Matches in SemOpenAlex for { <https://semopenalex.org/work/W1968142872> ?p ?o ?g. }
Showing items 1 to 72 of
72
with 100 items per page.
- W1968142872 abstract "Abstract The objective of this paper is to present some model test results of vortex induced vibrations (VIV) of long marine risers subjected to shear current. Both a bare riser and a staggered buoyancy riser have been tested in vertical and inclined positions in a rotating rig. The vertical bare riser will be excited by one vortex shedding frequency in the uniform current, while the vertical staggered riser will experience two frequencies. For the sheared current cases (inclined riser) more then one vortex shedding frequency may be present along the riser for both configurations. The interaction between competing frequencies and modes are important items in the paper. The general trend is that the bare riser has transverse displacement spectra with mainly one peak frequency, even for the sheared current conditions. This is in contrast to the staggered riser test, where most spectra have at least two peaks. In some of the staggered riser tests it seems like the riser has locked in to both the vortex shedding frequency related to the riser diameter as well the vortex shedding frequency related to the buoyancy diameter. The relative effect of the buoyancy elements on the motions and the variation in peak frequencies is analyzed. Introduction The offshore oil and gas industry is gradually moving into deeper water and the marine riser is a critical component. A riser in deep water will experience the same wave induced loads as a riser in moderate water depth. but it will also experience current forces along a larger part of the length where there are no wave particle motions. Dynamic response due to vortices is important for these risers. It is well known that a flow around an elastic cylinder, such as a marine riser, will create vortices and induce vibrations. The frequency of the transverse load will normally be close to the Strouhal frequency, fs=St U I D. If the flow and/or the diameter vary along the riser, more than one excitation frequency may become active and the response will consist of more than one mode-shape. There are different theoretical models for describing the load and the response from vortices for long pipes in realistic current profiles. Today there is little knowledge of the interaction between frequencies and mode-shapes, and the models are related with large uncertainties. In order to increase the experience, two model tests have been conducted at MARINTEK. In the first model testl, 2, 3 (further denoted as the original test), VIV of a bare marine riser was studied for different shear profiles and speeds by use of a rotating rig. In the second model test, the rig was slightly modified, and both a bare riser and a staggered buoyancy riser were tested4. The results have been further analyzed in Ref. 5. The present paper will mainly present results from the second test. Key findings from the first test are listed in the following, The riser model had a low spatial attenuation resulting in a standing wave type of response pattern. Single frequency type response near the Strouhal frequency was observed even for strong shear. Several modes were present even if the response appeared at a single frequency." @default.
- W1968142872 created "2016-06-24" @default.
- W1968142872 creator A5009287751 @default.
- W1968142872 creator A5044598898 @default.
- W1968142872 creator A5071748474 @default.
- W1968142872 date "1998-05-04" @default.
- W1968142872 modified "2023-10-18" @default.
- W1968142872 title "VIV Model Test of a Bare- and a Staggered Buoyancy Riser in a Rotating Rig" @default.
- W1968142872 doi "https://doi.org/10.4043/8700-ms" @default.
- W1968142872 hasPublicationYear "1998" @default.
- W1968142872 type Work @default.
- W1968142872 sameAs 1968142872 @default.
- W1968142872 citedByCount "13" @default.
- W1968142872 countsByYear W19681428722015 @default.
- W1968142872 countsByYear W19681428722018 @default.
- W1968142872 countsByYear W19681428722019 @default.
- W1968142872 countsByYear W19681428722022 @default.
- W1968142872 crossrefType "proceedings-article" @default.
- W1968142872 hasAuthorship W1968142872A5009287751 @default.
- W1968142872 hasAuthorship W1968142872A5044598898 @default.
- W1968142872 hasAuthorship W1968142872A5071748474 @default.
- W1968142872 hasConcept C10599892 @default.
- W1968142872 hasConcept C111368507 @default.
- W1968142872 hasConcept C121332964 @default.
- W1968142872 hasConcept C127313418 @default.
- W1968142872 hasConcept C127413603 @default.
- W1968142872 hasConcept C140820882 @default.
- W1968142872 hasConcept C148043351 @default.
- W1968142872 hasConcept C171675602 @default.
- W1968142872 hasConcept C178760647 @default.
- W1968142872 hasConcept C182748727 @default.
- W1968142872 hasConcept C196558001 @default.
- W1968142872 hasConcept C198394728 @default.
- W1968142872 hasConcept C24890656 @default.
- W1968142872 hasConcept C25197100 @default.
- W1968142872 hasConcept C538625479 @default.
- W1968142872 hasConcept C57879066 @default.
- W1968142872 hasConcept C78519656 @default.
- W1968142872 hasConceptScore W1968142872C10599892 @default.
- W1968142872 hasConceptScore W1968142872C111368507 @default.
- W1968142872 hasConceptScore W1968142872C121332964 @default.
- W1968142872 hasConceptScore W1968142872C127313418 @default.
- W1968142872 hasConceptScore W1968142872C127413603 @default.
- W1968142872 hasConceptScore W1968142872C140820882 @default.
- W1968142872 hasConceptScore W1968142872C148043351 @default.
- W1968142872 hasConceptScore W1968142872C171675602 @default.
- W1968142872 hasConceptScore W1968142872C178760647 @default.
- W1968142872 hasConceptScore W1968142872C182748727 @default.
- W1968142872 hasConceptScore W1968142872C196558001 @default.
- W1968142872 hasConceptScore W1968142872C198394728 @default.
- W1968142872 hasConceptScore W1968142872C24890656 @default.
- W1968142872 hasConceptScore W1968142872C25197100 @default.
- W1968142872 hasConceptScore W1968142872C538625479 @default.
- W1968142872 hasConceptScore W1968142872C57879066 @default.
- W1968142872 hasConceptScore W1968142872C78519656 @default.
- W1968142872 hasLocation W19681428721 @default.
- W1968142872 hasOpenAccess W1968142872 @default.
- W1968142872 hasPrimaryLocation W19681428721 @default.
- W1968142872 hasRelatedWork W1891452224 @default.
- W1968142872 hasRelatedWork W1974186240 @default.
- W1968142872 hasRelatedWork W1988430121 @default.
- W1968142872 hasRelatedWork W2001718306 @default.
- W1968142872 hasRelatedWork W2061681527 @default.
- W1968142872 hasRelatedWork W2113631624 @default.
- W1968142872 hasRelatedWork W3023660763 @default.
- W1968142872 hasRelatedWork W3146835660 @default.
- W1968142872 hasRelatedWork W3193701420 @default.
- W1968142872 hasRelatedWork W603884760 @default.
- W1968142872 isParatext "false" @default.
- W1968142872 isRetracted "false" @default.
- W1968142872 magId "1968142872" @default.
- W1968142872 workType "article" @default.