초록 ▼

An actively controlled acoustic treatment panel for suppressing noise in a gas turbine engine nacelle including a backsheet formed by a planar matrix of adjacent individually controllable elements, where each of the controllable elements has a transducer and a honeycomb cell enclosing the transducer

An actively controlled acoustic treatment panel for suppressing noise in a gas turbine engine nacelle including a backsheet formed by a planar matrix of adjacent individually controllable elements, where each of the controllable elements has a transducer and a honeycomb cell enclosing the transducer. A facesheet is also bonded to the controllable elements. A plurality of sensors are positioned within the acoustic treatment panel for sensing acoustic pressure of the noise propagated against the facesheet. A driver is provided for electrically driving each of the transducers to effect displacement thereof in a direction substantially perpendicular to the facesheet. Circuitry is also operatively connected to the pressure sensors and the driver for controlling velocity magnitude and phase of the transducers during displacement, wherein a resulting acoustic impedance at the facesheet achieves a desired acoustic impedance boundary condition at the nacelle. The transducer is further made up of an inner lamination layer, an outer lamination layer, and a piezoelectric membrane positioned between the inner and outer lamination layers, wherein a plurality of aligned openings are provided in the inner and outer lamination layers so that the piezoelectric membrane can be displaced either toward or away from the facesheet.

대표청구항 ▼

An actively controlled acoustic treatment panel for suppressing noise in a gas turbine engine nacelle, comprising: (a) a piezoelectric membrane; (b) a plurality of interconnected honeycomb members having a first end positioned adjacent a radially inner surface of said piezoelectric membrane and a se

An actively controlled acoustic treatment panel for suppressing noise in a gas turbine engine nacelle, comprising: (a) a piezoelectric membrane; (b) a plurality of interconnected honeycomb members having a first end positioned adjacent a radially inner surface of said piezoelectric membrane and a second end spaced from said first end to form a cavity between said piezoelectric membrane and said second honeycomb member end, wherein a circumferential matrix of adjacent individually controllable elements is formed within the boundary of each honeycomb member; (c) a facesheet bonded to said second end of said interconnected honeycomb members; (d) a plurality of sensors positioned within said acoustic treatment panel for sensing acoustic pressure of said noise propagated against said facesheet; (e) means for electrically driving each of said individually controllable elements to effect displacement in a direction substantially perpendicular to said facesheet; and (f) means operatively connected to said pressure sensors and said driving means for controlling velocity magnitude and phase of said individually controllable elements during displacement, wherein a resulting acoustic impedance at said facesheet achieves a desired acoustic impedance boundary condition at said nacelle.