Experimentell studie av spraydeflektorer till planande skrov

Planning vessels can reach high operational speeds thanks to their hull design. Some hull forms will develop large volumes of spray attached to the hull surface. The whisker spray is a thin layer consisting in droplets of water which can ac-count for a large proportion of the total resistance. A new concept to redirect the spray, called de°ectors, has been developed by the Swedish company Petestep. These de°ectors indicate higher e˝ciency than the time-proven spray rails tech-nology by removing a bigger portion of the spray area. The spray is re°ected back-wards rather than to the sides, which allows kinetic energy contained in the spray sheet to be converted to additional forward thrust. However, there have only been a few studies conducted on the e˛ects of de°ectors and there is no precise method to analyze their e˝ciency over the full range of operating speeds. For the above-mentioned reason, experimental testing is needed to have a more complete under-standing of the phenomenon in calm water and waves. In this study, model scale tests of a modular planning hull are carried out at the Davidson Laboratory towing tank. The goal is to verify the beneÿts of the spray de°ectors by direct comparison with the bare hull conÿguration at the same trim angle