摘要
提出了在随机声波入射下,基于倒频谱分析的测量吸声系数的一种新方法。在被测的系数材料的近前方放置一个麦克风,在随机声波入射下,该麦克风检测出麦克风处的声压,将此声压变换成倒频谱,再与入射声压的倒频谱对比,得到被测吸声材料表面的反射系数,从而得到该吸声材料的吸声系数。最后进行了实验,首先研究了麦克风距离吸声材料表面之间的距离与测得的吸声系数的关系;然后,研究了麦克风放置的位置以及被测吸声材料的面积与测得的吸声系数的关系;最后,对不同的吸声材料进行了实验。实验结果表明,在随机声波入射下,用该方法测量吸声系数是方便可行的。
Absorption coefficient is an important absorption function of the absorption material,traditional measurement methods of which are standing wave tube and other measurement methods,which have some shortcomings.A new measurement method of absorption coefficient by the use of cepstrum is theoretically and experimentally studied.Firstly,a suitable distance between the microphone and the absorption material is selected.Then,the effects of the size of the absorption material and the position of the microphone on the measured results are discussed.Finally,the absorption coefficient of the different absorption materials is studied.The experimental results indicate that the method used to measure the absorption coefficient is correct and practical.
出处
《机械设计与制造》
北大核心
2011年第2期196-198,共3页
Machinery Design & Manufacture
关键词
吸声系数
反射系数
倒频谱
驻波管
Absorption coefficient
Reflection coefficient
Cepstrum analysis
Standing wave tube
