采用等效流体模拟吸声材料,建立外部流场作用下填充吸声材料夹层板结构与封闭空间声场的声振耦合模型,应用波动分析方法研究结构的声透射性能,分析入射声波入射角和方位角、流场流速和流向、夹层板几何尺寸和声腔深度等参数对填充吸声材料夹层板结构声振耦合特性的影响。计算分析表明吸声材料提高了结构的隔声性能;结构的隔声性能随着面板厚度和夹层厚度的增加而提高,且“板-等效流体-板”共振频率向低频移动;随着入射角、方位角、马赫数和空腔深度的变化改变了结构的隔声性能,驻波衰减频率和驻波共振频率随入射角和方位角的增大向高频移动,随空腔深度的增加向低频移动,顺流入射时随马赫数的增加向低频移动,而逆流入射时则移向高频。
An equivalent fluid model is employed to characterize the absorption of sound in the sound absorptive material. A vibro-acoustic coupling model of the sandwich structure with absorptive material and cavity in convected fluids is developed. The performance of sound transmission is obtained by employing the wave approach. The effects factors of vibro-acoustic responses which were researched include incident elevation angles and azimuch angles, the velocity and direction of convected flow, the geometrical dimensions of the double panels and the depth of the cavity. Studies have shown that the insulation of an structure with absorption than air is improved; sound transmission loss increases with the thickness of the up and low panel and the gap increase and the panel- equivalent fluid-panel resonance shift to lower frequencies; the parametric variation of incident elevation angles and azimuch angles, Mach number and the depth of the cavity changed the performance of sound Transmission of the structure; standing-wave attenuation frequency and standing-wave resonance frequency shift to higher frequencies with the increasing of incident angles and azimuch angles and lower frequencies with the increasing of the depth of the cavity; standing-wave attenuation frequency and standing-wave resonance frequency shift to lower frequencies with the increase of Mach number when the sound is incident in the downstream but shift to higher frequencies with the increase of Mach number when the sound is incident in the upstream.
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