Accession Number : ADA189170

Title :   Evolution of a Localized Thermal Explosion in a Reactive Gas.

Descriptive Note : Final rept.,

Corporate Author : INSTITUTE FOR COMPUTER APPLICATIONS IN SCIENCE AND ENGINEERING HAMPTON VA

Personal Author(s) : Jackson, T L ; Kapila, A K ; Stewart, D S

PDF Url : ADA189170

Report Date : Jan 1987

Pagination or Media Count : 63

Abstract : Experimental observations of ignition in premixed gaseous reactants indicate that perfectly homogeneous initiation is practically unrealizable. Instead, combustion first sets in, as a rule, at small, discrete sites where inherent inhomogeneities cause chemical activity to proceed preferentially and lead to localized explosions. Combustion waves propagating away from these hot spots or reaction centers eventually envelope the remaining bulk. This study examines the spatial structure and temporal evolution of a hot spot for a model involving Arrhenius kinetics. The hot spot, characterized by peaks in pressure and temperature with little diminution in local density, is shown to have one of two possible self-similar structures. The analysis employs a combination of asymptotics and numerics, and terminates when pressure and temperature in the explosion have peaked.

Descriptors :   *COMBUSTION, *EXPLOSIONS, *HOT SPOTS, *REACTIVE GASES, CHEMICAL REACTIONS, DENSITY, HOMOGENEITY, IGNITION, MIXING, REACTANTS(CHEMISTRY), SITES, SPATIAL DISTRIBUTION, THERMAL PROPERTIES, WAVES, EXOTHERMIC REACTIONS, ARRHENIUS EQUATION, ASYMPTOTIC SERIES, REACTION KINETICS

Subject Categories : Physical Chemistry
      Thermodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE