吸声系数管道脉冲法测量技术及其模型研究

Sound Absorption Measurement in a Circular Pipe Using Impulse Method and Its Model Research

在先前的研究基础上,利用管道脉冲法测量材料的吸声系数。从测量结果来看,在200Hz到6000Hz频率范围内,测量结果与B&K4206阻抗管法测得的数据具有很好的一致性;而在200Hz以下,较之阻抗管来讲,数据更为可靠。利用测得的试验数据建立中低频范围内材料的低频反射系数模型,用来表示材料的吸声系数,从而可以更好地研究材料的低频吸声效果。而且本方法采用单传声器法,测量装置简单,可用于吸声系数的现场测量。

Based on the preliminary work, absorption coefficient of the material was measured using impulse method in a circular pipe. It was found that the result is in good agreement with the data resulted from the method of B＆K4206 impedance tube in the frequency range from 200 to 6000 Hz. For the frequency below 200Hz, our result is more reliable in comparison with B＆K4206 method. Furthermore, a model for determination of reflection coefficient in the region of middle and low frequency was established using the experiment data. With this model, the absorption coefficient could be derived, and absorption ability of the material in low frequency region could be studied well. Meanwhile, equipment of the proposed method was quite simple since single microphone was needed for measurement. This method can be used for in-situ measurement of sound absorption coefficient.