Flow Instability at Charge Boundary During Nitromethane/Polymethyl Methacrylate Detonation
V. M. Mochalova1, A. V. Utkin1, V. A. Sosikov1, S. I. Torunov1, D. Yu. Rapota1,2, A. V. Savchenko1, M. Yu. Shakula1,3, V. V. Vilkov1,2, S. A. Koldunov1
1Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka, Russia
2Lomonosov Moscow State University, Moscow, Russia
3Moscow Institute of Physics and Technology, Dolgoprudny, Russia
Keywords: detonation, critical diameter, detonation instability, nitromethane, PMMA, VISAR, high-speed camera
Abstract
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-shell boundary. A NANOGATE-22/16 high-speed eight-channel sixteen-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 unstable flow at the edge of the charge in the NM/PMMA mixture can be stabilized by adding amines or glass microspheres.
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