| An underwater explosion event has traditionally been viewed as two separate phases—a shockwave followed by an oscillating bubble. In this dissertation, the shockwave and bubble-oscillation phases of bubble motion are unified in a simple spherical model. For the shockwave phase, the bubble volume-acceleration is related to far-field pressures in order to both determine wall motion and provide initial conditions for the next phase. For the bubble-oscillation phase, new equations describing dilatational and translational motions are developed that include the effects of fluid compressibility, charge mass, and hydrodynamic drag. A portion of energy loss occurring in the oscillation phase due to phenomena associated with deformational motion is accounted for in the spherical model through the introduction of artificial reductions in the speed of sound, which yield model predictions that are in satisfactory agreement with experimental data. Small deformations of the bubble surface are examined through the formulation of an additional set of equations of motion for the oscillation phase that model dilatation, translation, and axisymmetric deformation with a global-shape-function representation of the surface. These equations demonstrate that translational motion has a substantial effect on bubble deformation; however, instability associated with deformational motion combined with limitations of the surface representation limits their utility. |
