Patent ID: 6201872
Filing Date: 2001-03-13
Classification: G10K

Abstract:
An active-control system for attenuating noise in a duct having a fluid flow comprising:an array of stators positioned axially within the duct having a longitudinal length;a first array of sound sources capable of generating spinning mode sound and positioned a distance upstream of a first plane defined by the upstream-most portion of the stators, relative to the fluid flow, the upstream distance being less than the longitudinal length of the stators;a second array of sound sources capable of generating spinning mode sound and positioned a distance downstream of a second plane defined by the downstream-most portion of the stators, relative to the fluid flow, the downstream distance being less than the longitudinal length of the stators; anda controller for causing the first and second arrays of sound sources to generate sound including spinning mode sound such that it cancels a portion of the noise within the fluid flow that passes through the stators.