Showing papers in "Ocean Engineering in 1992"

TL;DR: In this paper, the second-order theory explains a significant portion of the nonlinear wave run-up distribution measured at all angles around a large diameter vertical circular cylinder, and the design curves are presented for estimating the maximum secondorder wave runup for a wide range of conditions in terms of the relative depth, relative cylinder size, and wave steepness.

TL;DR: The 3-m diameter discus buoys that the National Data Buoy Center for the U.S. National Oceanic and Atmospheric Administration now uses routinely to measure ocean directional wave data are now in the national archives.

TL;DR: In this article, a series of small scale wave tank tests on four column TLP models examining wave run-up on the vertical legs and the amplification of the waves beneath the deck are reported.

TL;DR: In this article, the wave transmission and reflection by a partially immersed rigid vertical barrier was studied in detail in deep water conditions by measuring the transmitted and reflected wave histories, and the experimental investigations were carried out for a wide range of wave steepness, at different depths of immersion of the barrier in a wave flume 0.3 m wide, 10 m long and in a constant water depth of 0.8 m at Ocean Engineering Centre, Indian Institute of Technology, Madras, India.

TL;DR: In this paper, the wave transmission and reflection characteristics of a rigidly fixed surface and submerged horizontal plate were investigated experimentally in detail for a wide range of incident wave steepnesses and for different depths of submerge of the plate in deep water conditions in regular water wave fields.

TL;DR: In this article, the authors carried out numerical computations of water impact on a two-dimensional flat-bottomed body using a volume-of-fluid method based on a modified SOLA-VOF code.

TL;DR: In this paper, a simulation methodology is introduced to retain the essential features of the theoretical background in Gaussian random noise but to avoid further compromising assumptions in the interpretation of wave height and period in the amplitude domain.

TL;DR: In this article, the sensitivity of a tri-articulated tower to a tension-restrained articulated platform (TRAP) for use in 914 m (3000 ft) of water is compared to a TRAP for comparison in the sensitivity studies.

TL;DR: In this paper, a theoretical model for the water entry of a free-fall lifeboat is derived by extending the concepts for cylinder impact and seaplane landing, and a practical method for simulating the water entering of a boat is proposed.

TL;DR: In this paper, the frequency coefficients for three combinations of boundary conditions: simply supported, simply supported and clamped at both ends were obtained for three different boundary conditions, and the results showed that simply supported is the best boundary condition.

TL;DR: In this article, Boef et al. presented a method for simulating the water entry of a free-fall lifeboat, when dropped from an offshore platform or from a ship, in order to assess the risk of injury to occupants.

TL;DR: In this article, a three-dimensional numerical model for determination of the interaction between non-linear water waves and a structure is developed based on a boundary integral equation method for the spatial solution of a potential theory problem, combined with a time-stepping method based on the fully nonlinear free surface conditions.

TL;DR: In this article, a simple non-autonomous system with quadratic damping and parametric excitation was used to predict the stability of the tether and regions of unstable solutions, phase plane portraits and Poincare maps were constructed.

TL;DR: In this paper, the authors derived the probability density function of the extreme base shear, that is, the extreme value of the total horizontal force exerted by storm waves and currents, in a storm interval.

TL;DR: In this paper, a constant tension winch controller was designed to minimize peak tension loads encountered while towing heavy gear in rough sea conditions, and the control unit consists of a pressure relief valve inserted in the hydraulic circuit of the winch.

TL;DR: Payne as discussed by the authors gave an approximate added mass variation with chines immersed and also presented the conventional "cross-flow force" hypothesis as an additional lift component, so that adding the two together results in a chines-insulated dynamic force which is twice the correct value.

TL;DR: In this article, a boundary integral equation combined with a non-linear time stepping procedure for the free water surface is developed for simulations of the interaction between highly nonlinear water waves and submerged horizontal cylinders.

TL;DR: In this paper, the added mass and damping coefficients of a tethered spherical float, undergoing oscillatory motion in sinusoidal waves, have been derived from the motion generated velocity potential for one degree-of-freedom (surge) using potential flow theory.

TL;DR: In this paper, a parametric analysis of the wind generated wave spectrum is presented to determine if a sea is locally developed from the knowledge of the significant wave height, peak spectral period and nominal wind speed.

TL;DR: In this article, a three-dimensional finite element model is used to determine the states of dynamic stress in dolosse with varying dimensions and concrete properties, and an analytical procedure is developed which accurately predicts the tensile stress in the shank and horizontal fluke of dolosa subject to drop test loading conditions.

TL;DR: In this paper, a method of predicting wind wave run-up (for any desired quantile or statistic value) on smooth linear mild slopes has been presented based on a re-analysis of an extensive laboratory measurement runup data base of Mase.

TL;DR: In this article, the authors proposed a simple piping system consisting of two or more vertical, insulated pipes connected horizontally by a heat exchanger, which has some similarities with the "salt fountain" proposed by Stommel and collaborators over 30 years ago.

TL;DR: In this paper, the authors present the verification of the UNO-HYF1 with published performance data and show the change with speed when the foil area, foil angle and propeller shaft angle are changed.

TL;DR: In this paper, a PC-based program called WEDGE is presented to calculate the influence on the planing hull drag from fitting wedges or trim tabs, and compared with published examples of a 25 m motor yacht and power boat.

TL;DR: In this article, a comprehensive analysis of the dynamic response of simple models of offshore structures to assess the effects of numerous factors involved was made. But the authors focused on the response of changes in the relative magnitudes of the inertia and drag force components, of the current velocity, and of fluid-structure interaction.

TL;DR: The first part of this paper is mainly concerned with the development of the computer codes for the boundary element method with mixed boundary conditions (Cauchy type boundary conditions), which are applied to three practical problems whose analytical solutions are known to illustrate the usefulness of the method as discussed by the authors.

TL;DR: The Direct method and the Poisson clumping method are found to have comparable accuracy, and the Log-fit method is the simplest to implement, and computationally the most efficient.

TL;DR: In this paper, the fundamental frequency coefficients of the structural system described in this paper were determined using the optimized Rayleigh-Ritz method and the results were in good engineering agreement with the values obtained by means of a finite element code.

TL;DR: In this article, the maximum bottom shear stress in neutrally stable planetary boundary layer flow is derived by using similarity theory and the results are obtained for flow conditions in the rough, smooth and transitional smooth-to-rough turbulent regime.

TL;DR: In this paper, a multivariate or joint probability density function for wave forces has been developed for the peak force distribution of wave forces, where peak force is defined by the Morison equation.