Sound radiation from a fluid-loaded infinite plate with a patch

This paper focuses on the solution to the vibro-acoustic response of a line-driven fluid-loaded plate with an elastic patch acting as a distributed inhomogeneity. The patch affects the plate's sound radiation by adding extra loading to the driving force and by scattering structural waves. When the driving force is located beneath the patch, the extra loading reduces the plate's supersonic velocity response and sound radiation. At some frequencies, however, the constructive superposition of scattered structural waves and near-field waves by the driving force outweighs the effect of patch loading and results in an increased sound radiation power. When the patch is located away from the driving force, wave scattering phenomena dominates the plate vibration and subsequent sound radiation. By examining the effect of the length and location of the patch on the sound power, it is possible to relate the changes in the sound power to the changes in supersonic velocity spectrum and velocity distribution contributed by the trapped modes in the patched area and interference between the scattered waves by the patch and the near- and far-field structural waves directly generated by the driving force. © 2013 Acoustical Society of America.