International Journal of Naval Architecture and Ocean Engineering

The Society of Naval Architects of Korea (대한조선학회)
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The effects of LNG-tank sloshing on the global motions of FLNG system

  • Hu, Zhi-Qiang (State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University) ;
  • Wang, Shu-Ya (State Key Laboratory of Ocean Engineering, Shanghai Jiao Tong University) ;
  • Chen, Gang (State Key Laboratory of Ocean Engineering, Shanghai Jiao Tong University) ;
  • Chai, Shu-Hong (University of Tasmania) ;
  • Jin, Yu-Ting (University of Tasmania)
  • Published : 2017.01.31
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Abstract

This paper addresses a study of inner-tank sloshing effect on motion responses of a Floating Liquefied Natural Gas (FLNG) system, through experimental analysis and numerical modeling. To investigate hydrodynamic characteristics of FLNG under the conditions of with and without LNG-tank sloshing, a series of numerical simulations were carried out using potential flow solver SESAM. To validate the numerical simulations, model tests on the FLNG system was conducted in both liquid and solid ballast conditions with 75% tank filling level in height. Good correlations were observed between the measured and predicted results, proving the feasibility of the numerical modeling technique. On the verified numerical model, Response Amplitude Operators (RAOs) of the FLNG with 25% and 50% tank filling levels were calculated in six degrees of freedom. The influence of tank sloshing with varying tank filling levels on the RAOs has been presented and analyzed. The results showed that LNG-tank sloshing has a noticeable impact on the roll motion response of the FLNG and a moderate tank filling level is less helpful in reducing the roll motion response.

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References

  1. Delorme, L., Iglesias, A.S., Perez, S.A., 2005. Sloshing loads simulation in LNG tankers with SPH. In: International Conference on Computational Methods in Marine Engineering, Barcelona.
  2. Faltinsen, O.M., Timokha, A.N., 2009. Sloshing. Cambridge University Press, New York.
  3. Kim, Y., 2001. Coupled analysis of ship motions and sloshing flows. In: 16th International Workshop on Water Waves and Floating Bodies, Hiroshima.
  4. Kim, Y., 2002. A numerical study on sloshing flows coupled with ship motion-the anti-rolling tank problem. J. Ship Res. 46, 52-62.
  5. Kim, Y., Nam, B., Kim, D., Kim, Y., 2007. Study on coupling effects of ship motion and sloshing. Ocean Eng. 34, 2176-2187. https://doi.org/10.1016/j.oceaneng.2007.03.008
  6. Lee, S.J., 2008. The Effects of LNG-sloshing on the Global Responses of LNG-carriers. Texas A&M University.
  7. Ludvigsen, A., PAN, Z.Y., Gou, P., Vada, T., 2013. Adapting a linear potential theory solver for the outer hull to account for fluid dynamics in tanks. In: Proceeding of the 32th OMAE 2013, Nantes, France.
  8. Malenica, S., Zalar, M., Chen, X., 2003. Dynamic coupling of seakeeping and sloshing. In: 13th International Offshore and Polar Engineering Conference, ISOPE, Honolulu, HI, pp. 25-30.
  9. Mitra, S., Wang, C., Reddy, J., Khoo, B., 2012. A 3D fully coupled analysis of nonlinear sloshing and ship motion. Ocean Eng. 39, 1-13. https://doi.org/10.1016/j.oceaneng.2011.09.015
  10. Molin, B., Remy, F., Rigaud, S., Jouette de, C., 2002. LNG FPSO's: frequency domain, coupled analysis of support and liquid cargo motion. In: Proceedings of the 10th International Maritime Association of the Mediterranean (IMAM) Conference, Rethymnon, Greece.
  11. Nam, B., Kim, Y., Kim, D., 2006. Nonlinear effects of sloshing flows on ship motion. In: International Workshop on Water Waves and Floating Bodies, Loughborough, UK.
  12. Nam, B.-W., Kim, Y., 2007. Effects of sloshing on the motion response of LNG-FPSO in waves. In: The 22nd Workshop on Water Waves and Floating Bodies, Plitvice, Croatia.
  13. Nasar, T., Sannasiraj, S., Sundar, V., 2008. Experimental study of liquid sloshing dynamics in a barge carrying tank. Fluid Dyn. Res. 40, 427-458. https://doi.org/10.1016/j.fluiddyn.2008.02.001
  14. Newman, J., 2005. Wave effects on vessels with internal tanks. In: Proceedings of the 20th Workshop on Water Waves and Floating Bodies, Spitsbergen, Norway.
  15. Register, Lloyd, 2009. Sloshing Assessment Guidance Document for Membrane Tank LNG Operations. LR Guidance Notes.
  16. Rognebakke, O.F., Faltinsen, O.M., 2003. Coupling of sloshing and ship motions. J. Ship Res. 47, 208-221.
  17. Veritas, Det Norske, 2006. Sloshing Analysis of LNG Membrane Tanks. DNV Classification Notes.
  18. Xie, Z.T., Yang, J.M., Hu, Z.Q., Zhao, W.H., Zhao, J.R., 2015. The horizontal stability of an FLNG with different turret locations. Int. J. Nav. Archit. Ocean Eng. 7, 244-258. https://doi.org/10.1515/ijnaoe-2015-0017
  19. Zhao, W.H., Yang, J.M., Hu, Z.Q., 2013a. Effects of sloshing on the global motion responses of FLNG. Ships Offshore Struct. 8, 111-122. https://doi.org/10.1080/17445302.2012.691272
  20. Zhao, W., Yang, J., Hu, Z.Q., Tao, L.B., 2014. Coupled analysis of nonlinear sloshing and ship motions. Appl. Ocean Res. 47, 85-97. https://doi.org/10.1016/j.apor.2014.04.001
  21. Zhao, W.H., Yang, J.M., Hu, Z.Q., Xiao, L.F., Peng, T., 2013b. Experimental and numerical investigation of the roll motion behavior of a floating liquefied natural gas system. Sci. China 56 (3), 629-644. https://doi.org/10.1007/s11431-012-5127-8
  22. Zhao, W.H., Yang, J.M., Hu, Z.Q., Xiao, L.F., 2012. Experimental investigation of effects of inner-tank sloshing on hydrodynamics of an FLNG system. J. Hydrodyn. Ser. B 24, 107-115. https://doi.org/10.1016/S1001-6058(11)60224-2

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