弹性结构封闭空间有源消声

Active noise control within enclosed space surrounded by flexible structure

College Of Marine Engineering, North western Polytecnical University Xi'an, 710072

摘要: 本文研究了外力激励弹性结构条件下封闭空间有源消声问题。首先根据声弹性理论,提出分步代入法求解初、次级声场,然后以矩形空间为例,研究了不同介质条件下有源消声规律。结果表明:对于弹性结构封闭空间有源消声,当结构一声腔耦合较弱时,次级声源基本上只能抵消声腔模态;当结构一声腔耦合较强时,次级声源不仅能抵消声腔模态,而且对抵消与声腔模态耦合良好的结构模态辐射声也有作用。最后,以有限长圆柱封闭空间为模型,完成了结构受点力激励,腔内为空气介质和水介质条件下的单次级声源有源消声实验。验证了理论结果。

Abstract: In this paper, a theoretical study on active control of noise in the enclosure surrounded by a flexible rectangular structure is accomplished. And then, under the conditions of a point force exciting structure filled up with air and water respectively, active control of sound field within finite length cylindrical enclosure is investigated experimentally by use of a single secondary source.
The theoretical and experimental results show that for the case of weak structural-cavity coupling onlythe cavity-dominated modes can be controlled effectively, both the cavity-dominated modes and a part of the structrure-dominated modes can be controlled if the structural-cavity coupling turns strong.