基于特性阻抗的半主动吸声研究

提出了一种新的半主动吸声方法,并设计了一种新的半主动吸声系统.该系统由一层吸声材料和可以移动的刚性板组成,调节刚性板与吸声材料之间的空腔深度,使得吸声材料的表面特性阻抗和空气的特性阻抗相匹配,从而使吸声系数达到最大.最后进行了实验,实验结果表明了在中低频平面声波入射时,采用本方法的吸声效果改进比较明显,但在高频平面声波入射时,采用本方法的吸声效果就不是很明显,此时吸声主要是依靠吸声材料被动吸声.

Research on Hybrid Absorption based on Characteristic Impedance

In this paper,a new hybrid absorption method is brought forward and a new hybrid absorption system is designed which is composted of a layer absorption material and movable rigid panel.The cavity depth between the rigid panel and absorption material is adjusted in order to make the surface characteristic impedance of the absorption material mathch the surface characteristic impedance of the air,so the absorption coefficient is the maximal.In the last,a experiment is carried out,the experiment result denotes that the absorption effect is smart in middle and low frequent and imperfect in high frequent for passive absorption is reigning.