Marine riser vortex induced vibration (VIV) suppression device

• Main Author: Muhamat Yain, Nursahliza
• Format: Thesis
• Language: English
• Published: 2017
• Subjects: TJ Mechanical engineering and machinery
• Online Access: http://eprints.utm.my/id/eprint/78945/1/NursahlizaMuhamatYainMFKM2017.pdf; http://eprints.utm.my/id/eprint/78945/; http://dms.library.utm.my:8080/vital/access/manager/Repository/vital:109826

Vortex-Induced Vibration (VIV) is a common phenomenon that occurred in the oil and gas industry and become one of the main concerns for the engineers while designing the riser system. Thus, this research represents the analysis of the vortex-induced motion of the circular cylindrical by using the Computational Fluid Dynamics (CFD) ANSYS CFX. The simulation was carried out in two-dimensional with the stationary condition. The bare cylinder was used as the reference for this research while the graph Strouhal number versus Reynolds number as the validation. The validation by using the Strouhal number is the common practice for the stationary circular cylinder simulation and Strouhal frequency obtained from this research was St ≈ 0.2. The simulation process was executed by using the ANSYS CFX Solver to simulate the cylinder and to identify the vortex shedding and also its magnitudes. The turbulent model used in this simulation is Detached Eddy Simulation and the vortices created at the back of the cylinder as well as the flow separation can be monitored through post-processor. Generally, when the fluid flow passed through the bluff body, it will excite by the forces and caused the vortices shed. These vortices will separate periodically asymmetrically from either side of the body caused the time varying non-uniform pressure distribution around it. This non-uniform pressure will create in both inline and transverse to the flow. By having the idea of parallel plates attached to the cylinder, it will help the flow separation become streamline as well as reduce the VIV on the marine riser. In addition, the Reynolds number is believed will give some significant effect on the behavior of VIV.