Journal of Ocean Engineering and Technology (한국해양공학회지)

Korean Society of Ocean Engineers (한국해양공학회)
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Characteristics of Heaving Motion of Hollow Circular Cylinder

내부가 빈 원기둥의 수직운동 특성

  • Bae, Yoon Hyeok (Department of Civil Engineering, Texas A & M University) ;
  • Cho, Il-Hyoung (Department of Ocean System Engineering, Jeju National University)
  • 배윤혁 (텍사스A&M 대학교토목공학과) ;
  • 조일형 (제주대학교 해양시스템공학과)
  • Received : 2013.07.06
  • Accepted : 2013.10.10
  • Published : 2013.10.31
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Abstract

In the present investigation, the hydrodynamic characteristics of a vertically floating hollow cylinder in regular waves have been studied. The potential theory for solving the diffraction and radiation problem was employed by assuming that the heave response motion was linear. By using the matched eigenfunction expansion method, the characteristics of the exciting forces, hydrodynamic coefficients, and heave motion responses were investigated with various system parameters such as the radius and draft of a hollow cylinder. In the present analytical model, two resonances are identified: the system resonance of a hollow cylinder and the piston-mode resonance in the confined inner fluid region. The piston resonance mode is especially important in the motion response of a hollow circular cylinder. In many cases, the heave response at the piston resonance mode is large, and its resonant frequency can be predicted using the empirical formula of Fukuda (1977). The present design tool can be applied to analyze the motion response of a spar offshore structure with a moon pool.

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References

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