Exothermic reaction zone

A third alternative has been proposed by Anderson and Brown (A6, A9) as an outgrowth of their research on the ignition of composite propellants. Their ignition studies suggest significant contributions to the overall combustion process from the solid phase. Two exothermic reaction zones contributing to combustion are considered, as shown schematically in Fig. 19. 

The heat transfer process in the combustion wave of TAGN consists of three zones, similar to what was illustrated for HMX in Fig. 5.5. Zone I is the solid phase, the temperature of which increases exponentially from the initial temperature, Tg, to the decomposition temperature, without chemical reaction. Zone II is the condensed phase, the temperature of which increases from T to the burning surface temperature, T, in an exothermic reaction. Zone III is the gas phase, the temperature of which increases rapidly from to the final combustion temperature, Tg, in an exothermic reaction. 

Cowperthwaite and Adams (Ref 10) show from details of the energy distribution in the reactive wave at various times, how the propagation bf a reactive shock depends on the flow conditions behind it. Soloukhin (Ref 9) conducted a study of the hydrodynamic structure of an exothermic reaction zone behind a nearly one-dimensional shock. Measurements were made in shock... 

Membranes coupling endo- and exothermic reaction zones (e.g., hydrogenation-dehydrogenation) Supported liquid membranes (SLM) for homogeneous catalytic processes... 

Experimentally, the moment of ignition is recorded according to the appearance of light emission or a rapid rise of the temperature in the oxidation zone. The ignition is considered established as soon as the combustion process becomes steady. Shortterm glow is regarded as a flash. In the steady-state combustion the heat flux from the exothermal reaction zone to the fresh polymer surface makes up for all the heat necessary for the self-sustaining reaction. 

Thermal frontal polymerization is a mode of converting monomer into polymer via a localized exothermic reaction zone that propagates through the coupling of thermal diffusion and the Arrhenius reaction kinetics of an exothermic polymerization. We review the range of nonlinear phenomena that have been observed in frontal polymerization systems and report new results on the role of gravity in spin modes and the development of spherically-propagating fronts. 

R.I. Soloukhin, Exothermic reaction zone in one-dimensional shock waves in gases. Combust. Explos. Shock Waves 2(3), 6-10 (1966)... 

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