ROTOR BLADE Russian patent published in 2009 - IPC B64C27/467 

FIELD: aircraft engineering.

SUBSTANCE: rotor blade (1) consists of blade shank and blade feather with their profiles formed by lower, upper and front flat surfaces. Blade incorporates cells (2) with ridges (3) arranged therein from upper (4) to lower edges of the blade, ridge height and width increasing. Blade lower edge ridges (3) begin with a flat rounded rib extending beyond blade upper edge by 1.5% to 1.7% of blade width to make the 110°-angle with blade upper edge. Ridge inner side is inclined to height from its base for 42° to 45°. Ridge base varies from 1/5 to 1/3 of cell length. Ridge inner surface and blade lower edge make the 45°-angle, while outer edge make the 120°-angle therewith. Ridge inner surface features slot (8) narrowing downward to make a flute. Ridge height and, respectively, slot are maximum nearby blade shank and decrease, coming towards blade end, from 1/3 of blade length, successively and each, by 10% as compared with initial value.

EFFECT: higher efficiency of rotor, reduced noise.

1 dwg