A project is to be undertaken to further our understanding of linear stochastic wave fields, waves which have suffered sufficient randomizing scatterings or reflections as to lose most coherence. Such fields are present in applications of ultrasonics in many modern materials, and on sufficiently long time scales in most finite elastic bodies, in reverberation rooms for which the application is conventional acoustics, and in complex irregular structures for which accurate acoustics and vibrational descriptions have long been sought. The proposed project consists of two main thrusts. Laboratory and analytic work will be conducted on ultrasonic fields in strongly heterogeneous but statistically homogeneous media, which special emphasis on applications in ultrasonic nondestructive evaluation and on seeking the effects of residual coherence in such fields by demonstration the long-sought phenomenon of classical wave Anderson Localization. A second thrust consisting of large scale computational work on the responses of model reverberation rooms will also be conducted, with a view towards better understanding of eigenmode statistics with consequent potential impact on improved statistical models of the structural acoustics of complex systems.
