Performance of Vibro-acoustic Coupling of the Sandwich Structure with Absorptive Material and Cavity in External Convected Fluids

doi:10.3901/JME.2016.05.177

Abstract

Abstract: 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.

Key words: absorptive material, equivalent fluid model, sandwich structure, standing-wave attenuation frequency, standing-wave resonance frequency

CLC Number:

TB535

NING Shaowu, SHI Zhiyu, LI Xiaosong. Performance of Vibro-acoustic Coupling of the Sandwich Structure with Absorptive Material and Cavity in External Convected Fluids[J]. Journal of Mechanical Engineering, 2016, 52(5): 177-184.

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