Transition from combustion to detonation in porous explosives

Burning to detonation transition in porous beds of a high-energy propellant

“…The data in Figure 8 from the shredded (and possibly the granular) VLU charges indicate that if there is a minimum in the z-% TMD curve it is very shallow; this too was the case for (granular) 20 um tetryl' 2 and the granular 15 pm AP mixtures studied by Korotkov et al 3 Consequently at high confinement, porous charges of VLU exhibit many similarities in DDT behavior to porous charges"of tetryl and somewhat similar behavior to some AP mixtures. In the case of tetryl, erratic resqonse of the earlier IPs resulted in values of Ato (relative time to detonation with respect to a specified x value) from which no smooth trend was evident.…”

“…1 , 3 For these composite mixtures, a differ'nt dependence of predetonation column length (z) on density was observed.…”

Analysis of deflagration to detonation transition in high-energy solid propellants

“…This is illustrated in Fig. 5 [36] show that when a granular bed has a high initial gas porosity (i.e., go-0.5 5), DDT, does not occur*…”

DDT Behavior of Ground Tetryl and Picric Acid

“…That too was the case in the reported PETN data 4 . But the two U shaped curves for PETN overlapped in some sections whereas the curves for fine and coarse tetryl do not intersect.…”