Validation of a Shell-Shedding Model for Reacting, Liquid Ejecta Particles

Results from ejecta experiments performed at Los Alamos National Laboratory show that liquid metal particles ejected from a shocked surface show vastly different behavior depending on whether their accepting medium is inert or reactive. Those ejected into an inert medium demonstrate an expected deceleration behavior with velocities which are monotonically decreasing at a near constant rate. On the other hand, those ejected into a reactive, hydrogen-based medium exhibit a staged deceleration phenomenon in recorded LDV data. A hypothesis is that the ejecta particles travelling in the reactive medium form a hydride shell and the presence of the shell leads to physical processes which cause the non-monotonic deceleration. The specific physical processes which control this phenomenon are mostly unknown and are of interest for accurate models for simulating the trajectories of the metal particles after ejection. This work describes the development of point-particle based models for the hydride shell meant to simulate shedding of small particles from the hydride shell surface along with any phase changes simultaneously occurring in the shell. A framework for coupling the mass and energy transfer of the shed particles to the surrounding fluid flow is also described before discussing ongoing model validation efforts against the liquid, reactive ejecta experimental data.