Hydrodynamic Analysis of Two Coaxial Moonpool Floaters Using Theoretical Methodologies

Abstract

The present contribution aims at presenting a semi-analytical solution methodology of the linear hydrodynamic diffraction and radiation problems induced by two coaxial moonpool-type floaters subjected to incident waves. The flow field around the floaters is subdivided into ring-shaped fluid regions, in each of which axisymmetric eigenfunction-expansions of the velocity potential are made. The applied theoretical formulation is complemented by numerical-panel methodologies, using pulsating singularities distributed over the floaters’ wetted surface. Extensive numerical results in terms of exciting forces and hydrodynamic coefficients are given by applying frequency-domain techniques. The effect of the water trapped between the solids’ vertical walls on the floaters’ hydrodynamics is investigated and discussed. The presented analysis led to some remarkable trapping phenomena in the enclosed water areas, broadening the resonance-frequency bandwidth of the floaters when compared to a single moonpool body.

Hydrodynamics of an underwater vehicle near the sea surface

“…Once 𝑄 (𝜉, 𝜂, 𝜁) has been computed for each element the flow potential can be readily determined from Equation (30). The theoretical framework of this three-dimensional method is extensively described in Wehausen and Laitone (1960); Garrison (1974Garrison ( , 1975; Mavrakos and Bardis (1984), thus it is no further elaborated herein.…”