Suppressing galloping-induced vibrations by integrating bluff body with surface protrusions

As a kind of self-excited large amplitude vibration, galloping is detrimental to engineering structures. Therefore, how to effectively suppress it has been a crucial issue for both industry and academia. In this Letter, a passive method based on integrating rectangular prismatic bluff bodies with different surface protrusions is proposed to mitigate galloping-induced vibrations. Both wind tunnel experiments and numerical simulations prove the validity of this method. Moreover, computational fluid dynamics simulations are also performed to investigate the underlying aerodynamic phenomena. Results reveal that the maximum amplitude and energy suppression ratios can reach 100%, especially for wind speeds higher than 3 m/s. As opposed to previous methods that delay galloping vibrations to higher wind speeds, this technique can directly change the vibration type from conjoint vortex-induced vibration (VIV)-galloping to VIV, which fundamentally eliminates galloping oscillations. Therefore, this method is promising in suppressing galloping vibrations.