Ocean Systems Engineering

  • 제8권3호
  • /
  • Pages.329-343
  • /
  • 2018
  • /
  • 2093-6702(pISSN)
  • /
  • 2093-677X(eISSN)
테크노프레스 (Techno-Press)
권호 표지
DOI QR코드

DOI QR Code

Dynamic responses of an FPSO moored on sloped seabed under the action of environmental loads

  • Roy, Shovan (Department of Civil Engineering, National Institute of Technology Durgapur) ;
  • Banik, Atul K. (Department of Civil Engineering, National Institute of Technology Durgapur)
  • 투고 : 2018.05.04
  • 심사 : 2018.08.19
  • 발행 : 2018.09.25
⟨ 이전 논문 다음 논문 ⟩

초록

The inclination of seabed profile (sloped seabed) is one of the known topographic features which can be observed at different seabed level in the large offshore basin. A mooring system connected between the platform and global seabed is an integral part of the floating structure which tries to keep the floating platform settled in its own position against hostile sea environment. This paper deals with an investigation of the motion responses of an FPSO platform moored on the sloped seabed under the combined action of wave, wind and current loads. A three-dimensional panel discretization method has been used to model the floating body. To introduce the connection of multi-segmented non-linear elastic catenary mooring cables with the sloped seabed, a quasi-static composite catenary model is employed. The model and analysis have been completed by using hydrodynamic diffraction code AQWA. Validation of the numerical model has been successfully carried out with an experimental work published in the latest literature. The analysis procedure in this study has been followed time domain analysis. The study involves an objective oriented investigation on platform motions, in order to identify the effects of the slopped seabed, the action of the wave, wind and current loads and the presence of riser system. In the end, an effective analysis has been performed to identify a stable mooring model in demand of reducing structural responses of the FPSO.

키워드

과제정보

연구 과제 주관 기관 : National Institute of Technology, Durgapur

참고문헌

  1. Baar, J.J.M., Heyl, C.N. and Rodenbusch, G. (2000), "Extreme response of turret moored tankers", Proceedings of the 32nd Annual Offshore Technology Conference, Houston, Texas, May.
  2. Chai, Y.T., Varyani, K.S. and Barltrop, N.D.P. (2002), "Semi-analytical quasi-static formulation for three-dimensional partially grounded mooring system problems", Ocean Eng., 29, 627-649. https://doi.org/10.1016/S0029-8018(01)00038-5
  3. Faltinsen, O. (1990), Sea Loads on Ships and Offshore Structures, Cambridge University Press, Cambridge.
  4. Irani, M.B., Johnson R.P. and Ward E.G (2001), "FPSO responses to wind, wave and current loading", Proceedings of the 20th International Conference on Offshore Mechanics and Arctic Engineering, Rio de Janeiro, Brazil, January.
  5. Jones, D.O.B., Mrabure, C.O. and Gates, A.R. (2013), "Changes in deep-water epibenthic megafaunal assemblages in relation to seabed slope on the Nigerian margin", Deep Sea Research Part I: Oceanographic Research Papers, 78, 49-57. https://doi.org/10.1016/j.dsr.2013.04.005
  6. Kim, S.W., Kim, M.N. and Kang, H.Y. (2016), "Turret location impact on global performance of a thruster-assisted turret-moored FPSO", Ocean Syst. Eng., 6(3), 265-287. https://doi.org/10.12989/ose.2016.6.3.265
  7. Kim, M.H., Koo, B.J., Mercier, R.M. and Ward, E.G. (2005), "Vessel/mooring/riser coupled dynamic analysis of a turret-moored FPSO compared with OTRC experiment", Ocean Eng., 32, 1780-1802. https://doi.org/10.1016/j.oceaneng.2004.12.013
  8. Lee, D.H. (2002), "Nonlinear stability analysis and motion control of tandem moored tankers. Ph.D. Dissertation, Seoul National University, Seoul.
  9. Lopez, J. T., Taoa, L., Xiao, L. and Hu, Z. (2017), "Experimental study on the hydrodynamic behaviour of an FPSO in a deepwater region of the Gulf of Mexico", Ocean Eng., 129, 549-566. https://doi.org/10.1016/j.oceaneng.2016.10.036
  10. Ormberg, H. and Larsen, K. (1998), "Coupled analysis of floating motion and mooring dynamics for a turret-moored ship", J. Appl. Ocean Res., 20, 55-67. https://doi.org/10.1016/S0141-1187(98)00012-1
  11. Shivaji, G.T. and Sen, D. (2015), "Direct time domain analysis of floating structures with linear and nonlinear mooring stiffness in a 3D numerical wave tank", J. Appl. Ocean Res., 51, 153-170. https://doi.org/10.1016/j.apor.2015.04.002
  12. Sphaier, S.H., Fernandes, A.C. and Correa, S.H. (2000), "Maneuvering model for the FPSO horizontal plane behaviour", Proceedings of 10th International Offshore Polar Engineering Conference, Washington, USA, May-June.
  13. Tahar, A. and Kim, M.H. (2003), "Hull/mooring/riser coupled dynamic analysis and sensitivity study of a tanker-based FPSO", J. Appl. Ocean Res., 25 (6), 367-382. https://doi.org/10.1016/j.apor.2003.02.001
  14. Ward, E.G., Irani, M.B. and Johnson, R.P. (2001), "Responses of a tanker-based FPSO to hurricanes" Proceedings of the 33rd Offshore Technology Conference, Houston, Texas, April-May.
  15. Wichers, J.E.W. (1988), "A simulation model for a single point moored tanker", Ph.D. Dissertation, Delft University of Technology, Delft, Netherlands.