SHIPBORNE SCREW PROPELLER Russian patent published in 2010 - IPC B63H1/14 B63H1/26 

FIELD: construction.

SUBSTANCE: screw propeller comprises hub, blades with asymmetrical contour, cylindrical sections of which have variable pitch and curvature. Contour of blades is arranged with skewback towards the side of screw propeller rotation due to forward displacement of blade cylindrical sections from axial line by 65÷80% of their length at relative radius of 0.8÷0.9 that smoothly reduce down to 0% near hub. Besides contours of blade butts do not cover each other in axial direction of screw propeller and create gap. Edge sharpening is arranged near blades, on their two sides, at inlet edge, starting from axial line of blade on external radius and to relative radius r≈0.3 of blade cylindrical section. Angles of sharpening make 30° at suction side, and 12° - at discharge side.

EFFECT: improved hydrodynamic and acoustic characteristics of screw propellers, reduced cavitational noise and simplified design of their manufacturing.

2 cl, 3 dwg