Heterogeneous combustion takes place at the interface separating two different physical phases. The burning of solid propellants for rocket propulsion represents typically this type of combustion. So-called composite solid propellants are mixtures of finely ground salts, such as NH4ClO4 (ammonium Perchlorate = AP), and a polymer binder (for instance polybutadiene) in a ratio of order 4:1. At operational pressures combustion of AP-based solid propellants takes place in a thin zone close to the interface solid/gas. On the solid surface itself the polymer pyrolyzes forming gaseous products, and the AP decomposes into NH3 and HClO4 that react exothermically between themselves and with the polymer vapor in a diffusion flame. Details of the physics and chemistry of this type of combustion may be found elsewhere1-2. The purpose of this study is to present a mathematical model of the solid phase-gas system reacting at the interface, and to show that depending on the external variables (pressure, heat flux by radiation) and on the physico-chemical characteristics of the propellant (energy content, activation energies of the condensed phase decomposition reaction, etc.) burning occurs in different regimes.
Bifurcation in heterogeneous combustion
Riva G;
1984
Abstract
Heterogeneous combustion takes place at the interface separating two different physical phases. The burning of solid propellants for rocket propulsion represents typically this type of combustion. So-called composite solid propellants are mixtures of finely ground salts, such as NH4ClO4 (ammonium Perchlorate = AP), and a polymer binder (for instance polybutadiene) in a ratio of order 4:1. At operational pressures combustion of AP-based solid propellants takes place in a thin zone close to the interface solid/gas. On the solid surface itself the polymer pyrolyzes forming gaseous products, and the AP decomposes into NH3 and HClO4 that react exothermically between themselves and with the polymer vapor in a diffusion flame. Details of the physics and chemistry of this type of combustion may be found elsewhere1-2. The purpose of this study is to present a mathematical model of the solid phase-gas system reacting at the interface, and to show that depending on the external variables (pressure, heat flux by radiation) and on the physico-chemical characteristics of the propellant (energy content, activation energies of the condensed phase decomposition reaction, etc.) burning occurs in different regimes.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
