Abstract
In order to examine the effect of microbubbles on frictional resistance, resistance tests and paint test for a flat plate covered by microbubbles were carried out in a towing tank. The flat plate of 3.5m long was set horizontally and towed by a carriage. Porous plates to generate microbubbles were installed on the lower surface of the flat plate. It was found that injection of microbubbles is effective for the reduction of frictional resistance, and the degree of reduction of frictional resistance is changed considerably by air flow rate and towing speed of the flat plate. The reduction of frictional resistance persists for far downstream of the injection section.
