Showing papers on "Wave flume published in 1970"
TL;DR: In this article, the theory of mass transport in water waves is re-examined and boundary-layer arguments are incorporated into the Lagrangian equations of motion, and the mass transport velocity is conveniently derived for both monochromatic and random waves.
Abstract: The theory of mass transport in water waves is re-examined. Boundary-layer arguments are incorporated into the Lagrangian equations of motion, and the mass transport velocity is conveniently derived for both monochromatic and random waves. For finite depth, Longuet-Higgins' result is confirmed. Conditions at the far end of a wave tank are found to be related to a mean pressure gradient, and results are also obtained for a truly infinite channel. The nonuniformity of the solution for the deep-water limit is discussed.
80 citations
TL;DR: In this article, a theory for evaluating the response of offshore structures to random wave action is described by the linear wave theory and the Gaussian processes, and the hydrodynamic forces are computed through the Morrision O'Brien-Britschneider formula.
Abstract: Response of offshore structures to random wave action is presented. A theory for evaluating the response of these structures in deep water is described by the linear wave theory and the Gaussian processes. Hydrodynamic forces are computed through the Morrision-O’Brien-Britschneider formula. Some results of this application to several towers are given.
25 citations
TL;DR: In this paper, the authors developed criteria for the design of a wave barrier to protect the proposed Honolulu International Airport Reef Runway from breaking waves using wave flume model tests, where tribar and quarrystone armor units placed in single and multiple layers on homogeneous and composite slopes were subjected to both overtopping and non-overtopping breaking waves.
24 citations
TL;DR: In this article, a method for calculating ocean wave forces on offshore drilling structures is proposed based upon data from two full-scale wave force measurement installations in the ocean, and a mathematical model representing hydrodynamic forces on submerged bodies in unsteady flow and the kinematic flow field of highly nonlinear waves.
Abstract: This method for calculating ocean wave forces on offshore drilling structures is based upon (1) data from two full-scale wave force measurement installations in the ocean, and (2) a mathematical model representing hydrodynamic forces on submerged bodies in unsteady flow and the kinematic flow field of highly nonlinear waves. The method is applicable to a broad range of wave conditions commonly encountered in offshore structure design. Several comparisons show that the method represents measured forces satisfactorily for engineering design.
22 citations
TL;DR: In this paper, a new electrolytic turbulence transducer has been developed in order to measure the turbulent velocity fluctuation superposed on the oscillatory flow velocity, which is induced by ripples which appear on the movable bed of wave flume and the correlation between the turbulence intensity and the characteristics of sediment particles at the same level such as their fall velocity and sediment concentration.
Abstract: A new electrolytic turbulence transducer has been developed in order to measure the turbulent velocity fluctuation superposed on the oscillatory flow velocity The aim of the present paper is firstly to describe the outline of this transducer and secondly to introduce some of the experimental results The main items of the results are, l) the vertical distribution of turbulence intensity averaged over one wave cycle, where the turbulence is induced by ripples which appear on the movable bed of wave flume, and 2) the correlation between the turbulence intensity and the characteristics of sediment particles at the same level such as their fall velocity and sediment concentration.
18 citations
TL;DR: In this article, a plate whose edge was hinged at the water surface was dropped into a water basin, and measured the resulting pressure on the plate by piezoelectric type cells.
Abstract: Shock pressures caused by impact between a solid and a liquid, such as the case of waves breaking against coastal structures, could better be described as an elastic wave wherein the elasticity of the solid and the compressibility of the liquid are taken into consideration. Tests were conducted to study the probability of occurrence of shock pressures as high as the theoretical pressure predicted by the elastic wave approach, for the case of waves breaking against coastal structures. The tests consisted of dropping a plate whose edge was hinged at the water surface, into a water basin, and measuring the resulting pressure on the plate by piezoelectric type cells. The probability distributions of the ratio between the magnitude of the recorded and the theoretical pressure, and of the duration of pressure were found to fit Poissons distribution well at the 5% level of significance. These distributions could serve as a guide for predicting the magnitude and possibly the duration of shock pressure to which coastal structures might be subjected.
12 citations
TL;DR: In this article, two numerical models for linear wave propagation, wave induced circulation and sediment transport are presented for a compound wave field near coastal structures where the waves are subjected to the combined effects of shoaling, refraction, diffraction, reflection (total and partial) and breaking.
Abstract: In the present work two numerical models for linear wave propagation, wave induced circulation and sediment transport are presented. The wave model WAVE-L is based on the hyperbolic type mild slope equation and is valid for a compound wave field near coastal structures where the waves are subjected to the combined effects of shoaling, refraction, diffraction, reflection (total and partial) and breaking. Radiation stress components estimated from the hyperbolic wave model drive the depth averaged circulation model COAST for the description of the nearshore currents and sediment transport in the surf and swash zone. The model COAST is coupled with a 3D bed evolution model or with an one-line model to provide bathymetry or shoreline changes.
6 citations
TL;DR: In this paper, the development of laboratory equipment to simulate the water particle motion at the sea bed due to wave action is described, which oscillates a block of water horizontally in a flume.
Abstract: The development of laboratory equipment to simulate the water particle motion at the sea bed due to wave action is described. Essentially, it oscillates a block of water horizontally in a flume. An inverted U-frame constraining the water measures 84 in. long by 48 in. wide by 24 in. high and is large enough to reproduce prototype boundary conditions. A piston drive is supplied by high pressure oil and motion is controlled to follow a sinusoidal input movement. Previous attempts to model wave action for the study of sediment movement are analyzed and the benefits of the present design are outlined. It is proposed that the equipment be used to study the effects of superimposed wave trains and mass transport velocity on sediment movement.
3 citations
TL;DR: In this paper, a wave flume based on boundary integral equation (BIE) was used to study deep water wave breaking due to large periodic displacements of the wave paddle, and it was shown that the point of breaking is when the maximum vertical and horizontal accelerations are at g and 1.56g, respectively.
Abstract: A fiilly nonlinear 2-dimensional numerical wave flume, based on the boundary integral equation method, has been developed. Waves are generated by a hinged paddle wave maker at one end of the flume and a sponge type wave absorber at the other end. A fourth order Taylor expansion technique is used for the time stepping of the free surface. Simple monochromatic waves have been generated and very good agreements are found when compared with Stokes wave profiles. The wave flume is used to study deep water wave breaking due to large periodic displacements of the wave paddle. Wave breaking as a result of energy focusing a group of waves of different frequencies and heights, is also studied. For each breaking event, breaking wave parameters such as the wave steepness, breaking height, particle velocities and accelerations are examined in detail. There does not appear to be a definable correlation between the point of breaking, the wave steepness, or the particle velocities. The maximum downward (vertical) and forward (horizontal) accelerations at breaking are found to be independent of the initial conditions, with constant values of g and 1.56g, respectively; and where g is the acceleration due to gravity. It has been proposed (Philips*) that particle accelerations could be used as a criterion for wave breaking. Positive verification of this was first provided in an earlier study by the authors She et af, which used spatially periodic boundary conditions. Both studies support Philips' conjecture, and suggest that the point of breaking is when the maximum vertical and horizontal accelerations are at g & 1.56g. Transactions on the Built Environment vol 40 © 1999 WIT Press, www.witpress.com, ISSN 1743-3509