Calculating Sound Absorption Coefficients of Sound-Absorbing Materials Using Flow Resistivity

Abstract

To minimize the calculation errors in the sound absorption coefficient resulting from inaccurate measurements of flow resistivity, a simple method for determining the sound absorption coefficient of sound-absorbing materials is proposed.Firstly, the sound absorption coefficients of a fibrous sound-absorbing material are measured at two different frequencies using the impedance tube method.Secondly, utilizing the empirical formulas for the wavenumber and acoustic impedance in the fibrous material, the flow resistivity and porosity of the sound-absorbing materials are calculated using the MATLAB cycle program.Thirdly, based on the values obtained through reverse calculations, the sound absorption coefficient, the real and the imaginary parts of the acoustic impedance of the sound-absorbing material at different frequencies are theoretically computed.Finally, the accuracy of these theoretical calculations is verified through experiments.The experimental results indicate that the calculated values are basically consistent with the measured values, demonstrating the feasibility and reliability of this method.

Keywords

sound-absorbing material / sound absorption coefficient / flow resistivity / acoustic impedance

References

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Funding

National Natural Science Foundation of China(51705545)