedFOAM, and the numerical model was verified by using the existing submerged weir local clear-water scouring test, meanwhile, the characteristics of the flow field around the weir, turbulence characteristics, and vortex characteristics were analyzed based on the results of the numerical model. On this basis, the influence of changes in the profile of the submerged weir (different upstream and downstream slopes of the weir, different water depths at the top of the weir, and different thicknesses of the weir) on the local scouring process was numerically investigated, and it was shown that the increase of upstream slope of the weir can effectively reduce the turbulence of the water around the top of the weir, thus reducing the scouring depth and silt accumulation after the weir, and the depth of water at the top of the weir has a larger influence on the scouring depth, whereas the weir canker thickness has a smaller influence on the scouring process, which is a very important factor for the protection of the riverbed, and for the protection of the riverbed. This study has theoretical and practical significance for the application of submerged weir in riverbed protection and river ecological restoration.
Year: 2024