二次余数扩散结构复合穿孔板扩散吸声研究

A study on diffusion and absorption properties of the quadratic residue diffuser structure composited with perforated plate

声学结构研究一直以来都是学术领域的研究热点。扩散吸声结构(Diffsorber)由于兼具扩散和吸声性能而具有很好的研究意义。本研究将具有良好扩散性能的二次余数扩散(Quedratic:residue diffusers,QRD)结构和具有良好共振吸声性能的穿孔板结构进行组合,依据标准AES-4id-2001对二次余数扩散结构及其与厚度为1 mm,穿孔率分别为3%,5%,8%的穿孔板复合后结构的扩散性能进行了实验研究,得到了相应的反射声能极坐标图和扩散系数。结果表明,复合结构在100 Hz至800 Hz的频率范围内仍具有良好的扩散性能;复合结构反射声能在穿孔板共振频率范围内有明显的下降(平均超过2 dB)。本研究可为扩散吸声结构的设计与研制提供依据。

Acoustic structure study always is the research interest of the academic area. Diffusion absorbing structure （Diffsorber） has good research value because it has both diffusion and sound absorption property. Quadratic residue diffusers （QRD） structure which had good diffusion property was combined with perforated plate which had good sound absorption property in this study. According to standard AES-4id-2001, the diffusion experiments were carried out to study QRD structure and ones composited with perforated-plates which had 1 mm-thickness and perforated percentage of 3%, 5%, 8% respectively. The polar coordinate diagrams and diffusion coefficients of different structures were derived and analyzed. Results showed that the composite structure still had good diffusion performance in the frequency range from 100 Hz to 800 Hz. The reflection sound energy of composite structure reduced obviously in the perforated plate resonance frequency range where there was about 2 dB reduction averagely. The study result can provide the reference for the design and development of diffsorber.