Abstract: Micro-bubble generators attached to a ship hull below the waterline decrease frictional resistance during navigation and improve fuel efficiency. Each micro-bubble generator is supplied with air and has a wing positioned outside the hull for generating negative pressure. The negative pressure created by the wing increases with an increase in ship's speed, which pushes the air-liquid interface outwardly toward the wing. As the air and the water move at different speeds due to difference in their densities, micro-bubbles are generated in the micro-bubble generator according to the Kelvin-Helmholtz Instability mechanism and discharged downstream to move closely along the outside surface of the hull.

Abstract: [Object] The present invention provides for a frictional resistance reduction ship able to decrease friction resistance and improve fuel efficiency. [Solution] When the navigation speed increases, and negative pressure which is created by the wing 33 increases, a result is that the air-liquid interface is pushed down further. Due to the air and the water (sea water) moving different speeds, density differs between air and water (as shown in FIG. 7), micro-bubbles are generated in the micro-bubble generator according to the Kelvin-Helmholtz Instability mechanism, and these micro-bubbles flow through onto the downstream side along the hull.