Vibroacoustic behaviour of a sound cavity enclosed by an acoustic black hole beam

In this paper, we propose a numerical approach to characterize the vibroacoustic coupling between a two-dimensional air cavity and an acoustic black hole (ABH) beam. Displacement variables expanded in terms of Gaussian basis functions are used for both the fluid and the solid, and the coupling condition at the interface between the beam and the cavity is imposed following the null space method (NSM). The approach turns out to be free of numerical instabilities. Concerning the simulations, it is shown that the noise inside the cavity is significantly reduced when the excitation is exerted on the ABH beam as compared to a uniform one. However, if a sound source is placed inside the cavity, no significant noise reduction is achieved by coupling the cavity to an ABH beam instead of a uniform one.