流场中填充吸声材料夹层板结构的声振耦合特性

Vibro-acoustic coupling characteristics of the sandwich structure with absorptive material in external convected fluids

采用等效流体模拟吸声材料,建立了外部流场作用下填充吸声材料夹层板结构的声振耦合模型,应用波动分析方法研究结构中声的透射特性,分析了入射声波入射角和方位角、流场流速和流向、夹层结构几何尺寸等参数对填充吸声材料夹层板结构声振耦合特性的影响。仿真计算表明吸声材料提高了双层板结构的隔声性能;隔声性能随着面板厚度和夹层厚度的增加而提高,随着入射角和方位角的增大而减小;在计算频段内（0-5000Hz）,逆流入射时传声损失随着马赫数的增大而减小,顺流入射时却随着马赫数的增大而增大。

An equivalent fluid model was employed to characterize the absorption of sound in the sound absorptive material. A vibro-acoustic coupling model was developed for the sound insulation of an sandwich structure filled with sound absorptive material in eonveeted fluids. The performance of sound transmission was analysed by employing the wave method. The analysed influential factors of vibro-acoustic responses include the incident angles and azimuch angles, the velocity and direction of convected flow and the geometrical dimensions of the double panels. The studies show that the insulation of the structure filled with absorptive material instead of air is improved ; the larger the thicknesses of the up and low panels and the gap are, the larger the sound transmission loss is; the larger the incident elevation angles and azimuch angles are, the smaller the sound transmission loss is ; in the calculation frequency band （ 0 - 5 000 Hz ）, the sound transmission loss decreases with the increase of Mach number when the sound is incident in the upstream but increases with the increase of Maeh number when the sound is incident in the downstream.