基于FP通道-泡沫铝板复合结构的低频宽带吸声体

Low frequency broadband sound absorber based on FP channel-foamed aluminum plate composite structure

提出了FP(Fabry-Pérot)通道和泡沫铝的亚波长复合吸声结构,兼顾低频和宽带的良好吸声,平均吸声系数达90%。建立了该复合吸声结构的压力-热黏性声学有限元数值分析模型,阻抗管试验结果验证了从设计的截止频率366 Hz开始具有良好的吸声特性;基于有限元分析方法,讨论了FP通道的截止频率公比、吸声面积比、通道数量和泡沫铝板厚度对吸声性能的影响,并与其他复合结构进行吸声性能对比。结果表明,该复合吸声结构在噪声控制领域中有应用价值。

Here,the Fabry-Pérot(FP)channel-foamed aluminum plate subwavelength composite sound absorption structure was proposed considering simultaneously sound absorption of low frequency and broadband,its average sound absorption coefficient could reach 90%.The pressure-thermal viscosity acoustic finite element(FE)numerical analysis model of the composite sound absorbing structure was established,and the impedance tube test results verified that the proposed composite structure’s good sound absorption characteristics start from the designed cut-off frequency 366 Hz.Based on the FE analysis method,effects of FP channel cut-off frequency common ratio,sound absorption area ratio,number of channels and thickness of foamed aluminum sheet on the proposed structure’s sound absorption performance were discussed,and its sound absorption performance was compared with those of other composite structures.The results showed that the proposed composite sound absorption structure has a certain application value in noise control field.