This Topic is support or building the fundamental knowledge to investigate and access the scour development and vibration around the offshore foundation and the others.
In fluid dynamics, vortex-induced vibrations (VIV) are motions induced on bodies interacting with an external fluid flow, produced by – or the motion producing – periodical irregularities on this flow.
They occur in many engineering situations, such as bridges, stacks, transmission lines, aircraft control surfaces, offshore structures, thermo-wells, engines, heat exchangers, marine cables, towed cables, drilling and production risers in petroleum production, mooring cables, moored structures, tethered structures, buoyancy and spar hulls, pipelines, cable-laying, members of jacketed structures, and other hydrodynamic and hydroacoustic applications. The most recent interest in long cylindrical members in water ensues from the development of hydrocarbon resources in depths of 1000 m or more.
Vortex-induced vibration (VIV) is an important source of fatigue damage to offshore oil exploration and production risers. (These slender structures experience both current flow and top-end vessel motions, which give rise to the flow-structure relative motion and cause VIV. The top-end vessel motion causes the riser to oscillate and the corresponding flow profile appears unsteady.)
VIV manifests itself on many different branches of engineering, from cables to heat Exchanger tube arrays. It is also a major consideration in the design of ocean structures. Thus the study of VIV is a part of a number of disciplines, incorporating fluid mechanics, structural mechanics, vibrations, computational fluid dynamics (CFD), acoustics, statistics, and smart materials.
How to Prevent VIV.
There are several ways to Apply the Vortex Shedding Prevention System. In Offshore Jacket they are using Rope to surround the substructure at a particular level (depend on Worse case VIV level study by engineering) as below: