Showing papers on "Wave flume published in 1975"

Laboratory Investigation of Wave Breaking. Part 2. Deep Water Waves

Abstract: : This study represents the first known attempt to examine in some detail the flow dynamics of the terminal growth and breaking of periodic surface waves in deep water, under controlled and reproducible laboratory conditions. This work was considered a necessary preliminary to future studies of storm wave breaking, a phenomenon of considerable engineering importance that has received little scientific attention. In the present study, a tape-controlled servo- paddle system produced single-frequency, deep water wave trains, which were laterally converged to the breaking point within a tapered channel. Using high- response elevation and velocity sensors, profiles and internal velocity fields of growing waves were determined as functions of time and distance before and after breaking.

Waves of maximum height on uniform currents.

Abstract: Offshore design often involves the use of maximum wave height for a given water depth, yet the presence of a current is usually neglected. A constant current, having the same magnitude over the water depth, can be simply included in design by relating the wave propagating on a current to an equivalent wave propagating in still water. By relating the maximum height values for still water to those on a current, a breaking index curve is generated for waves on uniform currents. The effect of the current on the wave crest displacement is also examined. Finally, a curve is presented to show the magnitude of the maximum opposing currents for which wave groups can propagate upstream. Two examples are provided to illustrate the use of the results.

Analysis of random waves in shallow water and laboratory reproduction

Abstract: Wave measurements carried out in the Elbe estuary give an almost complete survey of the wave motion, allow common derivations about waves in shallow water, and led to a comprehensive presentation of shallow water waves as a function of three topographical parameters. The wave climate can be expressed in terms of these parameters and leads to means and significant heights and periods and representative cumulative distributions. These distributions were used in model tests in order to get an impression of run-up distributions on dike slopes as a function of the wave spectra. The first results show remarkable differences between regular waves and the wave spectra.