The two-mode waveguide formed by a rigid plane and an elastic plate

The structure of the acoustic field formed in the gap between a rigid plane and an elastic plate excited by a point force is considered. Special attention is given to the frequency range near the coincidence frequency in the case of the small values of the load parameter characterizing the plate loading with the medium. Expressions for the energy fluxes in the plate and in the gap are obtained, and the characteristic length of the energy transfer into the gap, as well as the degree of completeness of such a transfer, is determined.