高声强双层穿孔结构的吸声计算

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

摘要:

对高声强下不同的穿孔结构非线性声阻抗模型进行比较，分析入射声压对穿孔吸声结构声阻抗的影响，并提出双层穿孔结构的改进传递矩阵法。不同声阻抗模型的实验和计算结果表明，入射声压级小于140 dB时，Park模型和Maa模型的计算结果与实验数据吻合良好；入射声压级为140 ~ 150 dB时，Laly模型的计算结果更接近实验结果。对于高声强下的双层及多层穿孔结构，在所提出的改进传递矩阵法中，根据传递矩阵计算得到各层板表面声压级，每层穿孔的声阻抗根据声压级和穿孔参数进行计算，进而得到总声阻抗。结果表明，入射声压级为120~150 dB时，双层穿孔结构的改进传递矩阵法计算结果与实验数据吻合良好。

关键词:降噪;吸声;双层穿孔结构;高声强;非线性声阻抗

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