A Finite Element Tool for Investigation of Vortex-Induced Vibration of Marine Risers
Vortex-induced vibration (VIV) is a major design issue for all deep-water riser systems
operating in regions where severe sea currents can be expected. This highly complex
phenomenon has resulted in a great deal of experimental work that today's empirical
models are based upon. These models are based on frequency domain dynamic solutions
and are therefore not directly applicable in a non-linear time domain model.
The purpose of the present work is to develop an approach to combine frequency domain
models with a time domain analysis software in order to predict VIV, and implement
this into a procedure named FEDEM-VIV. A force prediction algorithm is developed
to compute VIV response amplitudes with the Newmark time integration algorithm in
A validation study is carried out to compare the results from FEDEM-VIV with VIVANA
- a frequency domain code. Damping due to large amplitude is pragmatically
handled. Response shapes are for this reason not well captured, but maximum response
amplitudes are in some cases close to VIVANA estimates. High number of iterations
will in general over-estimate the response, and high amplitude damping is not predicted
well. Dening a lower limit of the excitation coecient for damping, with a low iteration
limit showed feasible predictions of the excitation force distribution. Excitation
zone predictions in VIVANA and FEDEM-VIV are in good agreement.
However, with the simplications in mind, the current approach represents a good solution
for a time domain VIV predictor when all the essential hydrodynamical eects are
accounted for in FEDEM-VIV.
Place, publisher, year, edition, pages
Institutt for produktutvikling og materialer , 2014. , 64 p.
IdentifiersURN: urn:nbn:no:ntnu:diva-26327Local ID: ntnudaim:10865OAI: oai:DiVA.org:ntnu-26327DiVA: diva2:746552
Haugen, Bjørn, FørsteamanuensisJakobsen, Ken-Robert G.