Large eddy simulation of flow around semi-conical piers vertically mounted on the bed

• Published in: Environmental fluid mechanics (Dordrecht, Netherlands : 2001) Netherlands : 2001), 2022-10, Vol.22 (5), p.1211-1232
• Main Authors: Aghaee-Shalmani, Yasin, Hakimzadeh, Habib
• Format: Article
• Language: English
• Subjects: Bottom stress; Classical Mechanics; Conical flow; Cylinders; Earth and Environmental Science; Earth Sciences; Environmental Physics; Finite volume method; Flow simulation; Flow structures; Flow velocity; Fluid flow; Horseshoe vortices; Hydrogeology; Hydrology/Water Resources; Large eddy simulation; Large eddy simulations; Mathematical models; Navier-Stokes equations; Numerical models; Oceanography; Original Article; Piers; Reduction; Shear stress; Simulation; Slopes; Three dimensional flow; Three dimensional models; Upstream; Vortex shedding; Vortices
• ISSN: 1567-7419; 1573-1510
• DOI: 10.1007/s10652-022-09886-x

In this paper, details, and results of three-dimensional numerical modeling of flow around the semi-conical piers vertically mounted on the bed in a channel, are presented. For flow simulation, 3-D Navier–Stokes equations are solved numerically using the finite volume method and large eddy simulation. In this study, the semi-conical piers with different side slope angles ( α ) are tested, and the flow around them is compared with the cylindrical reference pier. Flow structures, vortex shedding behind piers, horseshoe vortices, instantaneous and time-averaged flow structures are presented and discussed. Numerical model results show that the semi-conical piers are eventuated remarkable reduction (up to 25%) in downward flow velocity in the upstream side of the piers, and much more reduction (up to 46%) in bed shear stresses in comparison with the cylindrical pier. Moreover, the model results showed some decrease in vortex shedding frequency for the semi-conical piers compared to the cylindrical pier. Article highlights We report on numerical results of large eddy simulation of the flow around semi-conical piers with different side slopes. This research is significant because of the effect of these piers on the: Reduction of the downward flow and the bed shear stress around the piers. Reduction of vortex shedding frequency for the semi-conical piers compared to the cylinder. Different behavior of the horseshoe vortices at the upstream compared to the cylinder.