Wetzel, J. M.2011-07-062011-07-061955-05https://hdl.handle.net/11299/108484Pilot studies of pneumatic, and vertical and horizontal hydraulic breakwaters were conducted in a small glass-walled wave channel to determine the effect of various parameters on wave attenuation. The data are preliminary and are to be checked in a large wave tank. A theory of the pneumatic breakwater by G. I. Taylor is briefly summarized, and part of this theory is verified by experimental data. In the experimental studies, emphasis was placed on tests of the vertical and horizontal water-jet breakwaters. The parameters considered were wave length, wave steepness, water depth, jet discharge, jet velocity, and jet submergence. In general, wave steepness was of minor importance. Both the pneumatic and hydraulic breakwaters proved to be effective in attenuating deep-water waves, but neither were effective for shallow-water waves. The power requirements of the vertical water jets for a specific wave length to water depth ratio (L/d) and attenuation were considerably higher than the horizontal water jets; the pneumatic breakwater required less power that the horizontal water jets in the larger L/d region.en-USReport