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Numerical wind load estimation of offshore floating structures through sustainable maritime atmospheric boundary layer

  • Yeon, Seong Mo (Ship and Offshore Performance Research Center, Samsung Heavy Industries Co., Ltd) ;
  • Kim, Joo-Sung (Ship and Offshore Performance Research Center, Samsung Heavy Industries Co., Ltd) ;
  • Kim, Hyun Joe (Ship and Offshore Performance Research Center, Samsung Heavy Industries Co., Ltd)
  • Received : 2020.04.01
  • Accepted : 2020.07.05
  • Published : 2020.12.31

Abstract

Wind load is one of the major design loads for the hull and mooring of offshore floating structures, especially due to much larger windage area above water than under water. By virtue of extreme design philosophy, fully turbulent flow assumption can be justified and the hydrodynamic characteristics of the flow remain almost constant which implies the wind load is less sensitive to the Reynolds number around the design wind speed than wind profile. In the perspective of meteorology, wind profile used for wind load estimation is a part of Atmospheric Boundary Layer (ABL), especially maritime ABL (MBL) and have been studied how to implement the profile without losing turbulence properties numerically by several researchers. In this study, the MBL is implemented using an open source CFD toolkit, OpenFOAM and extended to unstable ABL as well as neutral ABL referred to as NPD profile. The homogeneity of the wind profile along wind direction is examined, especially with NPD profile. The NPD profile was applied to a semi-submersible rig and estimated wind load was compared with the results from wind tunnel test.

Keywords

References

  1. Andersen, O.J., Lovseth, J., 2006. The Froya database and maritime boundary layer wind description. Mar. Struct. 19, 173-192. https://doi.org/10.1016/j.marstruc.2006.07.003
  2. API, 2000. Recommended Practice for Planning, Designing and Constructing Fixed Offshore PlatformseWorking Stress Design. American Petroleum Institute.
  3. Blocken, B., Stathopoulos, T., Carmeliet, J., 2007. CFD Simulation of the Atmospheric Boundary Layer: Wall Function Problems. Atmospheric Environment.
  4. CAA, 2018. Cap 437 Standards for Offshore Helicopter Landing Areas.
  5. Cebeci, T., Bradshaw, P., 1977. Momentum Transfer in Boundary Layers, pp. 176-180.
  6. DNV, 2010. DNV-RP-C205: Environmental Conditions and Environmental Loads October 2010 - Recommended Practice. Dnv.
  7. Durbin, P.A., Reif, B.P., 2011. Statistical Theory and Modeling for Turbulent Flows, second ed. Wiley Sons Ltd.
  8. Hargreaves, D.M., Wright, N.G., 2007. On the use of the k-ε model in commercial CFD software to model the neutral atmospheric boundary layer. J. Wind Eng. Ind. 95, 355-369. https://doi.org/10.1016/j.jweia.2006.08.002
  9. Johnson, R., Gamma, E., Vlissides, J., Helm, R., 1995. Design Patterns: Elements of Reusable Object-Oriented Software. Addison-Wesley.
  10. Kim, J., Jang, H., Shen, Z., Yeon, S.M., 2019. Developing industry guidelines for the CFD-based evaluation of wind load on offshore floating facilities. In: Offshore Technology Conference, OTC-29270-MS, Houston, USA.
  11. Kim, J., Jang, H., Yeon, S., Kim, H., 2020. Numerical modeling of sustainable atmospheric and boundary layers for offshore floaters. In: 39th International Conference on Ocean. Offshore & Arctic Engineering, FL, USA, pp. 1-8.
  12. Kim, J.W., Jang, H., Xu, W., Shen, Z., Kara, M., Yeon, S., Yan, H., 2018. Numerical modeling of neutrally-stable and sustainable atmospheric boundary layer for the CFD simulation of wind load on offshore floating facilities. In: 37th International Conference on Ocean. Offshore and Arctic Engineering, Madrid, Spain.
  13. Molders, N., Kramm, G., 2014. Lectures in Meteorology. Springer.
  14. Richards, P., Hoxey, R., 1993. Appropriate boundary conditions for computational wind engineering models using the k-e turbulence model. J. Wind Eng. Ind. Aerod. 46, 145-153. https://doi.org/10.1016/0167-6105(93)90124-7
  15. Richards, P.J., Norris, S.E., 2011. Appropriate boundary conditions for computational wind engineering models revisited. J. Wind Eng. Ind. Aerod. 99, 257-266. https://doi.org/10.1016/j.jweia.2010.12.008
  16. Sumner, J., Masson, C., 2010. kE simulations of the neutral ABL: achieving horizontal homogeneity on practical grids. In: AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition, 48th.
  17. Vickery, P.J., 2014. Analysis of hurricane winds. In: Offshore Technology Conference. Offshore Technology Conference.
  18. Weller, H.G., Tabor, G., Jasak, H., Fureby, C., 1998. A tensorial approach to computational continuum mechanics using object-oriented techniques. Comput. Phys. 12 (6), 620-631. https://doi.org/10.1063/1.168744
  19. Yeon, S.M., Jang, H., Kim, J.W., Kim, J., Nam, B.W., Huang, Z., O'Sullivan, J., Kim, H.J., Hong, S.Y., 2019. Numerical modeling practice and verification of the wind load estimation for FPSO and semi-submersible. In: 38th International Conference on Ocean. Offshore & Arctic Engineering, Glasgow, Scottland, pp. 1-9.

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