Detonation properties of the mixtures of tetranitromethane/methanol and tetranitromethane/nitrobenzene

Abstract

In this work, the reaction zone structure, stability of detonation waves and limits of detonation propagation in the mixtures of tetranitromethane/methanol and tetranitromethane/nitrobenzene depending on the diluent concentration, were studied by a VISAR laser interferometer with a nanosecond time resolution. In the experiments, a sharp change in the reaction zone at the concentration of diluents in the vicinity of stoichiometry is observed – the amplitude of von Neumann spike decreases significantly. This is due to an increase in the initial reaction rate, which leads to the decomposition of HE directly in the shock wave front. It was found that the addition of diluent resulted in an increase in the detonation velocity of the tetranitromethane/diluent mixture in the vicinity of the stoichiometric concentration (about 25% of methanol or nitrobenzene). In almost the entire concentration range, the detonation waves are stable with respect to the formation of the cellular structure of the front. At the same time, in the range of diluent concentration of 15-35%, a poor reproducibility of the amplitude values of the particle velocity from shot to shot is observed. This is probably due to the longitudinal instability of the detonation waves in the mixture.