Airfoil Vortex Induced Vibration suppression devices

Abstract

Vortex Induced Vibrations (VIV) is a major concern of the offshore oil industry. This problem leads to fatigue failure in the marine risers and causes costly replacement of the risers. Appendages such as helical strakes have proven that VIV can be eliminated but at the cost of increased drag. Increased drag reduces the time that the riser can operate. This thesis looks at adding airfoils to cylinders to both eliminate VIV as well as reducing drag. Two sets of tests were performed at the MIT Towing Tank to determine the effectiveness of these airfoils. The first tests utilized a flexible to model a riser. The second set of tests used a rigid cylinder to better understand the dynamics of the system. The airfoils were able to achieve both goals when the airfoils are aligned with the flow. Future work needs to be completed to study the airfoils when they are not aligned with the flow.