HULL FRICTION RESISTANCE REDUCING DEVICE

PROBLEM TO BE SOLVED: To reduce the friction resistance of a hull, and to save energy by blowing out micro bubbles of a gas/water mixed phase so as not to separate from a hull surface. SOLUTION: The hull friction resistance reducing device has a tank storing gas/water mixed phase fluid, a pump 24 supplying the gas/water mixed phase fluid 14 from the tank 22 to a nozzle, and the nozzle blowing out the gas/water mixed phase fluid supplied from the pump to a stern along a hull wall. A controlling means controlling the flow speed of the gas/water mixed phase fluid blowing out from the nozzle so as to be smaller than a wall surface speed incline of a border layer corresponding to present ship speed by inputting a ship speed signal is provided. To the tank, a gas/water mixed phase fluid producing means producing micro bubbles by inducing gas to a turning swirling current center by fluid and shearing a center gas flowing pipe with a swirling current is connected. COPYRIGHT: (C)2008,JPO&INPIT