Sensitization of two-dimensional detonations in nitromethane by glass microballoons

Experimental results are reported on charge diameter effect and critical de tonation diameter of nitromethane (NM) gelled by 4 wt.% of PMMA and sensiti zed by thin-walled (1 mu m) monosize glass microballoons (GMB) of 47 mu m o r 102 mu m size at a constant mass fraction of glass (1%) in the mixture. T he dependence of the detonation velocity on the detonation shock-front tota l curvature at the explosive charge axis is presented for steel and PVC det onation tubes of various inner diameters. The predictive ability of the qua si-one-dimensional hydrodynamic model of detonation-reaction zone in GMB-se nsitized Nhl is improved by a better description of the hot spot growth sta ge. Dependencies of detonation velocity in NM sensitized by different GMBs on the charge diameter are calculated using available data on NM regression rate at detonation pressures and a reasonable agreement with experimental data is obtained. The effect of the confinement on the charge diameter effe ct as well as the dependence of the normal detonation velocity on the total detonation shock front curvature at the ci-large axis is also predicted by the model. However, there are still some difficulties in reproducing the e xperimental linear correlation between the critical detonation diameter of GMB-sensitized nitromethane and its reciprocal specific surface area.