Abstract
A computational study is conducted to investigate the effect of side-by-side arrangement of cylindrical piers on river bed morphodynamics and the local scour holes. This phenomenon is simulated by a sophisticated 3D model in which the flow is simulated by large-eddy simulation and the sediment is simulated in a Lagrangian framework as rigid spheres transported by the water. The bed morphodynamics is the result of pick-up and deposition of the solitary sediment particles. Through comparison for scour of a single cylinder with experimental data, the model shows a reasonable agreement of scour patterns and evolution of local scouring. For the side-by-side arrangement of cylinders, the bed scouring at the nose of both cylinders is mostly identical and the bed morphological changes are nearly symmetric along the center plane in streamwise direction. Maximum scour depth exhibits a growing trend with decrease in distance of cylinders, which agrees well with the experimental data from previously published literature.
