Converging Shocks in Water

Veronica Eliasson Postdoctoral Scholar GALCIT California Institute of Technology Pasadena, CA Fluid-solid interactions present a challenging and coupled problem. This presentation will focus on converging shocks in water confined in an elastic body. Both experiments and simulations will be considered. The overarching goal is to provide quantitative results for shock-focusing in a converging geometry in water, and provide a better understanding of the response of the surrounding material and how it affects the focusing event.
To create a converging shock in water, a projectile launched from a gas gun impacts on a liquid contained in a converging geometry. The impact on the liquid initiates a shock wave which, during the focusing phase, builds up high pressure. Consequently, the shock in the liquid transmits to the solid. As a result, the waves in the material are then influencing the wave propagation in the liquid, creating a coupled problem.
Simulations are performed with Overture(LLNL), a finite difference code with overlapping grids and adaptive mesh refinement. Three types of simulations are considered to help quantify the experimental data: simulations of converging shocks in water in a rigid confinement, simulations of wave propagation in the surrounding material, and simulations with a solid-liquid coupling using Euler equations for the fluid domain and linear elasticity equations in the solid domain.
Results have the potential to enhance the design of marine structures subjected to dynamic loading, as well as improve the techniques used to generate high-speed liquid jets. Schlieren photograph of the impact event taken with a 20ns spark source. --------------------------------------------------------------------------------Veronica Eliasson has been working as a postdoc at GALCIT, Caltech since Oct. 2007. She is working on a joint project with Prof. Paul Dimotakis and Prof. Ares Rosakis investigating converging shocks in water, where the liquid-solid coupling between the confined water and the surrounding material is of interest.

Location: Stauffer Science Lecture Hall, Rm 102

Audiences: Everyone Is Invited

Contact: April Mundy