Predicting Mixing and Combustion in the Afterburn Stage of Air Blasts

condensed phase explosions of TNT and HMX will be studied using Large Eddy Simulations (LES) based on the unsteady, compressible, reacting, multi{species Navier{Stokes equations (NSE) with a Nobel{Abel thermal equation of state to gain further understanding of the physical processes involved in a condensed{phase explosion. The simulation results will be validated against the experiments. The analysis of the mixing and afterburning of TNT explosions in free air and near the ground indicated that the combustion region of detonation products and air is determined by the vorticity patterns, induced by the Richtmeyer { Meshkov instabilities that arise during the explosion. When explosive is detonated above ground, the ground aects the shock propagation, thereby changing the orientation of the vorticity, giving the afterburning a mushroom shape, however the mixing and combustion are found to follow the same principles as for the free air detonation.