複合層板吸音材料之聲場模擬與數值分析-台灣聲學學會.PDFVIP

‧ The Numerical Analysis and Simulation of Acoustic Field in Composite Sound-Absorbing Materials 1 2 2 1 2 2 1 2 804 70 07-5252000 Fax 07-5254299 E-mail skyang@mail.nsysu.edu.tw 50dB Abstract The light-weighted sound absorbing materials, that have low density and good bending strength of mechanical properties, are applied as sound insulation materials in practical noise control field. The path of sound propagation could be changed or isolated between the location of sound source and receiver due to its acoustic characteristics of sound absorbing material. To increase the transmission loss of sound absorbing material, it is designed as a composite layer of sandwich structure for industrial used. The reflected and transmitted sound pressure are calculated by the impedance method in this paper. The transmission loss is also evaluated for the multi-layer of composite sound absorbing material. Furthermore, the numerical simulation of acoustic field is studied by boundary element method (BEM) for a point source. The results show that the transmission loss is 50 dB for the designed sandwich structure of sound absorbing material. Keywords boundary element method, transmission loss, sound-absorbing materials 29 ‧ Source Path Receiver Active Noise Control Passive Noise Control