Burning rate chemical kinetic effects

Even when the reaction rate at the surface is effectively infinite, chemical kinetics in the gas can influence the carbon-burning rate. Equation (28) requires that residence times in the gas are short enough to prevent chemical depletion of O2 from occurring before oxygen reaches the solid surface. At sufficiently high temperatures—for example, above about 3500K—a substantial amount of dissociation of O2 may occur [39] O atoms are appreciably more reactive than O2 molecules on carbon surfaces... 

With laser augmentation at 1 atm, HMX will exhibit a dark zone temperature plateau similar to NC/NG at 1300 to 1500 K. In this case, the single-step gas reaction can be applied to the primary flame the secondary flame will have no appreciable effect on steady burning rate, as in NC/NG. If it is desired to simulate the secondary flame, a more complex kinetic mechanism (at least two-step) must be considered. Complex chemical kinetics models have shown the ability to simulate the two-stage gas flame structure of RDX under laser irradiation. (However, complex chemistry models still have difficulty in predicting the correct temperature sensitivity of HMX, as noted below.)... 

S.A. Shackelford, B.B. Goshgarian, R.D. Chapman, R.E. Askins, D.A. Flanigan, R.N. Rogers, "Deuterium Isotope Effects during HMX Combustion Chemical Kinetic Burn Rate Control Mechanism Verified", Prop.. Exolos.. Pvrotech.. 14, 93-102 (1989). 

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