Sound radiation from a plate immersed in water near the free surface

The results on the acoustic response of a heavy fluid-loaded baffled plate excited by a harmonic point force are presented. The displacements of the fluid-loaded plate are decomposed on the basis of the in-vacuo plate modes and the radiated acousic waves are determined solving the Helmholtz equation in a fluid. The Green's function for the acoustic waveguide domain formed by the baffled plate and the free surface is modelled by the source-image method. Predictions for the radiated sound power from the plate and pressure spectra are calculated for varying depths of the free surface and compared against results from an unbounded domain to infer the effect of the free surface on the acoustic response of the plate. The proposed analytical model is verified by comparison with finite element simulations