Research on vortex-induced vibration control method based on flow field perturbation

Abstract

Based on the disturbance and energy dissipation effects of fans on the flow field, this paper proposes an innovative method for suppressing vortex-induced vibration (VIV) by installing fans on both sides of the bridge deck to reduce VIV responses. Firstly, in order to verify the effect of fan disturbance on the bridge deck structure and the surrounding flow field, we established a CFD (Computational Fluid Dynamics) numerical model with the cross-section dimensions of a long-span suspension bridge in Xiamen and conducted in-depth research on the impact mechanism of installing fans at the bridge deck on the incoming flow and the surrounding flow field of the bridge structure. Subsequently, based on the effect of the fan on the flow field and the bridge deck pressure, in order to further explore whether the method of adding fans to the bridge deck can be used as a VIV control measure, the suppression effect of the control method on the VIV response of the bridge is explored through section model wind tunnel tests and the specific effects of different fan numbers on the VIV response of the bridge were comparatively analyzed. The results from both numerical simulations and wind tunnel tests jointly indicate that when the wind passes over the bridge, the rotation of the fan blades can effectively disturb the surrounding flow field, thereby altering the wind pressure distribution and self-induced force on the bridge deck, and significantly reducing the vertical vibration response of the bridge. Furthermore, the research also found that a reasonable arrangement of fans can reduce the vertical displacement ratio of the section model by up to 97%.