Instability of the Charge Boundary Flow in a Nitromethane/Polymethyl Methacrylate Detonation

Optical methods for recording fast processes are applied to study a flow behind a detonation wave front in a nitromethane/polymethyl methacrylate (NM/PMMA) mixture. It is shown that an increase in the PMMA concentration leads to an increase in the critical detonation diameter, which, as in pure NM, is determined by the occurrence of reaction failure waves at the charge–confinement boundary. A NANOGATE-22/16 high-speed 8-channel 16-frame electron-optical camera is used not only to properly study the spatial occurrence and propagation of reaction failure waves, but also to determine their characteristic size. It is shown that an unstable flow at the charge boundary in the NM/PMMA mixture can be stabilized by adding amines or glass microspheres.