Generation of acoustically bright and dark zone using multiple sources

Abstract

In this study, a method for the generation of acoustically bright and dark zone is proposed. The acoustical brightness and darkness of a zone is defined in terms of average acoustic potential energy of the zone[1]. The zones are assumed to be generated by multiple monopoles Two different kinds of cost functions are defined. The first kind is introduced to enhance the brightness of a zone, and the second kind is suggested to increase the contrast of two different zones. An eigenvalue analysis provides the optimal volume velocity distribution of the monopoles. As an extreme case, it is also shown that the optimal brightness solution approaches to the conventional focusing method when the bright zone shrinks to a point. 2-D simulation in free field is performed with varying bright zone size. The sources are distributed on the half sphere. The results show remarkable improvement in acoustical brightness and contrast.