Mass Velocity Profiles for Non-Ideal Detonation of Mixtures of Nitromethane and Ammonium Perchlorate Overloaded with Aluminum. Measurements and Calculation

Abstract

Earlier, by comparing the results of mathematical modeling with experimental data on the non-ideal detonation velocities of triple mixtures of nitromethane and ammonium perchlorate with aluminum excess, the rates of exothermic reactions and the consumption degree of components within the detonation wave reaction zone were determined. A quasi-one-dimensional model of steady detonation was used for calculations, in which all components have a common pressure and move with a common mass velocity, and exothermic conversion is carried out in three stages, which include decomposition of nitromethane and ammonium perchlorate and diffusion combustion of aluminum. To confirm the obtained results and the applicability of the relatively simple theoretical model, calculations of the mass velocity profile during detonation of one of the triple mixtures with 17% nitromethane have been carried out. The calculation results are in agreement with the measured mass velocity profile, concerning the shape of the profile, the amplitude and the rate of decrease of the mass velocity along the detonation reaction zone. A possible explanation of a “leaning” of the beginning portion of the mass velocity profile observed in experiments has been proposed, and an estimate of the rise time of the sensor signal is given, taking into account the calculated curvature of the shock front of the detonation wave.