Numerical Investigation for Aerodynamic Derivatives of Bridge Deck Using DES

Abstract

Detached Eddy Simulation（DES）is quite a new approach for the treatment of turbulence, which unites the efficiency of Reynolds Averaged Navier-Stokes Simulation (RANS) and the accuracy of Large Eddy Simulation (LES) into one framework. In this paper, DES method based on Spalart-Allmaras (S-A) turbulence model is employed to simulate the incompressible viscous flow around bridge decks. In order to obtain the aerodynamic forces, the forced motion simulations of the bridge decks are implemented by self-developed codes combined with FLUENT software. After obtaining the aerodynamic forces, aerodynamic derivatives are determined based on the least square algorithm. As the examples, the thin flat plate and the Great Belt East Bridge suspended spans cross-section are investigated to calculate their aerodynamic derivatives. Finally, the simulation results are compared to the data reported in other studies. The comparisons show that the present method gives much better prediction of the aerodynamic derivatives than RANS method and discrete vortex method (DVM).