Abstract: Extracting energy from wind. At least some of the illustrative embodiments are methods including: directing fluid flow across an aperture of a nozzle in operational relationship with an resonant cavity, a central axis of the nozzle and the central axis of the resonant cavity nonconcentric, and the resonant cavity has a resonant frequency; creating pressure waves within the resonant cavity, the pressure waves created at least in part by vortices within the fluid flow across the aperture; and extracting energy from pressure waves within the resonant cavity.

Abstract: Extracting energy from wind. At least some of the illustrative embodiments are methods including: directing fluid flow across an aperture of a nozzle in operational relationship with an resonant cavity, a central axis of the nozzle and the central axis of the resonant cavity nonconcentric, and the resonant cavity has a resonant frequency; creating pressure waves within the resonant cavity, the pressure waves created at least in part by vortices within the fluid flow across the aperture; and extracting energy from pressure waves within the resonant cavity.

Abstract: Extracting energy from wind. At least some of the illustrative embodiments are methods including: directing a fluid flow across an aperture of an elongated cavity, the directing the fluid flow across the aperture at a non-right angle to a central axis defined by an entrance portion of the elongated cavity, and the elongated cavity has a resonant frequency; creating pressure waves within the elongated cavity, the pressure waves created at least in part by vortices within the fluid flow across the aperture; exciting a resonant structure by way of the pressure waves within the elongated cavity, the resonant structure coupled to the elongated cavity and the resonant structure configured to resonant at substantially the resonant frequency; and extracting energy from oscillatory motion of the resonant structure.

Abstract: Extracting energy from wind. At least some of the illustrative embodiments are methods including: directing a fluid flow across an aperture of an elongated cavity, the directing the fluid flow across the aperture at a non-right angle to a central axis defined by an entrance portion of the elongated cavity, and the elongated cavity has a resonant frequency; creating pressure waves within the elongated cavity, the pressure waves created at least in part by vortices within the fluid flow across the aperture; exciting a resonant structure by way of the pressure waves within the elongated cavity, the resonant structure coupled to the elongated cavity and the resonant structure configured to resonant at substantially the resonant frequency; and extracting energy from oscillatory motion of the resonant structure.