铝纤维板的复合结构吸声性能分析

摘要

为了解决变电站低频噪声问题,研制两种铝纤维板复合结构材料.首先基于阻抗管法分析铝纤维的面密度和空腔对低频吸声性能的影响,然后将铝纤维板分别与聚酯纤维、亥姆霍兹共振器进行组合形成复合结构材料,接着分析复合材料的低频吸声性能.结果表明,铝纤维的面密度对吸声系数影响较小,而增大空腔厚度可一定程度提高铝纤维板的低频吸声系数,但100 Hz处吸声系数仍然不理想;铝纤维板-聚酯纤维复合结构和铝纤维板-亥姆霍兹共振器复合结构相较于铝纤维板低频吸声性能均有很大的提高,特别是100 Hz的吸声系数最高可达到0.9以上,可用于变电站低频降噪.%To solve the problem of low frequency noise in substations, two kinds of aluminum fiber sheets are developed and studied. The influence of areal density and air cavity on low frequency sound absorption property of the aluminum fiber sheets is analyzed based on impedance tube method. The composite structures by combining the aluminum fiber sheets with polyester fibers and combining the aluminum fiber sheets with Helmholtz resonator are prepared respectively. And their low frequency sound absorption properties are studied and compared. The results show that the influence of the areal density on the sound absorption coefficient of the aluminum fiber sheets is small;the low frequency sound absorption coefficient of the aluminum fiber boards can be improved by increasing the cavity thickness, but the sound absorption coefficient at the frequency of 100 Hz is still low;Both the composite structure of the aluminum fiber sheets with polyester fibers and the composite structure of the aluminum fiber sheets with Helmholtz resonator have much better low frequency sound absorption property than the pure aluminum fiber sheets, especially at the frequency of 100 Hz, the sound absorption can reach 0.9 or even higher. So, they are feasible for low frequency noise reduction in substations.