Ejecta are small particles released from an intensely shocked material’s surface defects. The subsequent transportation and breakup, especially during the secondary breakup process, creates an interesting multiphysics problem which involves hydrodynamics, chemical reactions, and multiphase materials.
Description
Ejecta are small particles within an impulsively driven flow. Of importance to the research at FMECL is the study of ejecta that propagate from a material when the surface is rapidly accelerated, such as during an intense shock. In this case, a shock driven Richtmyer-Meshkov instability causes the initial ejecta release from the material, in which the shock wave interacts with the small imperfections on the surface of the material. Such shocks are often intense enough to cause some sort of melting of the material, creating a difficult multiphysics problem that involves the considerations of multiphase materials, hydrodynamics, heat and mass transfer, and chemical reactions.
Studies on ejecta are also found in volcanic explosions, astrophysics, respiratory events, and other high-energy applications.
Images
Velocity and temperature fields for a resolved simulation of solid particle shock acceleration. [1]
Further Reading
- Maxon, W. C., Nielsen, T., Denissen, N., Regele, J. D., and McFarland, J. (April 9, 2021). “A High Resolution Simulation of a Single Shock-Accelerated Particle.” ASME. J. Fluids Eng. July 2021; 143(7): 071403. https://doi.org/10.1115/1.4050007