Compacted meta-panel through inhomogeneous double layer micro perforated and coiled up space channels for a broadband sound absorption: FEM based optimization and experiments

In this study, a compact meta-panel is designed and optimized using inhomogeneous single and double-layer micro-perforated panels integrated with coiled up space channels to achieve broadband sound absorption. A hybrid series–parallel configuration of thin and ordinary micro-perforated panels is investigated through finite element simulations to generate multiple resonance mechanisms and enhance sound absorption over a wide frequency range. The results demonstrate that combining series–parallel arrangements with inhomogeneous integration of normal and space-coiling structures effectively extends absorption performance across low, mid, and high frequencies. A genetic algorithm optimization is employed to fine-tune key structural parameters and further improve overall sound absorption bandwidth efficiency. Experimental investigations on both unoptimized and optimized meta-panels confirm excellent broadband sound absorption characteristics, with the optimized design exhibiting superior performance and improved efficiency relative to its compact thickness. Impedance tube measurements validate the numerical predictions and highlight the effectiveness of the optimized configuration compared with existing sound absorption solutions. The proposed meta-panel offers a compact, high-performance alternative to conventional sound absorbing materials and is well suited for aerospace, civil, and transportation applications where space and weight constraints are critical. These findings contribute to the advancement of acoustic metamaterials and provide valuable insights for future research on ultra-broadband noise attenuation.