Noise Reduction of Three Dimensional Enclosed Sound Fields Using Nonlinear Compensation

摘要

In this paper, the feasibility of implementing a nonlinear compensator technique in reducing noise transmitted into a three dimensional enclosure through a flexible panel is presented. A spherical wave, which is generated by a noise source located in the near field, is transmitted into a rectangular enclosure through a flexible panel. Piezoelectric patches, which are bonded symmetrically to the top and bottom surfaces of the panel, are used as actuators. The analytic model used here accounts for panel interactions with both the external and enclosed sound fields and the bonded piezoelectric patches, and this feature makes it appealing for a broad field of model-based active, passive, and hybrid noise control schemes. The nonlinear compensation scheme aims to increase the damping of the flexible panel linearly with the panel vibration amplitude and, thus, attenuates noise fields associated with structural resonance frequencies. Simulation results show that, despite the simple structure of the nonlinear compensator, high attenuation levels could be achieved. Results also show that the control input of the nonlinear compensation scheme is reduced, when compared to optimal control schemes.