Accession Number : AD0835822

Title :   COMPOSITE SOLID PROPELLANT IGNITION MECHANISMS.

Descriptive Note : Final rept. 1 Apr 65-31 Mar 68,

Corporate Author : UNITED TECHNOLOGY CENTER SUNNYVALE CALIF RESEARCH AND ADVANCED TECHNOLOGY DEPT

Personal Author(s) : Shannon,Larry J.

Report Date : JUN 1968

Pagination or Media Count : 113

Abstract : The objective of this program was to provide further knowledge on the mechanism of composite propellant ignition. Systematic variations in the binder, oxidizer, oxidizer particle size and concentration, catalyst type, and reactivity at the oxidizer-fuel interface were used to assess the effect of compositional factors on propellant ignition under conductive and radiative heating. When ignition is accomplished by conductive heating from a doubly compressed stagnant gas (shock tube), formulation variables exhibit little influence on ignition times in the presence of oxygen. In the conductive heating mode, fuel vaporization followed by a gas-phase reaction is the probable ignition mechanism for propellants formulated with thermoplastic polymers. A heterogeneous oxidative reaction followed by a homogeneous gas-phase reaction is the likely sequence for propellants containing an elastomeric polymer. The only compositional variables found to have significant effect on radiant energy ignition characteristics were the binder type, oxidizer type, and solids loading level. It appears that the ignition mechanism is basically the same for all the test propellants with variations allowed to account for differences in ingredient decomposition rates, possible exothermic surface reactions, and surface structure characteristics. Viewed in total, the data on compositional variables strongly suggest that in the flux range of 15 to 100 cal/sq cm-sec the site of a principal reaction (or energy source) in the radiant ignition process is in the gas phase immediately adjacent to the propellant surface. (Author)

Descriptors :   (*SOLID ROCKET PROPELLANTS, *ROCKET IGNITERS), COMPOSITE PROPELLANTS, CONVECTION(HEAT TRANSFER), CONDUCTION(HEAT TRANSFER), SHOCK TUBES, POLYMERS, SOLID ROCKET PROPELLANT BINDERS, GAS FLOW, STAGNATION POINT, ARC HEATERS, IGNITION, IGNITION LAG, INTERIOR BALLISTICS, EQUATIONS OF STATE, PYROLYSIS, MATHEMATICAL MODELS

Subject Categories : Combustion and Ignition
      Solid Rocket Propellants

Distribution Statement : APPROVED FOR PUBLIC RELEASE