Modifications of acoustic modes and coupling due to a leaning wall in a rectangular cavity

Acoustic modes and the coupling characteristics of a rectangular-like cavity with a slight geometrical distortion introduced through a leaning wall are investigated in this paper. A pressure variation index is proposed to quantify the global changes in acoustic modes caused by the inclination of the wall. Effects on the coupling between acoustic modes and structural modes are investigated using coupling coefficients. Numerical results show a simple relationship between the distortion effect and the acoustic wavelength. The effect is most significant when the distortion approaches the half wavelength. Compared with a rectangular enclosure, the existence of the leaning wall gives rise to a much more effective coupling between the structure and the enclosure.