Showing papers in "Ocean Engineering in 1990"

TL;DR: In this article, a closed-form solution for the velocity potential resulting from the interaction of second-order Stokes waves with a large vertical circular cylinder was developed, which was then used to determine the theoretical free surface elevations around the cylinder consistent to second order.

TL;DR: In this paper, phase control is used to increase the energy absorption from irregular waves by oscillating water column (OWC) devices, from regular and irregular waves, in a modified version of the self-rectifying axial-flow Wells air turbine.

TL;DR: In this article, the authors measured the impact pressure and resulting wall deflection from breaking oscillatory waves on a vertical wall with 1/10 foreshore slope and found that the longerlasting low impact forces are more effective in producing the larger wall deflections.

TL;DR: In this article, the interaction of a current-free plane surface wave train of fixed frequency and a uniform wave-free current normal to the wave crests in the same or opposite direction to wave propagation is described.

TL;DR: In this paper, an experimental and numerical study is made of the forces and flow about a circular cylinder steadily advancing beneath the free-surface, showing that the drag coefficient abruptly decreases from 1.3 to 1.0 and the Strouhal number simultaneously increases from 0.19 to 0.30 at the depth-radius ratio of 1.7 when the depth of submergence of the circular cylinder is gradually reduced.

TL;DR: In this article, the effects of the dynamic coupling of a liquid-tank system are studied analytically for a two-dimensional, rectangular rigid tank with no baffles, where the governing equations of the liquid motion are derived with reference to a moving coordinate system which is fixed to the moving container.

TL;DR: In this paper, the interaction between current-free higher-order water waves with a wave-free uniform current normal to the wave crests is considered, and the combined wave-current motion resulting from the interaction is assumed stable and irrotational.

TL;DR: In this article, the specific power of a simple irreversible closed-cycle OTEC power plant is analyzed and optimized for maximizing the per unit time and per unit total heat exchanger area production in power plants whose heat transfer area is constrained by economic consideration.

TL;DR: In this paper, it was shown that there were still inconsistencies in the prognostic equations giving overestimation of the first moment of the spectrum and consequently the significant wave height, and that variable σ a, σ b and γ must be used to achieve consistent results.

TL;DR: In this article, the authors present a method for the calculation of hydrostatic properties of intact and damaged ship hulls and other floating structures, where the geometry of the floating structure is modelled as a set of compartments, bounded by flat panels.

TL;DR: In this article, a comparison between two theoretical methods for computing the second-order diffraction loads on arrays of bottom-mounted, surface-piercing vertical circular cylinders in regular waves is presented.

TL;DR: In this paper, the boundary integral method is used to calculate the hydrodynamic pressure distribution on a rigid submerged cylindrical storage tank subjected to horizontal or vertical harmonic ground excitation, where the fluid is assumed to be linearly compressible and to undergo small-amplitude, irrotational motion.

TL;DR: In this article, an extensive experimental program for measuring, recording and analyzing free roll decay curves for three models representative of small fishing vessels was carried out, and the results indicated that a linear plus linear angle dependent form fits best the experimental data of a heavily damped hull.

TL;DR: In this article, a simplified model for the static analysis of the tethers as anchoring elements for a tension leg platform (TLP) was presented, and basic equations for calculating the gross behavior of the TLP tether/platform interaction were also provided.

TL;DR: In this paper, the hydrodynamic pressure due to regular and random waves exerted on a large vertical cylinder in a constant water depth is investigated, and the results of the experiments are compared with the linear diffraction theory of MacCamy, R. C. and Fuchs.

TL;DR: In this paper, the problem of the dynamics of a moored floating object under the action of regular waves is solved numerically as a boundary value problem by use of the finite-infinite element method.

TL;DR: In this article, the flow field about a horizontal cylinder with its axis parallel to the crests in deep water waves is simulated by a finite-difference method based on the Navier-Stokes equation.

TL;DR: In this article, a fourth-order solution for the mean drift induced by a steady train of waves in water of constant depth was derived, which reproduces the observed tendency of the surface drift velocity to rise in shallow water and to level-off in very deep water.

TL;DR: In this article, a finite element model of the dynamic viscoelastic response of marine cables was developed using an updated Lagrangian description of the principle of virtual work and a three-parameter linear visco-elastic constitutive equation for synthetic cables.

TL;DR: Based on the theoretical solution of second order nonlinear random waves, a relationship between the second-order nonlinear spectra and the linear spectra is presented in this paper, and a model which separats the linear spectrum from the target spectra was set up by using nonlinear constrained optimization method.

TL;DR: In this article, an approach based on the influence of transverse velocity was proposed to account for the apparent increase in the drag coefficient of a submerged cylinder undergoing vibration as a result of hydrodynamic forces.

TL;DR: In this article, a scheme for utilizing ocean wave energy to generate a high power laser was examined, which can be used for unguided communication under water or through the atmosphere, and in spacecraft propulsion.

TL;DR: In this paper, the performance of two cable fairings is compared at low Reynolds numbers for flow normal to the leading edge and with the fairings swept, and the cross-flow model, or independence principle, appears to work surprisingly well.

TL;DR: In this article, the lateral stability of a submarine hoseline in a slowly varying current is investigated, where the hose segment is assumed to slide on the sea bottom without twisting and the stability is evaluated in terms of lateral deflections, hose tensions, and anchor loads.

TL;DR: In this paper, the authors outline a procedure for reliability estimation of structural members in extreme stress and fatigue limit states, using a spectral approach for the extreme response statistics with stochastic loading, and the fatigue reliability is estimated with a narrowbanded stress assumption with discrete, but significant sea states within the life of the structure.

TL;DR: In this paper, the dynamic response of a damaged, twin pontoon, four column semisubmersible at a scale of 1:100 is discussed, with the model oriented in head, beam and quartering directions for both intact and damage conditions.

TL;DR: In this article, it was shown that a planing plate only has fluid on one side (the high pressure side) of the plate, and that the fluid in contact with the plate travels more slowly as the plate trim angle (and therefore static pressure) increases.

TL;DR: In this paper, the in-line and transverse forces on a smooth circular cylinder placed horizontally near a plane boundary are analyzed in the time domain, and the time histories of intantaneous water surface elevation and the corresponding in-lines and transversal forces are Fourier decomposed into various frequency components.

TL;DR: In this paper, the authors describe the design of a seawater supply system installed at the University of Connecticut's Noank laboratory on Long Island Sound, which eliminates biofouling by uninterrupted rapid flow (> 2.5 m/sec).

TL;DR: In this article, an autoregressive wave force model is developed which is capable of accounting for localized flow history effects, and the optimal length of the filter and its sensitivity are illustrated using data from small-scale wave tank tests.