초록 ▼

An acoustic jet disposed within an aerodynamic surface, such as a wing or a blade, has a resilient wall supporting a mass. Vibrations of the blade cause oscillatory pressure waves within the acoustic jet, the nozzle of which directs fluid particles having high momentum flux essentially tangentially

An acoustic jet disposed within an aerodynamic surface, such as a wing or a blade, has a resilient wall supporting a mass. Vibrations of the blade cause oscillatory pressure waves within the acoustic jet, the nozzle of which directs fluid particles having high momentum flux essentially tangentially into the boundary layer of the suction surface of the blade, the resonant cavity of the synthetic jet being replenished with particles having low momentum flux drawn from the flow in a direction normal to the surface, thereby to provide a net time averaged flow of fluid particles of increasing momentum flux into the boundary layer to defer or prevent the onset of boundary layer separation. Single and double chambers drive nozzles separated streamwise or spanwise on airfoils (blades, wings) and fuselages. Applications include helicopters, airplanes, air moving machines and wind energy electric power generators.

대표청구항 ▼

[ We claim:] [1.] A structure which vibrates when in operation, comprising:a surface forming a part of said structure and having an aerodynamic profile;a resilient membrane having a concentrated mass disposed thereon;a chamber disposed within said structure, said membrane forming a flexible wall of

[ We claim:] [1.] A structure which vibrates when in operation, comprising:a surface forming a part of said structure and having an aerodynamic profile;a resilient membrane having a concentrated mass disposed thereon;a chamber disposed within said structure, said membrane forming a flexible wall of said chamber, said chamber being located adjacent to a boundary layer separation point of said surface; anda nozzle connecting said chamber with said surface in the vicinity of said boundary layer separation point, vibration of said structure when in operation causing said mass to oscillate at frequencies related to the frequencies of vibration of said structure, thereby producing oscillatory pressure variations in said chamber at frequencies related to the frequencies of vibration of said mass which in turn provides pulses of fluid particles into the boundary layer of said surface at frequencies related to the frequencies of vibration of said structure.