عنوان مقاله [English]
In this paper, the 3-D flow pattern around the pier with different sections is simulated using Fluent software. The pier sections modeled in this study included circular, spindle, oval, rectangular, square, and combined (rectangle - circle) sections. The software solves the flow equations using finite volume and pattern of cell centralism. Prismatic networks were used for computational lattice field. These networks were produced using the pre-processor Gambit. The computational field was then analyzed using the Fluent software. The Fluid Volume Method (VOF) is used to involve the free surface in three-dimensional modeling. Flow turbulence has been entered in the calculations using k – e model. In three-dimensional models, the effect of changes in water surface profiles and piers shape were investigated on decreasing shear stress and thus reducing scouring. The results indicated that spindle and elliptical cross sections have the largest effect in reducing shear stress and thus scouring around piers. The low velocity flow is formed around these piers and no large disturbance and no return flow, as important factors in scouring, are observed for spindle shaped piers.