Numerical simulation of sound absorption coefficient of wood perforated wall panel with uniform small geometric patterns

Abstract

Wood perforated wall panel with geometric pattern is a form of direct piercing carved wood panel (DPCWP). It has been extensively used as decoration element in Malay architecture especially in palaces, mosques, public building and some houses. The important aspect focused on this DPCWP is its ability to act as sound absorber. The sound absorption coefficient (SAC) an, of wood perforated wall panel with uniform and small geometric patterns at 1kHz to 4kHz frequency band shall be improved optimally through the contribution of perforation ratio and resonance frequencies. From previous findings, the hypothesis is that wood perforated wall panel with uniform small geometric patterns gives good sound absorption performance at 1kHz to 4kHz frequency region. Two patterns of DPCWP are designed using resonance frequency technique at 1/3 octave centre frequency from 1.6kHz to 5kHz with perforation ratio in the range of 35% to 40% and have been successfully investigated. Simulation process is carried out using BEASY acoustics software, which is an established numerical modelling tool for Boundary Element Method (BEM) works. Numerical modelling based on BEM has been widely used for engineering design and prediction. Results show that it has almost the same trend with those in previous results. However, at frequency 1kHz to 4kHz, an results show an increment to the higher an compared to the previous results which are show small an values at the same frequencies. The higher an phenomena at high frequencies shown by the best samples, S5 and S7 are due to resonance frequency inside the air column in DPCWP apertures. Noise reduction coefficients (NRC) calculated in the region of 0.75 to 0.95 prove that DPCWP with uniform and small geometric pattern able to act as good sound absorber. This finding allows DPCWP to be used as sound absorber more effectively mosques and other enclosed rooms.