Journal of Ocean Engineering and Technology (한국해양공학회지)

Korean Society of Ocean Engineers (한국해양공학회)
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Study on Optimal Damping Model of Very Large Offshore Semi-submersible Structure

초대형 반잠수식 해양 구조물의 최적 감쇠 모델에 대한 고찰

  • Lee, Hyebin (Multidisciplinary Graduate School Program for Wind Energy, Jeju National University) ;
  • Bae, Yoon Hyeok (Deptartment of Ocean System Engineering, Jeju National University) ;
  • Kim, Dongeun (Faculty of Wind Energy Engineering Graduate School, Jeju National University) ;
  • Park, Sewan (Korea Research Institute of Ships and Ocean Engineering) ;
  • Kim, Kyong-Hwan (Korea Research Institute of Ships and Ocean Engineering) ;
  • Hong, Keyyong (Korea Research Institute of Ships and Ocean Engineering)
  • 이혜빈 (제주대학교 풍력특성화협동과정) ;
  • 배윤혁 (제주대학교 해양시스템공학과) ;
  • 김동은 (제주대학교 풍력공학부) ;
  • 박세완 (선박해양플랜트연구소) ;
  • 김경환 (선박해양플랜트연구소) ;
  • 홍기용 (선박해양플랜트연구소)
  • Received : 2017.05.08
  • Accepted : 2018.01.25
  • Published : 2018.02.28
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Abstract

In order to analyze the response of the offshore structure numerically, the linear potential theory is generally applied for simplicity, and only the radiation damping is considered among various damping forces. Therefore, the results of a numerical simulation can be different from the motion of the structure in a real environment. To reduce the differences between the simulation results and experimental results, the viscous damping, which affects the motion of the structure, is also taken into account. The appropriate damping model is essential for the numerical simulation in order to obtain precise responses of the offshore structure. In this study, various damping models such as linear or quadratic damping and the nonlinear drag force from numerous slender bodies were used to simulate the free decay motion of the platform, and its characteristics were confirmed. The optimized damping model was found by comparing the simulation results to the experimental results. The hydrodynamic forces and wave exciting forces of the structure were obtained using WAMIT, and the free decay test was simulated using OrcaFlex. A free decay test of the scale model was performed by KRISO.

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References

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