Numerical modeling of flow around a pier mounted in a flat and fixed bed

Local scour around bridge piers is one of the main causes of bridge failures. Study of local scour is very significant for the safe design of piers and other civil and marine structures. Despite the subject has been explored for many decades, the numerical developments have been very limited due to the complicated interaction of three-dimensional flow, sediment transport and fluid-particle interaction. In this work, a numerical model based upon the Reynolds Average Navier Stokes Equation (k-epsilon) approach has been used for predicting the three dimensional flow (3D) around a bridge piers (square and cylinder piers), mounted on a flat and fixed bed. The main aim of this paper is the validation of the numerical model, based upon the previous experimental data. The CFD-numerical tool is proficient to qualitatively reproduce the flow characteristic for different pier shape and features around the pier, such as the upstream vortex (horseshoe vortex) and downstream vortex (vortex shedding in the wake). The outcome of this study can be used developing adequate numerical model to simulate the 2D and 3D turbulent flow past the square and circular piers, which are relevant case-studies for the marine and civil structures supported by pillars. The corresponding numerical results are in good agreement with those extracted from available experimental data. (C) 2019 The Authors. Published by Elsevier Ltd.