Showing papers in "Ocean Engineering in 1993"

TL;DR: Boussinesq type equations with improved linear dispersion characteristics are derived and applied to study wave-wave interaction in shallow water in this article, where weakly nonlinear solutions are formulated in terms of Fourier series with constant or spatially varying coefficients for two purposes: to derive higher order boundary conditions for regular and irregular wave trains and to derive evolution equations on constant or variable water depth.

TL;DR: In this paper, an exact solution for diffraction of short-crested waves incident on a circular cylinder is presented, and the wave load increases as the wave number in the direction perpendicular to the direction of the wave propagation increases, or as the incident waves become shorter.

TL;DR: In this paper, a quasi-vortex-lattice method was applied to predict the propulsive performance of three naturally occurring oscillating propellers, which were cetacean flukes for a fin whale (Balaenoptera physalus), white-sided dolphin (Lagenorhynchus acutus); and white whale (Delphinapterus leucas).

TL;DR: An analytical solution for the coupling problem of a two-dimensional tension leg structure interacting with a monochromatic linear wave train in an inviscid and incompressible fluid is presented in this article.

TL;DR: In this paper, the authors describe the main recommendations in the document produced and the philosophy behind them and discuss some aspects of sampling variability, including the problem of how far apart two wave sensors have to be to give independent estimates of the wave spectrum.

TL;DR: In this article, the authors deal with the solution of the title problem using the well-known normal mode, sinusoidal eigenfunction expansions, and show that the system then exhibits a more complex behavior than in the case of rigid attachment.

TL;DR: In this article, the wave period, as a function of the distance from the wall, exhibits some negative discontinuities at the nodes and the antinodes tend to disappear starting one wave length from a reflecting wall.

TL;DR: In this paper, the authors assess the influence of front wall inclination on the magnitude of breaking wave pressures and conclude that a maximum pressure of 105% can be expected for a 10° forward inclined wall.

TL;DR: In this article, a numerical model was developed to investigate the behavior of a pair of flexible, floating breakwaters consisting of complaint, beam-like structures anchored to the sea bed.

TL;DR: In this paper, the influence of a quadratic viscous drag nonlinearity in multi-point mooring systems is examined in the presence of a nonlinear restoring force and a coupled wave-structure exciting force.

TL;DR: In this article, the diffraction of regular water waves by an array of uniform vertical circular cylinders in a channel is considered using a linear wave theory and solutions are obtained numerically using the Boundary Element Method and these are compared with their open sea equivalents.

TL;DR: In this article, a large oil tanker moored to an articulated mooring tower can be modeled as a bilinear oscillator, that is, a linear oscillator with different stiffnesses for positive and negative deflections due to the slackening of moorings lines.

TL;DR: In this article, the specific power output of a real thermoelectric OTEC plant is analyzed and optimized and compared with that of the Carnot OTEC, endoreversible OTEC and external reversible OTEC.

TL;DR: In this paper, a laser Doppler anemometer is used to measure the horizontal velocity under the largest wave occurring in an irregular sea generated in a laboratory wave tank and the results are not consistently predicted by either of the stretching methods, and therefore, it is not known which method will give a more accurate prediction before the data are measured.

TL;DR: In this paper, the behavior of rigid piles under cyclic lateral loading has been studied through an experimental program carried out on model piles embedded in a soft marine clay, and the results of post-cyclic load tests indicate that the behaviour under static load can improve for cyclic load levels less than 40% of the static lateral capacity.

TL;DR: In this paper, an indirect tension measurement method of a towing cable in midwater or a buoy cable is proposed using underwater acoustic positioning systems, etc., to give the in-water cable tension.

TL;DR: In this article, the flow field generated by a Rankine body moving under a free surface in an infinite depth water is calculated by potential theory using highly efficient and adaptive quadratures of the QUADPACK library.

TL;DR: In this article, a spectral density function obtained from a wavestaff and a free floating buoy is compared with the observed discrepancies between Waverider and WAVestaff measurements in the WADIC project.

TL;DR: In this article, the relative velocity drag term of Morison's equation is used in conjunction with frequency domain first-order motion transfer functions to compute the drift forces and moments on floating platforms in regular and random waves.

TL;DR: In this paper, a semi-analytic approach is presented to predict the static performance of marine cables, and the solution is derived as a function of only three parameters which can be solved numerically by implementing different kinds of boundary conditions.

TL;DR: In this article, a PC-based software using the Bulirsch-Stoer technique has been developed to solve the initial-value problem so as to deduce the body motions from the measured accelerations.

TL;DR: In this article, the authors measured the wave-induced dynamic pressures around surface piercing twin-tandem rigid vertical circular cylinders fixed at the bottom of a wave flume, obtained using the source distribution method, compared with the measured values.

TL;DR: In this article, a test was performed to determine the effect of a two-dimensional shear current on a submerged horizontal circular cylinder, and three types of current were developed: positive shear, no shear (uniform) and negative shear.

TL;DR: In this article, a 2DOF system for a tanker moored to an articulated loading platform (ALP) is modeled by a 2-DOF restoring function, and the sensitivity of the dynamic response of the strong nonlinear system with respect to system parameters and initial conditions is examined.

TL;DR: In this paper, a generalization of a computational method for the linearized potential flow, previously applied to a two-step vertical cylinder, is presented for the study of hydrodynamic forces on a cylinder with a large number of steps.

TL;DR: In this paper, the added mass theory is used in a momentum analysis in connection with the vertical impact of a wedge in a planing boat spray, and the analysis which follows appears to support that conjecture, in that the size of the spray sheets so calculated is the same as those of Pierson's numerical calculations.

TL;DR: In this article, the boundary value problem for a large cylinder fixed parallel to the crests of the oncoming regular waves in a finite water depth using the Green's second identity and linearized potential flow theory is formulated numerically.

TL;DR: In this paper, the authors used the Boundary Element Method (BEM) to study wave pressure acting on a vertical quay, as well as the uplift forces on a submerged plate.

TL;DR: In this article, the authors describe the state-of-the-art evacuation systems for offshore rigs and platforms in the case of cable-launched boats, where a pendulum-like motion of the craft on its cables is set up.

TL;DR: In this article, a tethered spherical float undergoing oscillatory motion in regular waves is analyzed and the difference between float velocity and particle velocity is considerable and in such cases the relative velocity instead of the particle velocity has to be considered for drag force or drag power estimation.