Accession Number : AD0843094

Title :   Photochemical Ignition of Gaseous Fuel-Oxidizer Mixtures at Subatmospheric Pressures.

Descriptive Note : Scientific rept. no. 1, 1 Mar 67-29 Feb 68,

Corporate Author : VITRO LABS WEST ORANGE NJ WEST ORANGE LAB

Personal Author(s) : Levy, M. E. ; Cerkanowicz, A. E. ; McAlevy, R. F., III

Report Date : JUN 1968

Pagination or Media Count : 112

Abstract : The initiation of chemical reactions in fuel-oxygen and fuel-air mixtures by photochemical means has been studied. Stoichiometric mixtures of methane-oxygen, methane-air, hydrogen-oxygen, and hydrogen-air at room temperature and at pressures from 30 to 600 torr were subjected to ultraviolet irradiation in the wavelength range from 1000 A to 2000 A. The following quantities were measured as a function of reactant mixture pressure: minimum irradiance required to induce photochemical ignition; reaction front propagation velocity; and photochemical ignition delay times. It is found that the primary photochemical reaction responsible for the reaction initiation process is the photodissociation of oxygen molecules. It is estimated that an atomic oxygen density in the range of 10 to the 14th to 10 to the 15th atoms/cc is required for the initiation of reactions. For the reactant mixtures studied, this density corresponds to from 1 to 10 oxygen atoms per 10 to the 5th oxygen molecules. (Author)

Descriptors :   (*JET ENGINE FUELS, IGNITION), CHEMICAL REACTIONS, DISSOCIATION, FREE RADICALS, ULTRAVIOLET RADIATION, PROPAGATION, IGNITION LAG, PHOTOLYSIS, OXIDIZERS, METHANE, AIR, HYDROGEN, OXYGEN, SUPERSONIC COMBUSTION RAMJET ENGINES.

Subject Categories : Combustion and Ignition
      Fuels

Distribution Statement : APPROVED FOR PUBLIC RELEASE