Analysis of the influence of perforation angle to improve the performance of acoustic perforated panels

Abstract

Passive Noise Control (PNC) is the most commonly used method due to its ease and wide range of application. However, for noise that dominates at certain frequencies, it is necessary to modify PNC materials to achieve noise reduction at the desired frequency. One such modification is the use of perforated materials. With the correct configuration, it is possible to reduce noise at the desired (tunable) frequency. However, most perforations available in the market primarily focus on the perforation percentage. In fact, another factor that affects the performance of perforated materials is the length of the perforation neck. For relatively thin materials, the way to increase the length of the perforation neck is by drilling at a specific angle. Therefore, in this study, the design and simulation of perforated panels with hole angles of 0°, 10°,15°, and 20° were conducted. The design is a circular panel with a diameter of 100 mm and air gap of 10 mm. The parameters simulated are Sound Absorption (α) and particle velocity. Results show that the resonant frequency lower with the increasing perforation angle. Then sound absorption coefficient with 20° angle perforation is higher than the other. Furthermore, it can increase the sound absorption in lower frequency.