Patent ID: 6078674
Filing Date: 2000-06-20
Classification: B64C,G10K

Abstract:
A system for reducing flow-induced resonance in a cavity that is formed in a surface of a structure where said cavity has a plurality of resonant frequencies and where a flow moves over said structure and past said cavity such that a leading edge and a trailing edge of said cavity are defined with respect to the direction of said flow, said flow being attached to said surface prior to said leading edge and separating from said surface at said leading edge to generate a shear layer originating at said leading edge, said system comprising:a housing contained within said structure;at least one pair of diaphragms mounted in said housing, each pair of diaphragms having a first diaphragm and a second diaphragm separated from one another such that a chamber is formed therebetween within said housing;an actuator coupled to said at least one pair of diaphragms for oscillating said first diaphragm of said each pair of diaphragms in accordance with a time-varying function and for oscillating said second diaphragm of said each pair of diaphragms inversely to said first diaphragm wherein pressure in said chamber changes in correspondence with said time-varying function; andplumbing coupled to each said chamber and terminating in at least one vent positioned flush with the surface of said structure along said leading edge of said cavity wherein said pressure in said chamber changing in correspondence with said time-varying function introduces a corresponding time-varying disturbance into said shear layer such that energy available in said shear layer interacting with said cavity to generate resonance at at least one of said plurality of resonant frequencies is reduced.