ATTENUATION OF WIND WAVES BY A HYDRAULIC BREAKWATER

Abstract

Waves generated in a tank by air blowing over the water surface were subjected to a horizontal current of water created by horizontal water jets issuing from a manifold at the water surface (hydraulic breakwater). The energy spectra of the waves were computed for conditions before and after the hydraulic breakwater was turned on. It was found that the shorter, steeper wave components were attenuated to a much greater extent than were the longer wave components. Thus, although a large portion of the wave energy could get past such a breakwater, the waves in the lee of the breakwater looked considerably lower to the observer.