Adiabatic Pyrolysis of Solid Propellants

Several one-step, irreversible, zero-order pyrolysis models (Arrhcnius, KTSS, and Merzhanov -Dubovitskii high activation energy pyrolysis), commonly used to study adiabatic burning of energetic materials with arbitrary pressure and initial temperature, are revisited. Motivated by experimental and theoretical work performed in 1984 by students of this laboratory, a relationship among the several interplaying parameters is found under steadystate conditions. This relationship corresponds to the Jacobian of the sensitivity parameters used inthe Zeldovich - Novozhilov approach. If the Vieille steady burn rate law is enforced, consistency requires an explicit pressure dependence for both Arrhenius and KTSS pyrolysis. But if the normal (or Zeldovich) steady burn rate is enforced, no explicit pressure dependence is required for both Arrhenius and KTSS pyrolysis. Other constraints arise for the Merzhanov - Dubovitskii pyrolysis model. The unifying concept for these different trends is the Jacobian consistency between the implemented steady pyrolysis and ballistic laws. The dependence of the pre-exponential factor on surface activation energy (known as kinetic compensation) is shown to be linear (Arrhenius) or almost linear (Merzhanov -Dubovitskii), for any given experimental data set under steady burning. Experimental results are reported for a variety of solid propellants of different nature.