MARINE RISER MODEL TESTS IN WAVES AND CURRENT

This paper presents the results of a research study investigating the combined loading due to ocean waves and shear currents on a single, flexible cylinder, representing a riser in 500m (1640ft) of water. The wave and current conditions used in the study reflect realistic environments used in offshore design. As part of the experimental study, an underwater video tracking technique is applied to directly measure the inline and transverse displacement fields of the riser. Standard instrumentation is also used to provide data on the cylinder tension and reaction forces. The accuracy of the underwater tracking methodology is evaluated as an alternative to strain gauge measurement, and the results are quite favourable. The combined wave and shear currents spectra are compared with the analytical model developed by Hung et al (1972). The experimental results compared well with the analytical model except at the very low and high frequencies. The inline riser displacements were compared to predicted response envelopes obtained using a two dimensional finite element model. The results of this simulation model, and choices for added mass and drag coefficients, are discussed. The riser simulations reproduced response envelope trends quite accurately for the conditions examined. The influence of two different current profiles combined to the same wave loading is also presented for both inline and transverse displacements. This illustrates the importance of current loading in the riser response behaviour.

  • Supplemental Notes:
    • OMAE 1995, 14th Intl Conf on Offshore Mechanics & Arctic Engng; 18-22 June 1995; Copenhagen, Denmark. Sponsored by ASME et al. Procs. Publ by ASME, ISBN 0-7918-1307-X. Vol I, Pt B, p 363 [11 p, 15 ref, 5 tab, 9 fig]
  • Authors:
    • Guerandel, V L
    • Niedzwecki, J M
    • Duggal, A S
  • Publication Date: 1995

Language

  • English

Subject/Index Terms

Filing Info

  • Accession Number: 00718521
  • Record Type: Publication
  • Source Agency: British Maritime Technology
  • Files: TRIS
  • Created Date: Mar 27 1996 12:00AM