Synergistic Noise Control Achieved by Parallel Integration of Micro-Perforated Panel and Helmholtz Resonator at High Ventilation Diameter Ratio

Abstract— Facilities within industrial production environments, such as air conditioning units, cooling systems, pumps, and compressors generate substantial broadband noise and harmonic noise. Broadband noise originates from air flow, whilst harmonic noise arises from rotational motion at specific frequencies. The primary objective of this research is to mitigate noise issues whilst maintaining favorable airflow characteristics. This study designed an acoustic attenuation structure based on the parallel principle of Helmholtz resonator and micro-perforated panel. This achieved synergistic noise reduction for both harmonic and broadband noise at a high inner-to-outer diameter ratio. A theoretical model was established using the transfer matrix method to predict the acoustic performance of the structure. A prototype model was fabricated using 3D printing technology, and its performance and model’ validity were experimentally verified. By adjusting the structural parameters, synergistic reduction of both broadband and harmonic noise can be achieved, rendering the design suitable for diverse industrial applications.