Defence Science Journal, V 0148, No 4, October 1998, pp. 379-402 (9 1998, DESlDOC REVIEW PAPER Surface Pyrolysis of High Energy Materials Luigi DeLuca, Maurizio Verri, Fabio Cozzi, and Giovanni Colombo Facolta di Ingegneria, Politecnico di Milano, 32 Piazza Leonardo da Vinci, 201 33 Milan, MI, Italy. ABSTRACT The Arrhenius zero-order phenomenological pyrolysis law, commonly used in conjunction with the Vieille ballistic law to study pressure-driven burning of energetic materials, is revisited. Motivated by experimental and theoretical work performed in 1984 in this Laboratory, a relationship among several interplaying parameters is found under steady-stateconditions. This relationship corresponds to the Jacobian of the pyrolysis sensitivity parameters used in the Zeldovich-Novozhilov approach. The Arrhenius pyrolysis is still expressed in terms of a global surface activation energy, but consistency with the experimental ballistic law may require an explicit pressure dependenceas well. This conclusion is supported by a variety of arguments drawn from different areas. The linear dependence of the pre-exponential factor on surface activation energy (known as kinetic compensation) is proved and extended to the pressureexponent, for any given experimental data set under steady burning. Experimental results are reported for about a dozen solid propellants of different nature. The effects of surface pyrolysis explicit pressuredependence,although modest on steady-state burning, are potentially far -reaching for unsteady regime and/or unstable burning. The paper is mainly focussed on pressure-driven burning and Arrhenius pyrolysis, but the implemented method is believed to apply in general. Thus, enforcing KTSS zero-order, phenomenological pyrolysis with the Vieille ballistic law yields similar results and requires an explicit pressuredependence.In case, the Zeldo\Lich ballistic law is enforced instead of the classical Viei!le law, no explicit pressure dependence is required. The unifying concept for these different trends is the pyrolysis Jacobian as a consistency requirement between the implemented steady pyrolysis and ballistic laws. Es 9lbp(Phig -Plow) r I-nr I-nr (Phig.. -Plow.. ) nr..El (l-nr..)+~ NOMENCLATURE a,b Nondimensional stability parameters '!pb£ Multiplicative factors As ,B s Multiplicative factors c Specific heat (caVg K) em A verage fitting error E(...) Activation energy (caVmole) E(.-) E(-) I m I T(...>, Nondimensional activation energy El Phig In Phig -Plow In Plow -(Phig-Plow) Is J k External radiant flux intensity (cal/cm2s) Running counter, integer ZN steady sensitivity parameter Received 18 March 1997. revised 05 November 1997 379