Author(s): Zhaoding Xie; Bushra Afzal; Tanju Sofu; Kornel Kerenyi; Junke Guo
Linked Author(s): Junke Guo
Keywords: LES FLUENT drag lift moment
Abstract: Highway bridges across rivers may be submerged during large floods, where the bridge deck may be turned over if the moment of hydrodynamic forces around the deck center is very large. Traditionally, these studies are physically modeled in hydraulics labs with expensive costs and laborious time. This study examines the applicability of CFD software, FLUENT 6.3, to estimate the drag and lift of an inundated bridge deck. The Large Eddy Simulation (LES) and the standard k-ε model were used to simulate the velocity and pressure fields around the bridge deck. The drag, lift and moment coefficients were then numerically calculated and compared with the flume measurements. The simulation results showed that: 1) For the drag coefficient, both LES and k-ε model produce reasonable results that are close to the experimental values; 2) for the lift coefficient, both simulations provide good results when bridge decks are totally submerged, whereas both simulations overestimate the lift coefficient for partially submerged decks; and 3) since the moment is a result of drag and lift, it is found that the moment coefficient agrees with experimental data for totally submerged decks while it is less than the experimental data for partially submerged decks. The velocity fields from LES simulation is very close to the Particle Image Velocimetry (PIV) measurements.