A Study of Detonation Evolution and Structure for a Model of Compressible Two-Phase Reactive Flow

A two-phase model of heterogeneous explosives, due to Baer and Nunziato, is examined computationally by a new numerical approach that is a modification of the standard Godunov scheme. The approach generates well-resolved and accurate solutions economically, and treats rationally the nozzling terms that render the otherwise hyperbolic model incapable of a conservative representation. A broad range of the parameter space is investigated and two possible structures of steady, planar detonations are identified, along with subregions of the parameter space where they exist. The transient processes subsequent to impact by a low-speed piston are studied in detail, for a variety of cases, to describe the transition from a compaction wave to one or the other of the two steady detonation waves. The findings are compared with existing computational results.