WAVE FORCE ON A VESSEL TIED AT OFFSHORE DOLPHINS

[摘要] The solution of wave scattering by a vertical elliptical cylinder isapplied to calculate the wave forces exerted upon it. The wave forces inthe directions of long and short axes of ellipsis are shown in nondimensionalforms as the functions of the angle of wave approach, the diameter-to-wavelengthratio, and the aspect ratio of ellipsis. The results of wave force computedare also shown in terms of the virtual mass coefficients associated with thereference volume of the circular cylinder the diameter of which is approximatelyequal to the apparent width of the elliptical cylinder observed from the directionof wave approach.Theory is further applied for the wave forces acting upon a vessel mooredtight at offshore dolphins and the forces transmitted to the dolphins throughthe vessel. The vessel is approximated with the fixed elliptical cylinderhaving the same width-to-length ratio. The computation with directional wavespectra shows that a tanker of 200,000 D.W.T. may exert the force of about1,400 tons at the one-third maximum amplitude to each breasting dolphin whenthe tanker is exposed to the incident waves of H,/„=1.0m and T» / =10 sec fromthe broadside.

[学科分类] 建筑学

[关键词] wave forces;vessel;dolphin;offshore dolphin