Thermo-chemo-mechanically coupled cavity dynamics and the emergence of multi-phase bursts

Abstract

Understanding the dynamics induced by confined thermo-chemical processes occurring inside a solid medium is a fundamental problem of interest in several applications, such as hotspot formation and micro-explosions in energetic materials and laser-induced cavitation for energy focusing and material characterization. In recent years, advanced experimental capabilities have uncovered elusive behaviours in such systems, including temperature spikes that emerge at short timescales, and multi-phase explosions. By coupling the mechanics of the solid, the thermodynamics, and the chemical kinetics of the decomposition reactions, the theoretical model developed here explains and demonstrates these phenomena. The dimensionless response of the system is studied numerically and analytical expressions for the mechanical response limits are derived. These results should be useful in guiding future experiments and in explaining phenomena that may emerge at various length and timescales.