Patent ID: 7194862

Claim:
A resonator for damping pressure waves supported by acoustic energy in a system having a flow path, the resonator comprising: a) a first member; b) a first plurality of openings through the first member; c) a second member maintained in a generally spaced relation to the first member wherein a volume is defined between the first member and the second member and the first member is situated upstream of the second member within the flow path; d) a second plurality of openings through the second member, the first plurality and the second plurality of openings being in fluid communication with the flow path so that air passes through the volume; e) an upstream portion within each of the second plurality of openings wherein each upstream portion has a first diameter and a first length; and f) a downstream portion within each of the second plurality of openings wherein each downstream portion has a second diameter and a second length and wherein the first diameter is different the second diameter and the first length is different than the second length.