Concept of the Spatial-Periodic Micro-Structures Excitation at the Energetic Materials Combustion and the Low-Frequency Non-Acoustic Instability Phenomena

摘要

Understanding of the mechanism of the low-frequency non-acoustic instability phenomena at the solid rocket propellants combustion - one of the most complicated problems in the solid propulsion physics. The burning process of each specific solid propellant can be characterized by the set of own frequencies of pulsations of the burning surface that appears in the critical burning conditions. Several theories have been proposed highlighting one or other process as the dominant mechanism, but a unifying theory is yet to emerge. The present work focuses on one of the critical events, namely the spatial-periodic micro-structures (SPMS) excitation in the evaporated energetic materials (EM) liquid-viscous layer (LVL). The low-frequency non-acoustic combustion instability phenomenon, the chuffing phenomenon and the accompanying physico-chemical effects have received a new explanation within the concept based on the data of optical visualization of the physico-chemical processes on the EM burning surface. This concept connected, mainly, with excitation of the synergetic dissipative SPMS in the thin LVL and on the EM burning surface. At heating from above in the thin LVL occurs the thermo-electric convection excitation, that induce cellular movement and formation of the synergetic SPMS. On the EM burning surface is observed the process of self-organizing of the dynamic dissipative synergetic SPMS into the torch macro-structures. Suggested mechanism opens possibilities for understanding the essence of the EM unstable combustion phenomena on the new qualitative level.