Spatial attenuation of sound in a rectangular enclosure under active control of sound transmission through an elastically supported flexible panel

The present research involved a numerical analysis of the influence of the rotational and translational flexibilities of sound-transmitting panel edges in a two-dimensional cavity-panel system on the transmitted sound field under active control. We considered full coupling between the panel and the enclosed acoustic space. Visualisation of the sound field and a normalised impedance-mobility approach were used to investigate the performances of global and local control of the enclosed sound field and to overcome the limitations involved in assessing the attenuation of acoustic potential energy. The present results suggest that the optimal global control of the enclosed sound field is not attained under potential energy control. Good global and local performance is obtained using an acoustic control source at high eigen-frequencies. In terms of global and local performance, a high degree of translational flexibility of the panel edge yields better active control that a high degree of rotational flexibility.