Interface waves on a compliant coating bounded by a fluid flow, and their excitation by acoustic resonance

The stability of interface waves on a compliant coating, attached to a rigid substrate and exposed to a laminar or turbulent fluid flow, has been the subject of several theoretical studies, and of experimental investigations in which the onset and growth of instability waves was determined. Solutions of the characteristic equation of the problem have been obtained, which furnish dispersion curves and stability information for the interface waves, assuming a compressible fluid in order to attain the correct static limit. It is shown that the excitation of these interface waves by incident inhomogeneous acoustic signals can occur in a resonant fashion. Using this approach, an accurate experimental determination of the dispersion curves, of the onset of instability, and of the growth properties of interface waves appears to be possible.