复杂封闭空间结构声辐射的有源消声机制

采用两种控制目标函数,通过比较控制前后两个弹性板及空腔内声压模态坐标幅值与相角的变化,分析了复杂封闭空间结构声辐射的有源消声机制.结果表明,在一般情况下,空腔内噪声的降低是由两个弹性板的模态重组来实现;当扰动频率为顶板的一个固有频率时,有源消声则由顶板模态幅值抑制和底板模态重组的共同作用来完成.

Active control mechanism of structure-borne noise in an irregular enclosure

The active control mechanism of the structure-borne noise within an irregular enclosure is analyzed by comparing the variations of the amplitudes and the phases of the modal coordinates of two panels and interior sound pressure before and after control with two control performance functions. Results obtained demonstrate that at most disturbance frequencies, the sound pressure level within the enclosure is reduced by rearranging the modes of the two panels. When the disturbance frequency is merely one of the natural frequencies of panel a, the control voltage is applied to reduce the dominant mode of panel a and to adjust the mode arrangement of panel b respectively with the result of the decrease of sound pressure level within the enclosure.