Effects of general boundary conditions on vibro-acoustic responses of the panel-cavity system induced by a turbulent boundary layer

Abstract

This study proposes an analytical method for building a vibro-acoustic model of a panel-cavity system induced by a turbulent boundary layer (TBL) excitation, which is used to study the influences of boundary conditions on the vibro-acoustic responses of the system. In the theoretic model, the elastic restraints at the plate’s edges and the wall impedance of the cavity wall are considered at the same time. Based on the mode expansion, the vibro-acoustic response function of the vibro-acoustic model is built to present the coupling between the TBL and the system constructed by the panel and the cavity. Then, the model is validated by comparing it with the previous study, which shows good agreements. Finally, the effects of the boundary conditions, such as stiffness, damping, and impedance, on the mean quadratic velocity spectra and radiated sound power of the panel-cavity system are studied. It is demonstrated that the decrease of the boundary stiffness makes the radiated sound power of the panel drop above the frequency of the panel third mode. The boundary damping of the panel decreases the vibro-acoustic response of the panel-cavity system by working as an attenuation factor of the boundary. Furthermore, the increase of the radiated sound power with different wall impedances is due to the coupling between the structural mode of the panel and the acoustic mode of the cavity, or the resonance of acoustic mode in the vibration propagation direction.