초록 ▼

The nozzle of an acoustic jet directs high momentum flux gas particles essentially tangentially into the boundary layer of the flow in a diffuser, an engine air inlet, a jet engine gas flow path or on the suction surface of an airfoil, the gas particles in the chamber of the tangential acoustic jet

The nozzle of an acoustic jet directs high momentum flux gas particles essentially tangentially into the boundary layer of the flow in a diffuser, an engine air inlet, a jet engine gas flow path or on the suction surface of an airfoil, the gas particles in the chamber of the tangential acoustic jet being replenished with approaching low momentum flux particles drawn from the gas flow in a direction normal to the surface, thereby to provide a net time-averaged flow of increased momentum flux particles to defer the onset of boundary layer separation and/or reduce the thickness of the boundary layer. The acoustic jet is driven by a gas pressure oscillation generator which may be a loudspeaker, a resonant solenoid piston, a cranked piston, or the like.

대표청구항 ▼

1. A gas flow system, comprising:a gas flow path adjacent a surface, gas flowing within said path having a boundary layer adjacent said surface; a chamber; a gas pressure oscillation generator for providing gas in said chamber having significant oscillatory pressure components at substantially a sel

1. A gas flow system, comprising:a gas flow path adjacent a surface, gas flowing within said path having a boundary layer adjacent said surface; a chamber; a gas pressure oscillation generator for providing gas in said chamber having significant oscillatory pressure components at substantially a selected frequency; and a gas passage interconnecting said chamber with said gas flow path, said passage directed into said flow at a small acute angle with respect to said surface so that said chamber, said gas pressure oscillation generator, and said passage form a tangential acoustic jet of which said passage forms the nozzle, to provide a stream of high momentum flux gas particles substantially tangentially into said boundary layer which causes, in a region downstream of said nozzle, substantially steady streamline flow with said boundary layer absolutely attached to said surface; and wherein said frequency is selected to provide predetermined mass flow into and out of said chamber, as a function of the physical parameters of said chamber, said nozzle and said gas pressure oscillation generator.