Acoustic Radiation Damping of Vibrating Structures

Existing theories for predicting the acoustic radiation damping of structures are reviewed. A uniform pressure approximate theory for predicting the acoustic radiation damping of a single flexible panel, forming part of an otherwise rigid plane baffle, formulated by D. J. Mead [“The Effect of a Damping Compound on Jet Efflux Excited Vibrations,” Aircraft. Eng. 32, 374 (1960)], is developed into an exact theory, taking into account the nonuniform pressure distribution over a vibrating surface; a general expression is also developed to include any form of panel boundary support. The equations developed have been evaluated numerically by computer, for ease in predicting the acoustic damping factor for a wide range of panel sizes. The acoustic damping of a single panel forming part of a flat baffle and also of a cylindrical baffle has been measured experimentally by three methods.