The Numerical Modeling of Ship Motions and Capsizing in Severe Seas

Abstract

A numerical model has been developed to determine the large-amplitude motions of a steered vessel subjected to severe wave conditions, including those that may lead to capsizing. The model was used to identify different modes of capsizing, and to study relevant mechanisms and conditions. In this paper emphasis is placed on the theoretical aspects. The nonlinear model combines both potential and viscous flow effects, where integrations are carried out in the time domain over the instantaneous free surface; first-order memory effects are taken into account, and the free surface can be irregular, Some new results are presented concerning statistical properties relevant to the simulation of random following or quartering seas.

Sensitivity Analysis of the Turning Motion of an Underwater Glider on the Viscous Hydrodynamic Coefficients

“…A study on the sensitivity of maneuvering characteristics on hydrodynamic coefficients was undertaken for ships by Debabrata Sen 16 . The definition of sensitivity index used in this study is analogous to a similar index defined by De Kat and Paulling 17 . The methodology used involves characterising R which signifies some measure of the maneuvering performance of the vehicle.…”

Co-simulation of ship motions and sloshing in tanks

“…Similarly, ship motions cannot be addressed through a linear approach whenever the interest is on the simulation of the behaviour of a vessel which is free running in wind and waves (e.g. Bulian et al, 2015;de Kat and Paulling, 1989;Matusiak, 2007). In all such cases, it is necessary to describe the dynamics of the vessel by means of nonlinear models.…”

Simulation based calculation of ship motions in extreme seas with a body-exact strip theory approach

“…In this paper, it is aimed to use a similar approach to the non-linear strip theory extensions, which are faster than the 3D solution. In this context, as cited in STANAG 4154 [1], studies carried out by Kaplan and Sargent [5], Mansour and d'Oliveira [6] (The computer program ADMASS for the frequency-dependent added mass calculation), Meyerhoff and Schlachter [7], Schlachter [8]& [9] (The computer program DYNBEL) and Guedes Soares [10] on the vertical plane; studies carried out by De Kat [11]& [12] and De Kat and Paulling [13] on the six degrees of freedom are first coming to the forefront. In these approaches, as in the case of the 3D methods, the search for a solution is made "over the instantaneous wetted hull surface".…”

“…In these approaches, as in the case of the 3D methods, the search for a solution is made "over the instantaneous wetted hull surface". De Kat and Paulling [13] described this solution search as a "geometric" nonlinearity. The solution of the equations of motion in the time domain may require the use of convolution integrals that take into account the memory effects.…”

“…The solution of the equations of motion in the time domain may require the use of convolution integrals that take into account the memory effects. An example to this approach, in which the nonlinear effects in large amplitude motions are taken into account and the strip theory is used in the time domain with the convolution integrals, is the stud-ies of Fonseca and Guedes Soares [12] [14]& [15]. In these studies the hydrostatic/Froude-Krylov forces are solved over the instantaneous wetted hull surface.…”