Aircraft cabin noise control with smart foam treatment on fuselage sidewall - Laboratory tests

Abstract

The development and testing of an aircraft sidewall treatment using a smart foam lining is discussed. Smart foam is an active /passive hybrid noise control approach and consists of a passive acoustic matrix with embedded active elements. In the first phase, laboratory experiments were conducted on a double-wall system to evaluate the acoustic performance of several passive and active configurations of smart foam actuators attached to the base panel. In the second series of tests, active control using smart foam actuators was implemented on a stiffened aircraft sidewall configured with a trim panel. A multi-input multi-output (MIMO) filtered-X feedforward controller with realistic reference sensors (e.g., accelerometers) was used to accomplish active control through the smart foam elements by minimizing the error signal provided by an array of error microphones. The active control through smart foam actuators improved the noise reduction of the sidewall in the low- to mid-frequency range (200-800 Hz).