WATER-JET PROPELLER Russian patent published in 1996 - IPC

FIELD: shipbuilding. SUBSTANCE: water-jet propeller has water conduit with axial-flow pump arranged in it. Water conduit is made in form of annular wing with axial extent equal to 2-4 diameters of pump impeller and number of blades no less than 11; ends of blades are connected with short nozzle whose length does not exceed 0.15 diameter of impeller; rear portion of this nozzle is sunken in water conduit and front portion is spaced apart from inner surface at a distance of 0.01 to 0.015 of impeller radius. EFFECT: improved propulsive properties of water-jet propellers; reduction of before-cavitation noise and vibration caused by operation of propeller in irregular flow behind water-craft hull. 1 dwg