Nonlinear Interaction of Impulsive Acoustic/Hydrodynamic Sources and Natural Ocean Inhomogeneities

Phase II research will follow the most promising leads developed in Phase I, with the end goal of developing a viable physics-based model that can explain observations available to the Government. A dispersive focusing mechanism, supplemented by the theory of cylindrically-symmetric solitons, is the most promising mechanism identified in Phase I. Three related tasks will be performed: Detailed theoretical and numerical analysis of the process of linear dispersive focusing in cylindrical geometry. Formulation of correct non-linear solitary wave propagation equations in cylindrical coordinates, and theoretical and numerical analysis of the transition from linear to non-linear propagation. Modeling of the radar signature produced by the cylindrical wave packets propagating outward from the source. A weak shock mechanism was studied in Phase I, and some additional research related to this mechanism is proposed for Phase II. Two tasks are planned. Adaptation of the existing shock propagation model to a non-uniform environment. Laboratory measurements of the long-time effects of the Richtmyer-Meshkov instability at the air/water interface.