0

Full Content is available to subscribers

Subscribe/Learn More  >

Calculation of Wave Forces and Internal Loads on a Semi-Submersible at Shallow Draft Using an iVOF Method

[+] Author Affiliations
Rogier de Bruijn, Fons Huijs

GustoMSC, Schiedam, The Netherlands

Tim Bunnik

Maritime Research Institute Netherlands, Wageningen, The Netherlands

René Huijsmans, Marc Gerritsma

Delft University of Technology, Delft, The Netherlands

Paper No. OMAE2011-49236, pp. 175-185; 11 pages
doi:10.1115/OMAE2011-49236
From:
  • ASME 2011 30th International Conference on Ocean, Offshore and Arctic Engineering
  • Volume 7: CFD and VIV; Offshore Geotechnics
  • Rotterdam, The Netherlands, June 19–24, 2011
  • ISBN: 978-0-7918-4439-7
  • Copyright © 2011 by ASME

abstract

When semi-submersibles are floating at shallow draft, only a relatively thin layer of water may be present above the floaters. Model tests and full scale observations have shown that in such cases, even in low waves, non-linear effects significantly influence the wave pattern around the floaters. These non-linear effects make conventional methods based on linear diffraction theory less reliable for the calculation of wave forces and internal loads on a semi-submersible at shallow draft. This paper describes and analyzes the non-linear hydrodynamics affecting the wave loads and internal loads at shallow draft. The feasibility of both ComFLOW and linear diffraction method for the calculation of these loads are assessed. CFD simulations were performed using ComFLOW, a program based on the incompressible Navier-Stokes equations and the improved Volume Of Fluid (iVOF) method. First, the wave loads acting on a fixed semi-submersible in regular waves were calculated with ComFLOW and compared with linear diffraction theory and model tests. Secondly, internal loads were calculated for a moving semi-submersible in regular waves using both ComFLOW and linear diffraction theory. In the ComFLOW simulations, the motions of the semi-submersible were prescribed instead of solved by the method itself. Calculations and comparisons were performed for deep draft and shallow draft conditions. The wave loads on the semi-submersible for shallow draft conditions derived with ComFLOW were reasonably close to the results from model testing, while the results from the linear diffraction method showed significant deviations from the model tests results. The internal loads calculated with ComFLOW were quite close to the results from the linear method, even for shallow draft conditions. Additional model testing is required for validation of the internal loads.

Copyright © 2011 by ASME

Figures

Tables

Interactive Graphics

Video

Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In