DM&A perform hydrodynamic calculations independent of experimentally measured data, including complete numerical simulations of explosions in three dimensions involving complex interactions with rigid structures. Examples of specific numerical simulations are illustrated below.
A simulated nuclear explosion over a flat reflecting surface, made by placing a heated layer over the reflecting surface to model the effects of thermal radiation. The main effect of the surface heating is a precursor shock, seen here as a ramp-like structure running ahead of the expanding wave (lower right hand corner). The coloured regions represent different air densities.
A blast wave interacting with two structures. The heavy black lines are shock fronts and the lighter lines are contours of equal air density. From simulations like this it is learned that blast waves are often enhanced in unexpected ways as a result of interaction. A numerical simulation is a relatively inexpensive way to prepare for accidents, at an explosive storage site for example.
DM&A simulate explosions inside structures as well as outside, including small explosions like those often encountered in terrorist situations. Numerical simulation is also used to calculate the generic 'environmental enhancement' or 'E' factors used by the EBlast expert system.