Sound Absorption Calculation of Double-Layered Perforated Sound-Absorbing Structure at High Sound Intensity

Abstract:

Different nonlinear acoustic impedance models at high sound intensity are compared， and the influence of incident sound pressure on the acoustic impedance are investigated. An improved transfer matrix method is proposed to calculate the acoustic impedance of double-layered perforated panels. A comparison of the calculation by different nonlinear acoustic impedance models and experiment results at different incident sound pressure levels indicates that the results obtained by the Park model and the Maa model agree with the measurement results well when SPL is lower than 140 dB， while Laly model can get better results when SPL is 140–150 dB. For structure composed of double-layered or multi-layered perforated panels at high sound intensity， according to the improved transfer matrix method， the sound pressure level of each layer is calculated by transfer matrix， and acoustic impedance of each layer is calculated based on sound pressure level and perforation parameters. Results of double-layered perforated panels calculated by improved transfer matrix method coincide with measurement results for incident sound pressure level at 120–150 dB.

Key words:noise reduction;sound absorption;double-layered perforated panel;high sound intensity;nonlinear acoustic impedance