Experiments and Modeling for Biocidal Effects of Explosives

This paper reports an experimental and modelling study of the biocidal effect of an energetic mixture which is detonated in a closed chamber containing an initial spore distribution. The resulting spore neutralization efficiency is recorded as a function of measured detonation and combustion performance. We also report the results of a range of numerical modelling studies carried out to aid the interpretation of these experiments and to guide future developments. We find that the current energetic mixture (aluminum powder which is shock dispersed by detonation of a central high explosive core) gives variable combustion efficiency. The Al powder ignites on impact with the walls. In the modelling we match the recorded quasi-static pressures in each experiment and compare predicted spore neutralization with measured values. Using a critical spore temperature for neutralization of 670 K gives a good match to the experiments. We report how neutralization efficiency varies with changes to this temperature. The coupled experimental and modelling approach allows us to suggest requirements for future biocidal energetic materials.