Accession Number:

AD0861320

Title:

Photochemical Ignition of Gaseous Fuel-Oxidizer Mixtures at Subatmospheric Pressures,

Descriptive Note:

Corporate Author:

VITRO LABS SILVER SPRING MD

Report Date:

1969-05-01

Pagination or Media Count:

57.0

Abstract:

Experimental results are presented on the radiative initiation of sustained combustion in unsensitized, stoichiometric mixtures of methane-oxygen, methane-air, hydrogen-oxygen and hydrogen-air at room temperature and at fuel-oxygen partial pressures from 25 to 600 torr. Minimum irradiance required to photochemically induce ignition, photochemical ignition delay time and reaction front propagation velocity were measured as a function of reactant mixture pressure. Delay times of 0.1 to 1.0 msec were measured for the photochemical initiation of sustained combustion under pressure-temperature conditions where thermal ignition does not occur. The primary initiation mechanism is shown to be photodissociation of oxygen by radiation in the Schumann-Runge continuum 1350-1700 A, a region still inaccessible to laser sources. Generation of a critical concentration of atomic oxygen is a necessary precondition for ignition. Because the initiation mechanism is found to be independent of fuel type, applications are suggested to many fuel-air systems of practical interest. Fundamentally, this unprecedented photochemical initiation of sustained combustion of unsensitized fuel-air mixtures represents a promising new departure in the field of combustion. Author

Subject Categories:

  • Combustion and Ignition
  • Jet and Gas Turbine Engines

Distribution Statement:

APPROVED FOR PUBLIC RELEASE