ABSTRACT
The study of the flow field around cylinders has benefited from numerical simulations as step beyond potential flow approximations. In recent times, large eddy simulations (LES) were used to predict the flow field, bed evolution and sediment entrainment mechanisms around piers (Tseng et al. 2000, Roulund et al. 2005, Kirkil et al. 2008). The purpose of this paper is to analyze the effect of the suspended sediment load on the flow field around a cylinder by performing numerical simulations. A numerical code which includes a suspended sediment transport module is used. The code is an Euler-Euler single-phase approach involving LES with sub-gridscale model to solve the 3D Navier-Stokes equations and an advection-diffusion equation for suspended sediment transport (Dallali & Armenio 2014). In this work, numerical results with and without suspended sediment are compared in terms of mean velocity, vorticity, components of Reynold stress tensor and Strouhal number. The numerical results for the clear water case are also compared with existing experimental data to analyze the flow field downstream the cylinder (Ricardo et al. 2014a, Ricardo et al. 2014b). Results show that a Von Karman street flow pattern is still identifiable. Small differences in first and second-order moments of velocity fluctuations are identified and discussed.
