耦合封闭声腔的主导声辐射模态确定方法

Determination method of dominant acoustic radiation modes in coupling enclosure

将在某一频率下或某一频段内对封闭声腔声势能起主要作用的一阶或几阶声辐射模态定义为耦合封闭声腔的主导声辐射模态。准确认定主导声辐射模态至关重要,直接影响有源控制效果。然而,现有的主导声辐射模态确定方法,要么仅考虑辐射效率的作用而忽视模态幅度的影响,要么就需要用到结构模态信息,难以实现工程应用。基于此,综合运用计算和测试手段,全面考虑辐射效率和模态幅度两个因素,提出了一种基于"初选—预留—后验"的主导声辐射模态确定方法,并通过实验研究证明了该方法的有效性和可行性。结果表明:提出的确定方法能够准确认定主导声辐射模态,确定过程中不需要用到辐射体的结构模态信息,可用于指导控制目标选取或重构封闭声腔声势能。

At a certain frequency or in a band,one or several acoustic radiation modes which make a major contribution to the acoustic potential energy are defined as DARMs (dominant acoustic radiation modes) of coupling enclosure. The determination of DARMs is of virtual importance,and it directly affects the effect of active structural acoustic control. However,the current determination methods either one-sidedly emphasize the effect of radiation efficiency while ignoring the impact of modal amplitude,or require the knowledge of structural modes which was difficult to be extracted in engineering applications. To overcome these problems,comprehensively by the means of computation and testing,and fully considering both radiation efficiency and modal amplitude,a method based on “primary election-reservation-posteriori correction” was proposed to determine DARMs in coupling enclosure,and an experimental research was performed to verify the effectiveness and feasibility of the proposed method. Results show that the proposed method can accurately identify DARMs and does not require the knowledge of structural modes throughout the process,so it can be used to guide the selection of control objective or reconstruct the acoustic potential energy of coupling enclosure.