Control of vortex shedding-induced effects in a sectional bridge model by spanwise perturbation method

An experimental study was conducted to determine the effectiveness of the spanwise sinusoidal perturbation method (SPPM) in controlling vortex-induced vibrations (VIV) in a plate girder bridge section model. The geometric parameters of the plate girder section model were selected to give the maximum VIV response. A SPPM module was attached to both the leading and trailing edges of the section model. Two different SPPM configurations with two different wavelengths and the same amplitude were utilized. Vertical motion responses, surface pressure measurements, as well as hotwire measurements in the wake of the section model were taken. The results revealed that the SPPM with the higher wave steepness distinctively suppressed the VIV responses.The behavior of the model with the SPPM is remarkably different with a fixed section model. Generally, a reduction in the fluctuating surface pressure components is observed, indicating an increase in the degree of steadiness of the flow around the model with either of the two SPPM configurations. However, no qualitative difference could be observed between the effects of the low and high wave steepness configurations. Moreover, wake measurements did not show any distinctive effect for either configuration when compared to the base case.