| This dissertation focuses on the interaction of shock wave with material interfaces in shock wave lithotrispsy (SWL) and inertial confinement fusion (ICF).;In the area of SWL, a method to characterize shock wave lithotripters by examining the potential for cavitation associated with the lithotripter shock wave (LSW) has been developed. The method uses the maximum radius achieved by a bubble subjected to a LSW as a representation of the cavitation potential for that region in the lithotripter. It is found that the maximum radius is determined by the work done on a bubble by the LSW. The method is used to characterize two reflectors: an ellipsoidal reflector and an ellipsoidal reflector with an insert. The results show that the use of an insert reduced the ---6 dB volume (with respect to peak positive pressure) from 1.6 cm3 to 0.4 cm3, the -6 dB volume (with respect to peak negative pressure) from 14.5 cm3 to 8.3 cm3, and reduced the volume characterized by high cavitation potential (i.e. regions characterized by bubbles with radii larger than 429 microm) from 103 cm3 to 26 cm3. Thus, the insert is an effective way to localize the potentially damaging effects of shock wave lithotripsy, and suggests an approach to optimize the shape of the reflector.;Also in the area of SWL, the dynamics of bubbles near a kidney stone subjected to a lithotripter shock wave are considered to address the effect of kidney stone geometry and composition on the cavitation potential near the stone in a shock wave lithotripter. Results of the reflection of the LSW from cylindrical kidney stones with proximal surfaces of varying geometry show that the presence of the stone enhances bubble growth near the stone and decreases growth further away, due to constructive and destructive interference, respectively. These effects hold true regardless of the shape and curvature of the face, and are strongest for stones with concave faces and higher reflection coefficients. An interesting consequence of the analysis is an elucidation of the mechanism for enhanced cavitation activity and creation of deep craters on the proximal side of a kidney stone, as have been observed in recent experiments.;In the area of ICF, high-order numerical simulations of the Richtmyer-Meshkov (RM) instability at sub-100 nm scales are performed in order to determine the effects of a finite density gradient, viscosity, and mass diffusion on the growth rate of a perturbed interface. The results show that the peak growth rate is determined by the post-shock Atwood number, initial perturbation amplitude, and the average of the pre- and post-shock growth rate reduction factors. The results also show that viscous effects become important at a scale smaller than previous thought, and that an appropriate Reynolds number for RM uses the peak growth rate and initial perturbation amplitude as the velocity and length scale, respectively. |
