Modeling and analysis of a planar source based flexible micro-perforated panel absorption structure

In order to enhance the low frequency sound absorption performance and the applicability of the traditional micro-perforated absorbers under complicated noise environments, a composite sound absorption structure consisting of a front flexible micro-perforated panel (MPP), an air cavity and a back planar loudspeaker (PL) is proposed. In addition to the mid and high frequency sound absorption properties of the MPP, with a properly optimized exciting force on the planar loudspeaker, the composite absorber has the ability to absorb low frequency sound. The planar loudspeaker is treated as a plate driven by a controllable point force. The theoretic analytical model is set up by the modal expansion and vibro-acoustic coupling method. Then a Finite Element (FE)based acoustic simulation model of the proposed structure is established. Theoretical analysis and numerical simulations are carried out to validate the proposed model.