Applications of front tracking to the simulation of shock refractions and unstable mixing

Abstract

This article discusses the structural aspects of a front tracking code that has been in long usage by the author and others. The front tracking method is a mixed Eulerian and Lagrangean method for the sharp resolution of distinct waves in a fluid dynamical system. Such issues as code modularity and generality are of critical importance in the construction of a working code. A division of functionality between static geometry, dynamic geometry and physics allows the construction of a general code that can be used in many separate applications. Important design features of the code include the ability to detect, identify, and resolve wave interactions. These features have allowed the front tracking code to develop into a useful scientific tool that is well adapted for the study of fluid-interface-dominated flows. Particular examples that are discussed include the gravitational acceleration of a fluid interface and the acceleration of a fluid interface by shock waves.