BEM ANALYSIS OF NONLINEAR FREE-SURFACE WAVES PROPAGATED BY A SUBMERGED OSCILLATING SHELL

In an attempt to investigate the behaviour of the free-surface waves generated by a forced oscillation of a submerged structural shell, a combined finite-boundary element method is used. The dynamic free-oscillation of the structure, discretized as an arch, due to self-weight and initial hydrostatic structure, discretized as an arch, due to self weight and initial hydrostatic loading is first determined using FEM. The same behaviour is used as its forced oscillation underwater. In the submerged state, the coordinates of the finite- element nodes are traced through a series of time steps. The flux is then computed as the velocity vector of water particles at the node normal to a boundary element. The boundaries, consisting of the enclosure's base, the arch, the opposite walls and the free-surface, are discretized as quadratic elements and analyzed using the boundary element method. The study is treated as a potential flow problem with the Laplace's equation serving as the governing equation. Non-linear equations on the free surface are derived and the geometric behaviour of the waves propagated by the forced oscillation of the arch is determined through an explicit time- integration scheme. Remeshing of the nodes at the arch-water interface and on the free surface id done for every time step and at 10 equal time increments covering one cycle of arch vibration.

• Supplemental Notes:
  • ISOPE 94, 4th Intl Offshore & Polar Engng Conf; 10-15 April 1994; Osaka, Japan. Sponsored by ISOPE, USA et al. Procs. Pubs by ISOPE, ISBN 1-880653-13-3. Vol III, p 99 [6 p, 10 ref, 5 fig]
• Authors:
  • Orejudos, J N
  • Ohkawa, H
  • Abe, K
• Publication Date: 1994

Language

• English

Subject/Index Terms

• TRT Terms: Boundary element method; Finite element method; Free surface; Oscillation; Underwater structures
• Subject Areas: Bridges and other structures; Marine Transportation;

Filing Info

• Accession Number: 00709379
• Record Type: Publication
• Source Agency: British Maritime Technology
• Files: TRIS
• Created Date: Aug 14 1995 12:00AM