Journal of Ocean Engineering and Technology (한국해양공학회지)

Korean Society of Ocean Engineers (한국해양공학회)
권호 표지
DOI QR코드

DOI QR Code

An Experimental Study of Wave Impact Loads on an FPSO Bow in 2D Wave-Tank

  • Dong-Min Park (Korea Research Institute of Ships & Ocean Engineering) ;
  • Byoungjae Park (Korea Research Institute of Ships & Ocean Engineering) ;
  • Kangsu Lee (Korea Research Institute of Ships & Ocean Engineering)
  • Received : 2024.06.03
  • Accepted : 2024.09.03
  • Published : 2024.10.31
Download PDF
⟨ Previous Next ⟩

Abstract

In harsh environments, an floating production storage and offloading (FPSO) is occasionally damaged by impact loads, such as bow flare slamming and green water. This study conducted an impact load measurement experiment on a model of an FPSO bow in a 2D wave tank. Three types of frequency-focused waves (steep, spilling, and plunging) were generated, and the speed and slope of the waves were measured. Seven wave probes were placed in a row, and the wave elevation was measured to determine the speed and slope of the waves. In addition, the side of the 2D wave tank was photographed with a high-speed camera. The speed and slope of the waves obtained from the wave probe array agreed well with those obtained from the photographs taken using a high-speed camera. In the case of a steep wave, wave runup occurred at the bow before the wave reached the bow of the FPSO, so no impact load was generated, and only hydrostatic pressure was measured. Impact loads were generated in the spilling and plunging waves, and the magnitude of impact loads using the Von Karman's estimation formula and the impact loads measured in model tests showed similar values.

Keywords

Acknowledgement

This research was supported by a grant from the Endowment Project of "Core Technology Development of Hydro-elasticity based Structural Damage Assessment for Offshore Structures considering Uncertainty (5/5)", funded by the Korea Research Institute of Ships and Ocean Engineering (PES5150).

References

  1. Bredmose, H., & Jacobsen, N. G. (2010, January). Breaking wave impacts on offshore wind turbine foundations: focused wave groups and CFD. In International Conference on Offshore Mechanics and Arctic Engineering (Vol. 49118, pp. 397-404).
  2. Buchner, B., Hodgson, T., Voogt, A. J., Ballard, E., Barltrop, N., Falkenberg, E., Fyfe, S., Guedes Soares, C., Iwanowski, B., & Kleefsman, T. (2004). Summary report on design guidance and assessment methodologies for wave slam and green water impact loading. MARIN (Report No. 15874-1-OE). Wageningen, The Netherlands.
  3. Det Norske Veritas. (2017). Horizontal wave impact loads for column stabilized units (DNVGL-OTG-14). Det Norske Veritas.
  4. Ha, Y. J., Kim, K. H., Nam, B. W., & Hong, S. Y. (2020). Experimental investigation for characteristics of wave impact loads on a vertical cylinder in breaking waves. Ocean Engineering, 209, 107470. https://doi.org/10.1016/j.oceaneng.2020.107470
  5. Ha, Y. J., Nam, B. W., Kim, K. H., & Hong, S. Y. (2024). Numerical study for slamming loads on the bow of a ship-type FPSO model under breaking waves. Ocean Engineering, 299, 117404. https://doi.org/10.1016/j.oceaneng.2024.117404
  6. Hong, S. K., Lew, J. M., Jung, D. W., Kim, H. T., Lee, D. Y., & Seo, J. S. (2017). A study on the impact load acting on an FPSO bow by steep waves. International Journal of Naval Architecture and Ocean Engineering, 9(1), 1-10. https://doi.org/10.1016/j.ijnaoe.2016.06.006
  7. Hu, Z. Z., Mai, T., Greaves, D., & Raby, A. (2017). Investigations of offshore breaking wave impacts on a large offshore structure. Journal of Fluids and Structures, 75, 99-116. https://doi.org/10.1016/j.jfluidstructs.2017.08.005
  8. Kamath, A., Chella, M. A., Bihs, H., & Arntsen, O. A. (2016). Breaking wave interaction with a vertical cylinder and the effect of breaker location. Ocean Engineering, 128, 105-115. https://doi.org/10.1016/j.oceaneng.2016.10.025
  9. Kim, K. H., Lee, D. Y., Hong, S. Y., Kim, B. W., Kim, Y. S., & Nam, B. W. (2014). Experimental study on the water impact load on symmetric and asymmetric wedges [Conference presentation]. 24th ISOPE International Ocean and Polar Engineering Conferenc, Busan, Korea.
  10. Kim, U. N. (2015). Bow structure design of the FPSO installed in the North Sea under the flare slamming load. Journal of the Society of Naval Architects of Korea, 52(5), 418-424. https://doi.org/10.3744/SNAK.2015.52.5.418
  11. Nam, H. S., Park, D. M., Cho, S. K., & Hong, S. Y. (2022). Analysis of relative wave elevation around semi-submersible platform through model test: focusing on comparison of wave probe characteristics. Journal of Ocean Engineering and Technology, 36(1), 1-10. https://doi.org/10.26748/KSOE.2021.094
  12. Park, D. M., Kwon, Y. J., Nam, H. S., Nam, B. W., & Lee, K. (2022). An experimental study of wave impact pressure on an FPSO bow under head sea conditions. Ocean Engineering, 249, 110993. https://doi.org/10.1016/j.oceaneng.2022.110993
  13. Soares, C. G., Pascoal, R., Antao, E. M., Voogt, A. J., & Buchner, B. (2007). An approach to calculate the probability of wave impact on an FPSO bow. Journal of Offshore Mechanics and Arctic Engineering, 129(2), 73-80. https://doi.org/10.1115/1.2426983
  14. Stansberg, C. T. (2008). A wave impact parameter. Proceedings of the 27th International Conference on Offshore Mechanics and Arctic Engineering (pp. 301-308). https://doi.org/10.1115/OMAE 2008-57801
  15. Von Karman, T. H. (1929). The impact on seaplane floats during landing (No. NACA-TN-321).
  16. Voogt, A., & Buchner, B. (2004). Prediction of wave impact loads on ship-type offshore structures in steep fronted waves [Conference presentation]. 14th International Offshore and Polar Engineering Conference, Toulon, France.
  17. Xu, L., & Barltrop, N. (2005). Wave slap loading on FPSO bows: research report 324.
  18. Xu, L., Barltrop, N., & Okan, B. (2008). Bow impact loading on FPSOs 1-Experimental investigation. Ocean Engineering, 35(11-12), 1148-1157. https://doi.org/10.1016/j.oceaneng.2008.04.013