Hydrodynamic Behaviour of Floating Polygonal Platforms under Wave Action

Abstract

The hydrodynamic behaviour of floating regular polygonal platforms under wave action was studied by conducting parametric studies. Considering triangular, square, hexagonal, and circular platforms of similar size and draft, the results show that their added mass, radiation damping, and RAOs are similar. However, the wave exciting forces are slightly different, particularly the horizontal forces. The polygonal platforms oriented with one of its corners in line with the prevailing wave direction can lead to a reduction in the horizontal force on the platform, a feature that helps in reducing the cost of a mooring system. Moreover, such oriented platforms are able to disperse the waves better in multiple directions and hence will not pose problems for ships or marine vessels passing by the platform on the weather side. Thus, the orientation of a polygonal platform is an important design consideration. From the comparison study among different polygonal platforms, their wave attenuation performances are slightly similar. The hydrodynamic analyses performed herein for the parametric studies were sped up considerably by using a significantly lesser number of Fourier coefficient sets for the series functions that define the velocity potentials when compared to those used by previous researchers in their analytical approaches. The adoption of the radius function defined by cosine-type radial perturbation does not only generate the geometric boundaries of polygonal platforms, but it also simplifies the formulation and quickens the computations.

Hydrodynamic Behaviour of a Floating Polygonal Platform Centrally Placed within a Polygonal Ring Structure under Wave Action

“…In addition, as far as the wave exciting forces are concerned, the horizontal forces such as surge or sway forces are distinctively changed when polygonal shapes are appropriately used with their orientations. This phenomenon was already reported by Park and Wang [20]. Hence, in this parametric study, the free water surface elevation in the inner water basin will be the focus.…”

“…Liu, et al [24] replaced such radial terms with the Fourier expansion series so that the integration could be performed analytically. Recently, Park and Wang [20] suggested an improved method that enables the computational time to be significantly reduced by using minimal numbers of Fourier coefficient sets. By using Park and Wang [20] improved method, 13 sets of Fourier coefficients such as a…”

“…Recently, Park and Wang [20] suggested an improved method that enables the computational time to be significantly reduced by using minimal numbers of Fourier coefficient sets. By using Park and Wang [20] improved method, 13 sets of Fourier coefficients such as a…”

“…In practice, non-circular models are used for marine structure applications [17][18][19]. Recently, Park and Wang [20] and Park and Wang [21] respectively investigated the hydrodynamic behaviours of floating polygonal platforms and floating polygonal ring structures by solving the diffraction and radiation problems. The shape of the polygonal platform or ring structure was created by using the cosine-type radial perturbation [22].…”

Unlocking the Wave's Potential: Dynamic Numeric Simulation Response of Hexagon Buoy and Ring Heave Plate in a Shared Wave Environment

“…The research object consists of a hexagonal-shaped buoy as the floating component, a heave plate as the reaction control device, and a spar as the connecting element between them. Testing conducted by [12] has shown that a polygon-shaped buoy can effectively reduce wave excitation forces and pitching moments by orienting its corner sides towards the incoming waves. The buoy model to be used in this research is illustrated in Figure 1.…”