Experimental study on onset of Vortex-Induced Vibration of a pipeline near a seabed

Abstract

The critical flow velocity for onset of Vortex-Induced Vibration (VIV) of a pipeline near a rigid or a scoured seabed was experimentally investigated. The model pipe was initially positioned at a small gap to a rigid seabed or partially embedded in a silty seabed. The value of the embedment/gap-to-diameter ratio was changed from −0.2 to 1.0. A statistic form of the flow velocity, which is composed of the mean value and the Root-Mean-Square Deviation (RMSD) of the flow velocity, is applied in quantifying the onset condition of VIV. It was found that the onset of VIV is attributed to the joint contributions of both the mean flow and the turbulent component of the flow. The correlation of the critical reduced velocity with the initial position of the pipeline and the scour depth were concluded based on the experimental results.