Patent ID: 6112514
Filing Date: 2000-09-05
Classification: B64D,F02C,F04D,F05D,G10K,Y02T

Abstract:
A noise reduction system comprising:means for generating non-uniform noise energy about an inner surface and within an enclosure having at least an inlet;at least one array of tubes each having an inlet and an outlet, the inlet and the outlet of each tube of the at least one array of tubes communicating with apertures in the enclosure and the at least one array of tubes being positioned about an outer surface of the enclosure, portions of the enclosure having an effective length L.sub.2 between the inlet and the outlet of each of the tubes and the tubes having a length L.sub.1, where L.sub.1 >L.sub.2,wherein said non-uniform noise energy divides into two components at the inlet of each of the tubes of the at least one array of tubes, a first component of the non-uniform noise energy propagates through each of the tubes over the length L.sub.1 and a second component of the non-uniform noise energy propagates through the enclosure over the effective length L.sub.2 such that when the non-uniform noise energy exits the outlet of each of the tubes, the non-uniform noise energy is out-of-phase and recombines with the non-uniform noise energy propagating over the effective length L.sub.2 thus reducing the noise levels generated from the means for generating noise energy.