CENTRIFUGAL AIR FLOW CONTROL

摘要

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 suction surface of the blade, thereby delay or prevent the onset of the 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.