Showing papers in "Ocean Engineering in 2000"

TL;DR: In this article, the hydrodynamic properties of a pair of long floating pontoon breakwaters of rectangular section are investigated theoretically, where the structures are partially restrained by linear symmetric moorings fore and aft.

TL;DR: In this article, the Navier-Stokes equations and the pressure Poisson equation for two-dimensional time-dependent viscous flows are solved with a finite difference method in a curvilinear coordinate system.

TL;DR: In this paper, a form of nonlinear equation governing the motion of a rolling ship subjected to synchronous beam waves is suggested and solved by the generalized Duffing's method in the frequency domain.

TL;DR: In this article, the interaction of water waves with arrays of bottom-mounted, surface-piercing circular cylinders is investigated theoretically under the assumptions of potential flow and linear wave theory, and a semi-analytical solution is obtained by an eigenfunction expansion approach.

TL;DR: In this article, the incompressible viscous shear flow past a circular cylinder is analyzed by solving two-dimensional Navier-Stokes equations and pressure Poisson equation using a finite difference method.

TL;DR: In this article, a wave-power system which combines the concept of a breakwater and a harbor resonance chamber was developed in order to protect the shoreline and extract energy from the ocean.

TL;DR: A test for nonstationarity based on the wavelet spectrum is described, which significantly diverge from those expected for a Gaussian random process, thus casting critical doubts on the conventional concept of the wind wave frequency spectrum.

TL;DR: In this article, the hydrodynamic properties of a long rigid floating pontoon interacting with linear oblique waves in water of finite arbitrary depth are examined theoretically, and the flow is idealized as linearized, velocity potentials are expressed in the form of eigen-function expansions with unknown coefficients.

TL;DR: In this paper, the interaction of water waves with a freely floating circular cylinder possessing a side-wall that is porous over a portion of its draft is investigated theoretically, where the porous side wall region is bounded top and bottom by impermeable end caps thereby resulting in an enclosed fluid region within the structure.

TL;DR: In this paper, a subjective safety-analysis-based decision-making framework is proposed for formal ship safety assessment in situations where a high level of uncertainty is involved, where failure events at the lowest level are modelled using fuzzy sets and safety synthesis at the different levels of a hierarchy is carried out using evidential reasoning.

TL;DR: In this article, the authors investigate the characteristics of parametric instability when very large variations of restoring between the wave trough and the wave crest are taking place, creating a restoring that is alternating between negative (or nearly negative) and strongly positive values.

TL;DR: The results in this paper indicate that the two-part underwater towed system improves the dynamic behavior of the towed vehicle and is an easy way to decouple the towing ship motion from the tow vehicle.

TL;DR: In this article, the interaction effect between the fully non-linear sloshing fluid and the floating tank associated with coupled surge, heave and pitch motions of the tank is analyzed for the first time in the present pilot study.

TL;DR: In this article, high-resolution motion and tension measurements were made of a caged deep-sea remotely operated vehicle (ROV) system with a ship A-frame and a tether.

TL;DR: In this paper, the wavelet transform is applied to the analysis of wave data measured in the nearshore areas of the Great Lakes, and the relatively unexplored wave grouping characteristics come to light as the predominant feature of wave processes.

TL;DR: In this paper, the long run distributions of several characteristics for the apparent waves in a Gaussian sea were discussed, including the instantaneous profile along a horizontal line, the encountered seaway, and the apparent periods, lengths, and heights.

TL;DR: In this article, the bifurcation behavior of an articulated loading platform subjected to harmonic excitation is investigated by the incremental harmonic balance (IHB) method, where the elements of the Jacobian matrix and the residue vector arising in the IHB formulations are derived in closed form.

TL;DR: In this article, a variety of potential probabilistic models for the meteorologically driven storm surge component of a long term water level observation record at Sandy Hook, New Jersey are assessed graphically in observation space for determining quality of fit in the upper tail of the data.

TL;DR: In this paper, the authors explored analytical methods for assessing the overall effect of structural design on the damage distributions in accidental grounding and collisions, and showed that the density distribution for collision and grounding damages normalized by the main dimensions of the ship depends on the size of a ship.

TL;DR: In this article, the damping coefficients for a single and double chamber absorbing-type caisson breakwaters are derived based on a single perforated-wall breakwater and a methodology is proposed to enable the estimation of damping coefficient for a breakwater with two chambers.

TL;DR: In this paper, the authors developed a continuous linear-elastic one-dimensional analytic model that should accurately represent a vertically tethered system subject to surface excitation, which can accurately predict: (a) the transfer function between the motion of the ship and cage, (b) the transferred function between ship motion and tension in the tether and (c) the natural frequency and its harmonics of the ROPOS deep-sea ROV system for depths between 0 and 1765 m up to moderately rough sea conditions.

TL;DR: In this article, a physical model study of combined refraction and diffraction of waves through a breakwater gap at different incident angles was conducted, where both regular and random waves with narrow and broad frequency and direction spreading were studied.

TL;DR: In this paper, the scale effect on the form factor of a ship's form factor was investigated using the ITTC'57 correlation line and the following equation K S − K M = 1.91·( λ − 1)·10 −3.

TL;DR: In this article, the problem of approximating the dynamics of a floating structure in a transient wave environment with a set of constant-coefficient differential equations is explored, assuming that the solutions of the corresponding steady-state time-harmonic radiation and diffraction problems are available.

TL;DR: In this paper, the weekly mean significant wave heights were derived from their monthly mean observations with the help of different alternative techniques including model-free neural network schemes as well as model-based statistical and numerical methods.

TL;DR: In this article, the authors describe a methodology for estimation of reliability of fixed offshore structures with respect to fatigue and extreme stress using fracture mechanics principle and API Code, and demonstrate application to a typical jacket platform.

TL;DR: In this paper, a complex eigen function method is used in the theoretical analysis of an offshore breakwater for which coefficients of both the wave reflection and transmission have low values, and the porosity of materials is varied in computations; and results are compared among structures composing of different layers of porous materials.

TL;DR: In this article, a finite-difference model in a curvilinear coordinate system was proposed to investigate the wave-induced seabed response in a porous seabing around a pipeline.

TL;DR: In this article, the problem of uniform applied loading at the outer boundary of a plate was solved using the Rayleigh-Ritz method and finite element algorithmic procedure, and good engineering agreement was shown.

TL;DR: The results predict that the moving-weight system can be an excellent roll-suppressing device when the moving weight is as small as 1% of the displacement of the ship and the maximum distance the weight moves is as Small–Amplitude–Motion Program, a computer code that integrates the governing equations of the sea and the motion of theShip interactively and simultaneously and predicts the motion in the time domain.