基于阻抗模型的玻璃棉声学参数反演方法研究
Research on the inversion method for acoustic parameters of the glass wool based on impedance model
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摘要: 为了能准确获取玻璃棉材料的声学参数,文章对玻璃棉声学参数在不同阻抗模型下的声学参数进行了反演。采用了厚度分别为22 mm和44 mm的玻璃棉样本实测吸声曲线及各声学参数,选取四种常用阻抗模型,通过遗传算法(Genetic Algorithm,GA)对玻璃棉材料进行声学参数的反演,并选择反演效果最优的模型进行敏感性分析。比较各参数反演结果的误差比,并对比不同模型描述的吸声曲线与测试曲线的一致性,最后量化并比较Johnson-Champoux-Allard (JCA)模型中各参数对吸声系数的影响程度。研究表明,使用GA结合JCA模型或Johnson-Champoux-Allard-Lafarge (JCAL)模型反演的参数值与测试值误差较小;JCA模型适用于玻璃棉材料的声学参数反演,模型中流阻率和曲折度的敏感性较高,反演过程需保证其精确度。Abstract: In order to obtain an accurate inversion method for acoustic parameters of the glass wool materials, the inversion effects of acoustic parameters based on different impedance models of the glass wool are studied in this paper. Four commonly used impedance models are selected for the inversion of the acoustic parameters of glass wool materials performed by GA(Genetic Algorithm), the measured acoustic absorption curves and other acoustic parameters of the glass wool samples with thicknesses of 22 mm and 44 mm are used for comparison, and the model with the best inversion effect is selected for sensitivity analysis. The error ratios of each acoustic parameter are compared in the inversion results, and the agreement of the acoustic absorption curves described by the different models with the test curves is compared, and finally the influence degree of each parameter on the acoustic absorption coefficient in the JCA(Johnson-Champoux-Allard) model is quantified and compared. It is shown that the parameter values inversed by using GA combined with JCA model or JCAL(Johnson-Champoux-Allard-Lafarge) model have less error ratio to the test values; the JCA model is applicable to the inversion of the acoustic parameters of glass wool materials, and the sensitivity of the airflow resistivity and tortuosity in the model is high, so the inversion process must be accurate.