Control Modeling of Flexible Wall Cavity Vibroacoustic Systems

Vibroacoustic modeling of an enclosure with flexible walls is discussed. The block-diagram modeling method is based on formulating the modal parameters of the cavity with rigid walls and the structure with no fluid interaction, i.e. in-vacuo. Having the uncoupled modal models, the rigid wall cavity and in-vacuo structural modal are coupled, “in modal domain”, in a feedback manner. In addition to being computationally efficient, this modeling technique offers a very convenient platform, especially in block diagram based modeling softwares such as Simulink, for synthesis and analysis of active sound control in vibroacoustic systems. It allows for easy access to acoustic (pressure) or structural (acceleration/strain) variables for feedback or feedforward control purposes using structural (force/moment) or acoustic (volume velocity) actuation.