Modelling of Flow-Induced Pulsations in Subsea Applications

Author(s):

G.S.Ravi Shankar , Dan Orfestor Engineering Solutions

Keywords:

Vortex induced vibration, Flow induced pulsation, Flexible risers, Marine structures

Abstract:

One of the classical problems in fluid mechanics is the determination of the flow field around a bluff body represented by a circular cylinder. This is of great interest in many engineering applications, such as hydrodynamic loading on ocean marine piles and offshore platform risers and casing pipes etc. The hydrodynamic behavior of the complex flow field around variety of circular cylinders shall be investigated. Wave induced vibration of structure such as marine pipelines, oil terminals, tanks and ships by placing oscillatory pressure on the surface of the structure. Flow-induced vibrations of slender marine structures can result from external or internal flows. VIV phenomenon is widely seen in subsea applications for risers, conductors, seabed pipelines and other subsea structures. FLIP occurs for rough bore flexible pipes, i.e. pipes with a corrugated metallic inner liner carcass is used for dry gas transport. As dry gas passes through a flexible riser, an unstable shear layer is generated off each of the internal corrugations which make up the internal carcass. Above a certain flow velocity vortices are shed from the carcass, at a frequency resulting in the generation and propagation of acoustic vibrations that lead to fatigue damage to topside and subsea small bore piping. The experimental work is carried to determine the dependence of the exact geometry i.e. corrugation geometry, length of the corrugated tube and the boundary conditions on the generation of pulsations. The obtained analytical tools will be validated by detailed CFD simulations and laboratory experimental tests.

Other Details:

Manuscript Id	:	IJSTEV6I11004
Published in	:	Volume : 6, Issue : 11
Publication Date	:	01/06/2020
Page(s)	:	1-5

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