초록 ▼

Blades, including helicopter rotor blades, gas turbine engine fan blades, air moving machinery fan blades, and the like, have an air inlet near the hub of the blade, which may be on the pressure side of the blade and/or near the leading edge or trailing edge nearer the tip of the blades, with an air

Blades, including helicopter rotor blades, gas turbine engine fan blades, air moving machinery fan blades, and the like, have an air inlet near the hub of the blade, which may be on the pressure side of the blade and/or near the leading edge or trailing edge nearer the tip of the blades, with an air plenum between the air inlet and the slots, whereby air is forced into the inlet, through the plenum and out of the slots into the flow adjacent the blades. The slots may be through the suction surface of the blade, typically near the boundary layer separation point, so that air flowing out of the slots into the boundary layer of the suction surface of the blade, thereby delay or prevent the onset of boundary layer separation, or to reduce supersonic shock. The inlet may be near the trailing edge of the blade, near the root, adjacent to the air inlet of the core of a jet engine, to suction off air and reduce fan wake blockage at the core inlet. The slots may be through the pressure surface adjacent the blade tip edge of fan blades to reduce blade tip leakage effects.

대표청구항 ▼

[We claim:] [1.]a hub, a leading edge, a tip, a root, a pressure surface and a suction surface;an air inlet extending through the pressure surface of said blade near said hub;a plurality of slots extending through the suction surface of said blade closer to said tip than to said hub near the boundar

[We claim:] [1.]a hub, a leading edge, a tip, a root, a pressure surface and a suction surface;an air inlet extending through the pressure surface of said blade near said hub;a plurality of slots extending through the suction surface of said blade closer to said tip than to said hub near the boundary layer separation point of said suction surface; anda plenum within said blade extending from said air inlet to said slots. whereby as said blade rotates, air is forced into said air inlet and driven by centrifugal force along said plenum to exit from said slots into the flow of air adjacent said blade.