A fully viscous two-dimensional unsteady flow analysis applied to detonation transition in porous explosives

This report describes significant new progress towards solving the two-dimensional fully viscous unsteady flow in a reactive solid/gas mixture. The results demonstrate that it may be possible to predict whether a warhead with case failure (and filled with fragmented high explosive) will produce a low order detonation which is weaker than the one required to damage a structure. The loss of mass, momentum, and energy through a warhead case opening is a multi-dimensional problem even though the reaction front may progress axially through the damaged explosive. Mass is ejected in a basically radial direction and necessitates a multi-dimensional problem formulation in order to model the deflagration to detonation transition event accurately enough to make meaningful predictions. The appropriate equations of state and continuity equations are formulated and are solved by a finite differencing scheme. Run-up length to detonation in the fragmented explosive bed from a case opening through which mass is ejected should be married with a model of probabilistic case failure on impact to predict warhead lethality.