Optimization and Comparative Analysis of micro-perforated panel sound absorbers: A study on structures and performance enhancement

In this study three MPP (micro-perforated panels) absorber configurations (simple, series, parallel) were investigated via the response surface method (RSM) to broaden the absorption bandwidth. The study focused on the average normal sound absorption coefficient (SAC) in the range of 125–3000 Hz via impedance tube. The impedance tube results were finally compared with the Finite Element Method (FEM) and Equivalent Circuit Method (ECM) simulations. Samples Fabrication involves 3D printing, with optimized configurations exhibiting expanded absorption bandwidths. The average absorption coefficient was 1.5 times higher in series MPPs and 1.2 times higher in single and parallel MPPs compared to the non-optimal state. In the optimal state the series and parallel structures outperform the single design, and among the studied factors the hole diameter significantly influenced sound absorption more than others. The alignment of coefficients from various methods with RSM predictions was noteworthy. The results obtained from the FEM and ECM methods align perfectly, displaying a resonance peak at a frequency of 1380 with a value of 0.8. Below 1500 Hz, the laboratory method yields higher values than the numerical and theoretical methods. At higher frequencies, it aligns closely with the predictive methods. This study underscores RSM's effectiveness, demonstrating optimization benefits and coherence between numerical, theoretical, and experimental models in evaluating MPP absorbers.