平面扬声器激励矩形小室声场有限元数值分析

Sound Field Excited by Panel Loudspeaker Simulation and Analysis of Rectangular Small Enclosure with FEM

基于有限元方法,建立了平面扬声器与封闭矩形小室内空气的耦合模型,分别就小室内壁敷设吸声材料和平面扬声器安装位置对小室声场分布的影响进行了研究。结果表明:适当增加小室内壁的声吸收以增加简正波的带宽,使声场中各点声压响应曲线更加平坦,但是当吸声系数超过某一值时,继续增大声吸收对小室声场的均匀性改善并不明显;与点声源安装在矩形的角点上可以得到较均匀和较强的声场不同,当选用平面扬声器做声源时,则扬声器应尽量安装在矩形的中心位置。本结论对平面扬声器激励下封闭声场的设计具有指导意义。

Based on FEM, tile fluid - structure coupling model of panel loudspeaker and the interior air inclosed by rectan- gular small cavity are established. The influence on the sound field distribution at the condition of different sound - absorbing material glued on the inner surface of the cavity and different position panel hludspeaker fixed is studied. The conclusion is that increasing the acoustic energy absorption of the inner wall of the cavity appropriately could widen the bandwidth of nor- real frequency and flatten the SPL frenquency response curve at any point in the sound field. It is also shown that,if it is de- sired to excite relatively strong and homogeneous sound field, when panel hmdspeaker is to be used,it should be placed in the middle of the surface,unlike point sound source should be placed in the corner（junction of three surfaces）. The study will supply important clues for inclosed soundfield design which excited by pauel loudspeakers.