Recently fibreless solutions have become a trend in the design of sustainable and environmentally friendly duct silencers. In this respect microperforated panels have been proved to provide adequate performance for the substitution of unfavourable fibrous material layers commonly used in mass-produced silencers. This paper presents an acoustic study of microperforated elements aimed for effective and eco-friendly noise control solutions. Several microperforated sheet metal panels have been experimentally tested in a variety of layered configurations to maximize the sound absorption coefficient in the expected operational frequency range. The optimal solutions have been implemented in the design of novel fibreless solutions, presented in this research, and compared with typical fibrous material filled units commercially available. The results of the study demonstrate the appropriateness of the double-layered microperforates for a duct silencer application as well as for a variety of NVH (noise, vibration, and harshness) imple- mentations where potent noise absorption is aimed for.
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