Acoustic components, propulsion system, noise reduction methods

Abstract

This invention relates to an acoustic liner, a propulsion system, and a noise reduction method. The acoustic liner comprises: a housing, a perforated plate on a first end face, a back plate on a second end face, the first end face, the second end face, and the wall of the housing defining a sound-absorbing chamber; a porous dielectric layer located inside the sound-absorbing chamber, dividing the sound-absorbing chamber into a first sound-absorbing chamber and a second sound-absorbing chamber; and a piezoelectric crystal connected to the porous dielectric layer, the piezoelectric crystal being deformable upon energization to cause deformation of the porous dielectric layer, thereby changing the volume ratio of the first sound-absorbing chamber to the second sound-absorbing chamber.

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