Numerical Investigation of Flow Patterns Around Single and Twin Bridge Piers Using Turbulence Models in ANSYS Fluent

The flow pattern around a bridge pier is critical as it contributes directly to local scouring. Local scour around bridge piers is one of the primary causes of failure of bridges, as reported by various studies. ANSYS Fluent was utilized in this research to model and predict the three-dimensional flow field around five various types of piers placed on a rigid and flat bed. Both the twin-pier and single-pier configurations were examined because twin piers involve more complicated flow regimes than the single-pier configuration. Three different configurations for twin piers were tested: tandem (one behind the other), side-by-side, and inclined with respect to the flow direction at 0.8 Froude Number (subcritical flow). To simulate the turbulent behavior of the flow, various turbulence models were utilized, including the RANS (Reynolds-Averaged Navier-Stokes) SST k-omega and DES (Detached Eddy Simulation) models. Three-dimensional analysis was utilized by the study to obtain qualitative and quantitative information regarding flow characteristics, which provides more accurate hydrodynamics near piers than two-dimensional analysis. Important flow features such as velocity streamlines, turbulence kinetic energy contours, pressure distribution, and wall shear stress along the channel wall were observed. The parameters were strongly influenced by the pier geometry and pier spacing. Wall shear stress also changed along the channel length because of the piers. Since the flow velocity around piers directly affects the scouring patterns in the local vicinity, such intense analyses for different pier geometries are highly beneficial from an engineering perspective in Bangladesh, especially as new bridges are continually being designed to enhance transport networks.