Determination of flutter derivatives for a box-girder bridge deck through URANS simulations

In this paper the results of two-dimensional numerical simulations of the flow field around a box-girder bridge section of common geometry while it undergoes heaving or pitching harmonic oscillations are presented. Unsteady Reynolds-averaged Navier-Stokes equations are solved in conjunction with an eddy-viscosity and an explicit algebraic Reynolds stress model for turbulence modelling. The flutter derivatives at high Reynolds number for the bridge section considered are determined and compared with wind-tunnel results showing reasonable agreement. The key role played on the aeroelastic behavior of the profile by the degree of sharpness of the deck lower edges is highlighted. The influence on the self-excited forces of the amplitude of vibration is also investigated.