Wave height

About: Wave height is a research topic. Over the lifetime, 5920 publications have been published within this topic receiving 100257 citations.

Experimental determination of run‐up of undular and fully developed bores

Abstract: The run-up of undular surge and bore is determined experimentally for four slopes each with three different bottom roughnesses. Results indicate that dimensionless run-up curves of the height of run-up versus the height of the initial wave are approximately linear for the undular surge, F ≤ 1.35, and the fully developed bore, F ≥ 1.55, separated by a nonlinear transition region. The run-up is strongly affected by both slope and bottom roughness. Empirical prediction equations are given in the form h/y2 = ƒ1 (sin α, ƒ) + ƒ2 (sin α, ƒ) y2/y1, where h is run-up height above undisturbed water level, α is the slope angle, ƒ is a dimensionless friction coefficient, y2 is the height of the wave measured from the channel bottom, and y1 is the undisturbed water depth. Experimental data on run-up and changes in structure and celerity of the wave front during progression up slope disagree in several fundamental aspects with now published relevant theory based on the nonlinear long-wave equations. In particular, the prediction equation for run-up in the form u02/2g, independent of beach slope, is shown not to hold true, and the theoretical conclusion that the bore height η collapses to zero at the intersection of undisturbed water level with slope is also shown not to hold true for the conditions under which the present experiments were made. The predicted relationship between piston velocity V and wave height y2 is verified experimentally, and the predicted relationship between wave celerity C and y2 fits the experimental data provided that one takes into account the effects of wall and bottom roughness and the wide fluctuations in the wave front in the fully developed bore phase.

Hydrodynamic Characteristics of Pile-Supported Vertical Wall Breakwaters

Abstract: This paper describes the hydrodynamic characteristics of a pile-supported vertical wall breakwater, the upper part of which is a vertical wall, and the lower part consisting of an array of vertical piles. For regular waves, using the eigenfunction expansion method, a numerical model has been developed that can compute wave transmission, reflection, and run-up, and wave force acting on the breakwater. For irregular waves, the regular wave model is repeatedly used for each frequency component of the irregular wave spectrum. The wave period is determined according to the frequency of the component wave, while the root-mean-squared wave height is used for all the component waves to compute the energy dissipation between piles. To examine the validity of the developed models, large-scale laboratory experiments have been conducted for pile-supported vertical wall breakwaters with a constant spacing between piles but various drafts of the upper vertical wall. Comparisons between measurement and prediction show that the numerical model adequately reproduces most of the important features of the experimental results for both regular and irregular waves. The pile-supported vertical wall breakwater always gives smaller transmission and larger reflection than a curtain wall breakwater with the same draft as that of the upper wall, or a pile breakwater with the same porosity as that of the lower part, of the pile-supported vertical wall breakwater.