不同泡沫镍基复层结构在低频区的吸声性能

摘要

探讨网状泡沫镍及其复合设计结构在声波低频区200~2000 Hz范围内的吸声性能.结果发现,对于孔隙率为89%,厚度为2.3 mm,平均孔径为0.57 mm的泡沫镍,1~5层泡沫体的吸声效果都很差.加入背后空腔和前置穿孔薄板都可提高吸声系数:5层叠加再加入5 mm厚的背腔,泡沫体的最大吸声系数在1000~1600 Hz内达到0.4左右;双层泡沫镍加入5 mm厚的背腔后,同时再在前面贴合一层穿孔薄板,泡沫体的吸声系数在1000 Hz左右时甚至达到了0.68.%Commercial 3D reticular nickel foam and its composite structure were investigated on the sound absorption at 200?2000 Hz. The absorption performance of foam plates 1?5 layers (1-layer thickness: 2.3 mm; porosity: 89%; average pore-diameter: 0.57 mm) was found to be poor, and could be improved by adding backed cavum or front perforated thin sheet. The absorption coefficient could reach about 0.4 at 1000?1600 Hz for the composite structure of 5-layer foam with a backed 5 mm-thick cavum, and even 0.68 at about 1000 Hz for that of 2-layer foam with the same cavum and a perforated plate closely in front of the foam.