Gas phase ignition theory for homogeneous propellants under shock tube conditions

An Asymptotic Analysis of Unsteady Diffusion Flames for Large Activation Energies

“…Closely analogous problems are the vaporization and boundary layer combustion of a flat plate of fuel in a stream of oxidizer, as considered by Libby and Economos (1963), Waldman et al (1969), Krishnamurty and Williams (1971), Kashiwagi and Summerfield (1973) and also the unsteady vaporization, ignition and combustion of a liquid or a solid in a stagnant reacting atmosphere, as treated by Waldman et al (1969), Strahle (1969), andHermance andKumar (1970).…”

Modeling of combustion and ignition of solid-propellant ingredients

“…Unlike the previous two categories, the gas-phase reaction models [199][200][201][202][203][204][205][206] presume that exothermic gas-phase reactions and their heat feedback to the propellant surface are the primary mechanism of ignition. Conservation of energy and species concentration in the gas phase is of major concern, but the condensed-phase equations are also included for completeness.…”

“…In the liquid, thermal decomposition and subsequent reactions, as well as phase transition, take place, generating gas Table 15 Theoretical models of solid-propellant ignition, adopted from Ref. [21] Solid-phase reaction model Heterogeneous reaction model Gas-phase reaction model [190][191][192][193][194][195][196][197][198] [199][200][201][202][203][204][205][206] Remarks Suitable for condensed-phase controlled materials, such as double-based propellants Suitable for gas-phase controlled material, such as low vulnerability ammunition (LOVA) propellants Effect of pressure is under-estimated since condensed-phase process is insensitive to pressure Suitable for the surface-reaction controlled material, such as polymers, hypergolic systems, etc.…”

Controlling mechanisms of ignition of solid fuel in a sudden-expansion combustor

“…The slopes of the curves with oxygen concentration greater than 20% are all about -2; hence, the ignition delay in the region of diffusion control depends upon the inverse square of the oxygen concentration, which is characteristic of ignition in the gaseous phase, consistent with the theoretical prediction of Hermance and Kumar. 15 The transition region was located where the oxygen concentration was between 15-20%. The ignition delay decreased with increasing concentration of oxygen in most experiments.…”