Flutter stability studies of long span suspension bridge by CFD numerical simulation

This paper establishes two-dimensional bending and torsion fluid-structure interaction model to calculate flutter critical wind speed of the three-tower suspension bridge.There are three main girder schemes of the bridge.Scheme 1:Sharp fairing without central stabilizer;Scheme2:Sharp fairing with central stabilizer;Scheme 3:Semi-circular fairing without central stabilizer.Numerical calculation results indicate: At +3 degree wind attack angle, Flutter critical wind speed of scheme 1 is less than flutter checking wind speed; Flutter critical wind speed of scheme 2 is greater than flutter checking wind speed. Numerical simulation results is roughly consistent with the wind tunnel test. When the wind attack angle changes,the conventional sharp fairing is easy to lead large vortex formation that causing flutter stability declined.Large vortex formation can be inhibited by semi-circular fairing as scheme 3.It meets requirement of flutter stability without central stabilizer for the bridge.