Journal of Occupational Health and Epidemiology

en Enhancing High-Frequency Bandwidth in MPP-Porous Material Composite Absorbers: A Numerical Simulation Approach for Optimal Parameter Selection Occupational Health Original Article <div style="text-align: justify;">Background: Porous absorbers are highly effective at attenuating high-frequency noise, yet they face inherent limitations, including reduced absorption at lower frequencies and vulnerability to environmental factors. Combining porous materials with Micro Perforated Panels (MPP) offers a solution but often sacrifices bandwidth. This study deals with optimizing parameters to extend the bandwidth toward higher frequencies, considering health concerns related to high-frequency noise exposure. Materials & Methods: This study used Finite Element Numerical Simulation (FEM) in COMSOL to model a porous material and MPP composite. It examined parameters like material thickness, air gap, hole diameter, panel thickness, MPP perforation percentage, and layer configurations. The goal was to find the best configuration to expand bandwidth, selecting and fixing the most effective parameter at each stage. Results: Findings from the simulated model aligned with direct impedance tube measurements. Enlargement of the fibrous material thickness, up to practical limits, expanded bandwidth. Optimizing MPP parameters involved minimizing hole diameter and panel thickness while maximizing perforations. The most effective layer configuration for bandwidth expansion consisted of an air layer, porous material, another air layer, additional porous material, and the MPP layer. Conclusions: Careful parameter selection can significantly increase bandwidth and absorption coefficients at higher frequencies. The incorporation of MPP enhances the composite's overall resilience, offering mechanical strength, resistance to environmental factors, and aesthetic appeal. The high precision of FEM simulations positions them as a valuable alternative to direct measurements such as impedance tube assessments. This study provides a comprehensive approach to improving porous absorber performance. </div> Porosity,Noise,Finite Element Analysis,Environmental Exposure, 119 131 http://johe.rums.ac.ir/browse.php?a_code=A-10-392-7&slc_lang=en&sid=1 Mohammad Javad Sheikhmozafari mj.sheikhmozafari@yahoo.com 22400319475328460010154 22400319475328460010154 No Ph.D. in Occupational Health Engineering, Dept. of Occupational Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. Tehran University of Medical Sciences Akbar Ahmadi Asour mj.sheikhmozafari@Gmail.com 22400319475328460010155 22400319475328460010155 Yes Assistant Prof., Dept. of occupational Health, School of Health, Sabzevar University of Medical Sciences, Sabzevar, Iran. Sabzevar University of Medical Sciences Sara Hajinejad Kurosh.sheikhmozafari@Gmail.com 22400319475328460010156 0009-0004-4639-4970 No M.Sc. in Occupational Health Engineering, Dept. of Occupational Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. Tehran University of Medical Sciences