Experimental study on bird-wing-shaped suppression device for vortex-induced vibration of deep water risers

Based on the bionics study of trailing-edge serrations of certain birds, a vortex-induced vibration (VIV) suppression device for marine risers was developed, with double bird-wing-shaped streamers. A water flow simulation experiment was performed on a bare cylinder model as well as cylinder models with different trailing edge profiles and varying streamer lengths, and the model wake flow field was measured using particle image velocimetry. By comparing the corresponding wake streamline diagrams and vorticity, the following points were determined. The double streamer structure can reduce the velocity of the flow field on both sides of the cylinder in the water flow, and the vortex behind the cylinder. The trailing edge profiles of the streamers can affect the VIV, when using trailing-edge serrated streamers, the effect of making the vortex generation lag is more obvious. When the streamer length is approximately four times the cylinder diameter, the vortex suppression effect is improved. Therefore, the bird-wing-shaped VIV suppression device for risers can operate effectively.