Abstract:
This paper addresses the possible utilization of a highly concentrated pressure pulse caused by an implosion mechanism, as an underwater sound source. The operation principle and character of the uncontrolled implosion sound sources currently used in the underwater community, devices such as crushing light bulbs for sound propagation measurements and water guns for oil exploration, will be reviewed. Based on recent research efforts aimed at the understanding of the sonoluminescence phenomenon and a physical model for the collapse of a bubble, analytic results were employed to investigate the controllability of implosion for underwater sound generation. This includes the designing of an artificial cavity other than a sphere, initiating a shock wave and reshaping it for spherical convergence, manipulating the fluid--vapor composition in relation to the pulse signature, and assessing the conversion of hydrodynamic energy to acoustic energy. Some test data derived from prototype measurements in the laboratory and computer simulations will be used to discuss the feasibility of developing a simple, safe but controllable, implosion sound projector to meet practical needs in the underwater community.