Showing papers in "Applied Ocean Research in 1995"

TL;DR: In this article, a wave energy device consisting of a thin vertical surface-piercing barrier next to a vertical wall in finite depth water is considered, and power is extracted due to a normally incident wave forcing the free surface of the fluid between the barrier and the wall to oscillate.

TL;DR: In this paper, a heaving cylinder with a vertical axis is modeled as a finite-order system of differential equations with constant coefficients, and good approximations are obtained when the order of the differential equation system is three for the radiation force and five for the excitation force.

TL;DR: In this paper, the authors investigated the non-causality of two impulse response functions, one of which relates the excitation force on an immersed body to the incident wave elevation at the body's reference position, while the other relates the event wave elevations at two different positions along the line of wave propagation, in spite of the fact wave propagation is a causal process.

TL;DR: In this paper, an eigenfunction expansion-matching method is extended to the analysis of the wave-induced responses of an elastic floating plate using modal expansions of the structural motion.

TL;DR: In this paper, a higher-order boundary element method was proposed for the calculation of the wave diffraction and radiation problem, and a higher order element discretisation of the resulting integral equation was used.

TL;DR: In this paper, a stochastic analysis procedure is developed to examine the properties of chaotic roll motion and the capsize of ships subjected to periodic excitation with a random noise disturbance.

TL;DR: In this paper, the diffraction/radiation boundary value problem arising from the interaction of oblique waves with freely floating long structures was studied using finite-element techniques, and the hydrodynamic behaviour of two-dimensional horizontal floating structures under the action of multi-directional waves was studied.

TL;DR: In this paper, the hydrodynamic parameters of a system of two concentric cylinders of the same radius were analyzed in a semi-submerged configuration, where one cylinder is semi-surmerged while the other is submerged and placed inside a tube with infinitesimal wall thickness.

TL;DR: In this article, a vertical circular cylinder submitted to both regular waves and moderate current in water of finite depth is considered, and the first-order and steady second-order forces are calculated.

TL;DR: In this paper, a new asymptotic method is applied to the analysis of roll decrement data which can determine nonlinear damping coefficients from large-amplitude roll motions.

TL;DR: In this article, it was shown that the slow drift force spectrum of a floating body, obtained from the exact quadratic transfer function, is flat in the low-frequency range of interest and can be written in the form SF( )=SF(0)+o( 2), where SF(0) can be computed from the known drift force coefficient in harmonic waves and the wave energy spectrum.

TL;DR: In this paper, a numerical solution for the transient motion of marine cables being towed from a cable ship which is changing speed is presented, where the cable ship is assumed to move rectilinearly, hence the cable configuration is two-dimensional.

TL;DR: In this article, the second order sum frequency wave generated by the interaction of first order irregular waves is discussed and an approximate method is presented for dividing a measured wave record into its first and second order components.

TL;DR: In this article, the problem of loss of stability of marine vehicles under cross-track error control in the presence of a mathematical model versus actual system mismatch is analyzed, and the response of the system after the initial loss of the stability of straight line motion is studied.

TL;DR: In this paper, a numerical model for the transient behavior of marine cables during laying operations is presented, which consists of dividing the cable into n straight elements with equilibrium relationships and geometric compatibility equations satisfied for each element.

TL;DR: In this article, a new approach for computing the Hilbert transform by constituting a moving average with two-sided or one-sided optimum coefficients which can be determined according to the statistical characteristics of the signal was proposed.

TL;DR: In this paper, the authors considered the radiation of water waves by a submerged, horizontal circular cylinder in a channel, where the cylinder axis is perpendicular to the channel walls and the length of the cylinder is less than the width of the channel.

TL;DR: In this article, a study of the diffraction of periodic nonlinear shallow water waves around a vertical cylinder is presented, where the generalized Boussinesq (GB) numerical model is used to effectively simulate the propagation of cnoidal waves and the associated three-dimensional nonlinear interactions.

TL;DR: In this article, the hydrodynamic problem associated with water wave radiation and diffraction by a group of submerged spheres is analyzed based on the linearized velocity potential, where no restriction on the submergences and radii of the spheres, or the distances between spheres.

TL;DR: In this paper, a procedure has been developed to determine the probability of a ship encountering a severe storm, in terms of the return period of the storm as well as the operation profile of the ship and the wave statistics along its route.

TL;DR: In this paper, the loss of stability at moderate-to-high speeds is examined using a nonlinear Hopf bifurcation analysis, which is used for demonstration purposes for depth control at level attitude and for a fixed nominal speed.

TL;DR: In this article, the time-dependent, attached, oscillatory, turbulent boundary-layer flow over a smooth circular cylinder is modelled and reduced to the solution of a number of analogous flat-plate problems, a technique that is applicable if the fluid particle amplitude is small compared with the diameter of the cylinder.

TL;DR: In this paper, the authors describe one such model test of a gravity-based offshore structure, which is unique and required model testing to generate confidence in the method of launching, and a necessary solution is discussed.

TL;DR: In this article, the dual-reciprocity boundary-element method was further applied to the case of short waves with short wavelengths, and the model's excellent accuracy and efficiency in modelling short waves was further established after some of the preliminary results are compared with corresponding previously published numerical and experimental data.

TL;DR: In this article, the problem of interface wave diffraction by a thin vertical barrier which is completely submerged in the lower fluid of two superposed infinite fluids and which extends infinitely downwards into the upper fluid was formulated in terms of a hypersingular integral equation for the difference of potential across the barrier.

TL;DR: For a general symmetric spread Mooring system (SMS), the necessary and sufficient conditions for stability are derived analytically as discussed by the authors, and it is shown that only two conditions are dominant in symmetric ship moorings.

TL;DR: In this article, numerical techniques have been developed to filter and differentiate laboratory velocity data collected under irregular waves in order to compute estimates of the local fluid accelerations, and algorithms for evaluating several acceleration theories are furthermore presented.

TL;DR: In this paper, the slow drift motion of a floating body in a two-dimensional wave field was investigated using a time-domain, fully nonlinear numerical model with nonreflective open boundaries.

TL;DR: In this article, the interaction between a uniform current and an oscillating, submerged circular cylinder is solved using a quasi-linear model based on Dagan and Miloh's single source solution.