Computational studies of laser-driven flyer impact experiments to probe properties of inert and energetic materials

We present computational studies of experiments that measure the impact shock response in energetic materials on nanosecond-micrometer scales using a multi-material, arbitrary Lagrangian-Eulerian code, ALE3D. In the experiments, a laser launches an aluminum flyer-plate that impacts the energetic material. After impacting the energetic material, the output shock is detected by the motion imparted to a glass window. Experiments are also performed without energetic materials to focus on the flyer-plate drive conditions. Numerical results demonstrate agreement with experimental data for the laser-driven acceleration of the aluminum flyer and the first ∼5 ns after the flyer impacts the glass window. Our simulations indicate that we have to account for back-surface curvature in the flyer produced during the launch to give agreement with the experiment. Preliminary results are presented with an energetic liquid, nitromethane, using an equation-of-state and chemical kinetics model generated from the thermo-chemical code, Cheetah.