Journal ArticleDOI
On the piston and sloshing modes in moonpools
Reads0
Chats0
TLDR
In this article, the authors considered rectangular moonpools of large horizontal dimensions and determined the natural modes of oscillation of the inner free surfaces under the assumption of infinite water depth and infinite length and beam of the barges that contain the moonpool.Abstract:
So-called ‘moonpools’ are vertical openings through the deck and hull of ships or barges, used for marine and offshore operations, such as pipe laying or recovery of divers. In the present study rectangular moonpools of large horizontal dimensions are considered. The natural modes of oscillation of the inner free surfaces are determined, under the assumption of infinite water depth and infinite length and beam of the barges that contain the moonpools. The problem is treated in two and three dimensions, via linearized potential flow theory. Results are given for the natural frequencies and the associated shapes of the free surface, for wide ranges of the geometric parameters. Simple quasi-analytical approximations are derived that yield the natural frequencies. The most striking result is that the natural frequencies of the longitudinal sloshing modes increase without bounds when both the draught and the width decrease to zero, the length of the moonpool being kept constant. As a corollary the problem of waves travelling in a channel through a rigid ice sheet is addressed and their dispersion equation is derived. The same behaviour is obtained: the waves travel increasingly faster as both the draught and the width of the channel are reduced.read more
Citations
More filters
Journal ArticleDOI
Coupled vessel and moonpool responses in regular and irregular waves
Senthuran Ravinthrakumar,Trygve Kristiansen,Bernard Molin,Bernard Molin,Babak Ommani,Babak Ommani +5 more
TL;DR: In this article, the authors investigated the hydrodynamic coupling between the ship and moonpool responses in the Ocean Basin at Sintef Ocean, where three different moonpool sizes are studied, where the moonpool length is 1/20, 1/10 and 1/2 of the ship length.
Journal ArticleDOI
An improved understanding of the natural resonances of moonpools contained within floating rigid-bodies: Theory and application to oscillating water column devices
TL;DR: In this paper, the fundamental interactions between waves, a floating rigid-body, and a moonpool that is selectively open to atmosphere or enclosed to purposefully induce pressure fluctuations are investigated, and an explicit hydrodynamic coupling term is included in the equations of motion.
Journal ArticleDOI
A two-dimensional numerical and experimental study of piston and sloshing resonance in moonpools with recess
TL;DR: In this article, a theoretical model based on linearized potential flow theory and eigenfunction expansion was developed to calculate the natural frequencies of two-dimensional moonpools with recess and two numerical methods were implemented: a boundary element method (BEM) and a Navier-Stokes solver (CFD).
References
More filters
Journal ArticleDOI
On the eigenvalue problem for fluid sloshing in a half-space
TL;DR: In this paper, the boundary value problem for free oscillations of a liquid in a half-space, which is bounded above by a rigid plane that contains a circular aperture, is transformed to a homogeneous, Fredholm integral equation for the velocity distribution in the aperture.
Journal ArticleDOI
Sloshing frequencies for a half-space with circular or strip-like aperture
TL;DR: In der vorliegenden Arbeit werden Naherungswerte (mit stengen Fehlerschranken) hergeleitet fur die Eigenfrequenzen der Schlingerbewegungen einer einen Halbraum with kreis- or streifenformiger Offnung aus fullenden idealen Flussigkeit as mentioned in this paper.
Journal ArticleDOI
A remark on the sloshing frequencies for a half-space
B. Andreas Troesch,R. Troesch +1 more
TL;DR: In this article, the known sloshing frequencies of an incompressible and inviscid fluid in a half-space with circular or strip-like aperture are investigated in some detail, based on previous results.
Journal ArticleDOI
Resonance interactions of waves in an ice channel
TL;DR: In this paper, it is shown that an ice channel is a waveguide for surface waves and the dispersive properties of the natural oscillations of the liquid in the channel are investigated.