Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Numerical and Experimental Investigation of Hydrodynamic Interactions of Two VLFS Modules Deployed in Tandem

  • 4 Accesses


This paper numerically and experimentally investigates the hydrodynamic interaction between two semi-submersible type VLFS modules in the frequency domain. Model tests were conducted to investigate the relationship between interactions and wave headings. Numerical studies were performed by solving the radiation-diffraction problem and were validated against the experimental results. Motion Response Amplitude Operators (RAOs) were obtained from numerical and experimental studies. The dependency of the hydrodynamic interaction effect on wave headings is clarified. The influence of different wave periods on the motion responses of two-module VLFS and wave elevations in the gap is studied. The results indicate that the hydrodynamic interactions of the two modules are directly related to the wave headings and the periods of the incident wave. The shielding effect plays an important role in short wave, and the influence decreases with the increase of the incident wavelength. The numerical results based on the diffraction-radiation code can give a relatively good estimation to the responses in short wave while for long wave, it would over-predict the response.

This is a preview of subscription content, log in to check access.


  1. Bunnik, T., Pauw, W. and Voogt, A., 2009. Hydrodynamic analysis for side-by-side offloading, Proceedings of the 19th International Offshore and Polar Engineering Conference, ISOPE, Osaka, Japan, pp. 648–653.

  2. Chakrabarti, S., 2000. Hydrodynamic interaction forces on multi-moduled structures, Ocean Engineering, 27(10), 1037–1063.

  3. Chen, X.B., 2005. Hydrodynamic analysis for offshore LNG terminals, Proceedings of the 2nd International Workshop on Applied Offshore Hydrodynamics, Rio de Janeiro, Brazil, pp. 1–15.

  4. Cummins, W.E., 1962. The Impulse Response Function and Ship Motions, David Taylor Model Basin Washington DC.

  5. DNV, 2011. Sesam User Manual-Hydro D, Det Norske Veritas.

  6. Faltinsen, O.M., 1993. Sea Loads on Ships and Offshore Structures, Cambridge University Press, Cambridge.

  7. Hong, S.Y., Kim, J.H., Cho, S.K., Choi, Y.R. and Kim, Y.S., 2005. Numerical and experimental study on hydrodynamic interaction of side-by-side moored multiple vessels, Ocean Engineering, 32(7), 783–801.

  8. Huijsmans, R.H.M., Pinkster, J.A. and de Wilde, J.J., 2001. Diffraction and radiation of waves around side-by-side moored vessels, Proceedings of the 11th International Offshore and Polar Engineering Conference, ISOPE, Stavanger, Norway, pp. 406–413.

  9. Jean-Robert, F., Naciri, M. and Chen, X.B., 2006. Hydrodynamics of two side-by-side vessels experiments and numerical simulations, Proceedings of the 16th International Offshore and Polar Engineering Conference, ISOPE, San Francisco, USA, pp. 158–166.

  10. Kim, K.H., Kim, Y. and Kim, M.S., 2009. Numerical analysis on motion responses of adjacent multiple floating bodies by using rankine panel method, International Journal of Offshore and Polar Engineering, 19(2), 90–96.

  11. Lamas-Pardo, M., Iglesias, G. and Carral, L., 2015. A review of very large floating structures (VLFS) for coastal and offshore uses, Ocean Engineering, 109, 677–690.

  12. Lee, C., 1995. WAMIT Theory Manual, MIT Press, Cambridge, MA, USA.

  13. Lee, C.H. and Newman J.N., 2005. Computation of wave effects using the panel method, in: Chakrabarti, S.K. (ed.), Numerical Models in Fluid-Structure Interaction, WIT Press, Southampton, 42, 211–251.

  14. Lu, L., Cheng, L., Teng, B. and Sun, L., 2010. Numerical simulation and comparison of potential flow and viscous fluid models in near trapping of narrow gaps, Journal of Hydrodynamics, Ser. B, 22(5 Suppl 1), 120–125.

  15. Maniar, H.D., 1995. A Three Dimensional Higher Order Panel Method Based on B-Splines, Ph.D. Thesis, Department of Ocean Engineering, MIT, Cambridge, MA, USA.

