微孔分布范围对穿孔板吸声性能的影响

根据渗入工艺加工微穿孔板吸声结构产生的微孔不规则分布的特点,研究了微孔不同分布范围的穿孔板的吸声特性。研究发现,随着微孔分布范围的逐渐缩小,穿孔板的共振频率逐渐向低频方向移动。随着穿孔分布范围的变化,微穿孔板的表面法向声阻变化不大,表面法向声抗相对较大。利用穿孔板理论对微孔不同分布范围的穿孔板的吸声特性进行模拟,发现穿孔板理论仅适用于微孔分布范围较大的穿孔板。通过分析穿孔板阻抗的作用,使其在微孔分布范围较小的情况下,也能模拟穿孔板的吸声性能。

Influence of Distribution of Pore on Sound Absorption Property of Perforated Panel

According to the pore irregular distribution characteristic of perforated panel manufactured by infiltration, the influence of distribution of pore on sound absorption property of perforated panel is investigated by impedance tube experiments. The results show that the sound absorption peaks move toward the low frequency region with the decreasing of the distribution of pore. The normalized surface resistance is observed to be changed little with the change of the distribution of pore. But the change of normalized surface reactance is larger relatively. The theory of perforated panel is used to simulate the sound absorption properties of different pore distribution perforated panel. It is found that the theory of perforated panel is suitable for the perforation of a larger distribution area and not suitable for perforation of a smaller distribution area. The theory of perforated panel is modified to simulate the sound absorption properties for the case of perforation of a smaller distribution area through the analysis for the perforation plate resistance and reactance role.