吸声系数的传递函数法仿真计算

Simulative calculation of sound absorption coefficient by transfer function method

为得到吸声材料的吸声系数,提出了一种基于Virtual.Lab Acoustics平台的阻抗管模拟方法,建立阻抗管和试件的声学模型,提取声学计算得到的传声器测点处的复声压,然后基于传声器间距、传声器与试件距离,得到传声器测点位置的传递函数及吸声系数。将该方法的计算结果与文献值进行对比,验证了文中传递函数及吸声系数计算方法的正确性。通过仿真分析了阻抗管直径、传声器测点位置对计算吸声系数的影响,说明传声器测点位置可极大影响计算的吸声系数。对阻抗管内试件倾斜角度、试件厚度和试件后侧空气柱等对吸声系数的影响进行了定量计算。

In order to obtain the sound absorption coefficient of sound absorption material,a simulation method of impedance tube based on Virtual.Lab Acoustics platform is proposed.The acoustic model of impedance tube and specimen is established,and the complex sound pressure at the measured point of microphone is extracted.Then,the transfer function and sound absorption coefficient at the measured point of microphone are obtained based on the distance between microphone and the distance between microphone and specimen.By comparing the calculated results with those in literature,the correctness of the transfer function and the calculation method of sound absorption coefficient in this paper are verified.The influence of impedance tube diameter and microphone location on the calculation of sound absorption coefficient is analyzed by simulation.It is shown that the location of microphone measurement point can affect the calculation of sound absorption coefficient,and the acoustic modes in the impedance tube should be considered for the measurement point arrangement.Quantitative calculations are made for the influences of the specimen tilt angle,specimen thickness and the rear air column of the specimen in the impedance tube on the sound absorption coefficient.