  16. MARINTEK, 2009. SIMO Theory Manual, Sintef Trondheim.

  17. Newman, J.N., 1977. Marine Hydrodynamics, MIT Press, Cambridge, MA, USA.

  18. Ohkusu, M., 1976. Ship motions in vicinity of a structure, Proceedings of the 1st International Conference on the Behaviour of Offshore Structure, NIT, Trondheim, Norway, pp. 284–306.

  19. Riggs, R.H., Ertekin, C.R. and Mills, T.R.J., 2000. A comparative study of RMFC and FEA models for the wave-induced response of a MOB, Marine Structures, 13(4-5), 217–232.

  20. Suzuki, H., 2005. Overview of megafloat: Concept, design criteria, analysis, and design, Marine Structure, 18(2), 111–132.

  21. Van Oortmerssen, G., 1979. Hydrodynamic interaction between two structures floating in waves, Proceedings of the 2nd International Conference on Behavior of Offshore Structures, Hydromechanics Research Assn., London, UK, pp. 339–356.

  22. Wang, C.M. and Wang, B.T., 2015. Large Floating Structures: Technological Advances, Springer, Singapore.

  23. Wang, Y.T., Wang, X.F., Xu, S.W., Wang, L. and Li, J., 2018. Hydrodynamic interactions of a multi-modular semi-submersible type very large floating structure, Proceedings of the 28th International Ocean and Polar Engineering Conference, ISOPE, Sapporo, Japan, pp. 1137–1143.

  24. Watai, R.A., Dinoi, P., Ruggeri, F., Souto-Iglesias, A. and Simos, A.N., 2015. Rankine time-domain method with application to sideby-side gap flow modeling, Applied Ocean Research, 50, 69–90.

  25. Wu, L.J., Wang, Y.Z., Li, Y., Xiao, Z. and Li, Q.M., 2017a. Simplified algorithm for evaluating the hydrodynamic performance of very large modular semi-submersible structures, Ocean Engineering, 140, 105–124.

  26. Wu, Y.S., Ding, J., Li, Z.W., Ni, X.Y., Wu, X.F. and Tian, C., 2017b. Hydroelastic responses of VLFS deployed near islands and reefs, Proceedings of the ASME 201736th International Conference on Ocean, Offshore and Arctic Engineering, ASME, Trondheim, Norway, pp. V009T12A014.

  27. Wu, Y.S., Ding, J., Tian, C., Li, Z.W., Ling, H.J., Ma, X.Z. and Gao, J.L., 2018. Numerical analysis and model tests of a three-module VLFS deployed near islands and reefs, Journal of Ocean Engineering and Marine Energy, 4(2), 111–122.

  28. Xu, X., Li, X., Yang, J.M., and Xiao, L.F., 2016. Hydrodynamic interactions of three barges in close proximity in a floatover installation, China Ocean Engineering, 30(3), 343–358.

  29. Yoshida, K., Suzuki, H., Kato, S., Sumiyoshi, H. and Kado, M., 2001. A basic study for practical use of semisub-megafloat, Proceedings of the AMSE 20th International Conference on Offshore Mechanics and Arctic Engineering, AMSE, Rio de Janeiro, Brazil, pp. 3–8.

  30. Zhao, W.H., Yang, J.M., Hu, Z.Q. and Tao, L.B., 2014. Prediction of hydrodynamic performance of an FLNG system in side-by-side offloading operation, Journal of Fluids and Structures, 46, 89–110.

Download references


The authors would like to thank Mr. WANG Yongheng, JI Chuan-peng and ZHAO Liang for their efforts in model tests.

Author information

Correspondence to Sheng-wen Xu.

Additional information

Foundation item: The study was financially supported by the National Natural Science Foundation of China (Grant Nos. 51709170 and 51979167), the Ministry of Industry and Information Technology of China (Mooring position technology: floating support platform engineering (II)), the Shanghai Sailing Program (Grant No. 17YF1409700), and the China Scholarship Council (Grant No. 201806230206).

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Wang, Y., Wang, X., Xu, S. et al. Numerical and Experimental Investigation of Hydrodynamic Interactions of Two VLFS Modules Deployed in Tandem. China Ocean Eng 34, 46–55 (2020).

Download citation

Key words

  • hydrodynamic interaction
  • numerical analysis
  • model test
  • two semi-submersible type VLFS modules