Active control of low frequency sound absorption of large sized micro-perforated panel absorber by using point source

Structural acoustic controlled active micro-perforated panel absorber for improving wide-band low frequency sound absorption

“…Two control strategies are developed, i.e., impedance matching (IM) and pressure release (PR) strategy, which indirectly adjusts the surface impedance of the MPPA to match that of the air medium. Ma et al further expanded this work to large sized active MPPA, which demonstrated the feasibility of this approach in large sized case [35].…”

“…However, the performance of active sound absorption, the influence of the point force arrangement on control effect and physical mechanism of active control are not yet explored, which is of great importance for understanding physical nature of the SAC-AMPPA and carrying out structural optimization. Due to the complex vibration of the backing panel, the sound field in the cavity becomes complex and cannot longer be treated as the superposition of the incident and reflected plane wave as in Ref [32][33][34][35]. The corresponding physical nature will be different from the existing results.…”

“…The cone loudspeaker is used as the control element to realize the piston type source in Ref [32][33][34][35]. There is another way to implement the active MPPA, which uses a point forcecontrolled backing panel as the control source to form the SAC-AMPPA.…”

“…The influence of the secondary factor of MPP vibration to the sound absorption improvement in the control process is left for ongoing research. Then, the simplified modal analysis approach, similar to Ref [35] is used to establish the theoretical model. The remainder of this paper is organized as follows.…”

Exploring the acoustic potential of 3D printed micro-perforated panels: A comparative analysis

“…The effects of varying parameters such as pore diameter, perforation ratio, air cavity length, and specimen thickness on the performance of MPPs have been well-studied [ 13 ]. The pore diameter in MPPs plays a crucial role, and researchers have conducted comprehensive investigations into the performance of MPPs with varying pore diameters, including large-sized pores, ultra-micro pores, hybrid-arranged perforated panels, micro-lattices, and micro-perforated panels [ [14] , [15] , [16] , [17] , [18] ].…”