Numerical simulation of vortex-induced vibration of a 2D cylinder in oscillatory flow

Abstract

[Objectives] In the actual oil and gas exploitation,the combined actions of wind, waves and currents may cause the offshore platform to oscillate periodically,and then the relative oscillatory flow is generated between risers connected to the platform and the seawater. And there is significant difference in vortex shedding features existing between cylinders in oscillatory flow and in uniform flow.[Methods] The Vortex-induced Vibration(VIV) of 2D rigid cylinder periodic oscillating motion in still water is numerically simulated by using the CFD code naoe-FOAM-SJTU solver with overset function developed by OpenFOAM open source platform. Firstly, the grid convergence study is conducted for verification at KC=3. Then,the numerical simulation of 2D cylinder in oscillatory flow is conducted at KC=12.[Results] The comparisons of the results show that,the change of lift force coefficient increases under the effect of cross-flow vibration;the vortex trail direction and the position of the vortex separation points on the surface of the cylinder change significantly.[Conclusions] The research achievements in this paper can be used as the basis of VIV of a flexible riser in oscillatory flow using strip method.

Keywords

• oscillatory flow
• naoe-FOAM-SJTU solver
• Keulegan-Carpenter numbers
• Vortex-Induced Vibration (VIV)