Modeling the role of radicals in the ignition of and flame propagation in hydrogen-air and methane-air mixtures

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1984

OSTI ID:5634583

Wiriyawit, S

A model is developed for a transient, premixed, laminar flame in a closed one-dimensional adiabatic combustion chamber. The flame is ignited by a high-temperature plasma rich in H and OH radicals. Ignition and flame propagation are described by a numerical solution of the one-dimensional, compressible conservation equations for reactive flows. The numerical method makes use of a predictor-corrector method and an implicit Euler method to integrate the fluid dynamic and chemical kinetic parts respectively. Hydrogen-air and methane-air mixtures are selected as the reactive gases. The effects of the magnitude and the form of the ignition energy is explored. The energy is either totally thermal or partly thermal and partly in the form of radicals, H and OH. For the hydrogen-air mixture, the results show that energy supplied as OH radicals is a more efficient agent in igniting the mixture than thermal energy. An improvement in flame propagation and flame velocity is found only in the case where the OH radicals are allowed to spread out of the ignition source. For the methane-air mixtures, the results show that improvement in flame propagation and flame velocity is found in the case of plasma with high temperature and high radical concentrations. However, no improvement is found in the case where either OH or H radicals are allowed to spread out beyond the ignition source.

• OSTI ID: 5634583
• Country of Publication: United States
• Language: English

Related Subjects

08 HYDROGEN
080800* -- Hydrogen-- Properties & Composition
090110 -- Hydrocarbon Fuels-- Properties-- (1979-1989)
10 SYNTHETIC FUELS
ADIABATIC PROCESSES
AIR
ALKANES
BINARY MIXTURES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COMBUSTION
COMBUSTION CHAMBERS
DATA
DISPERSIONS
ELEMENTS
EXPERIMENTAL DATA
FLAME PROPAGATION
FLAMES
FLOW MODELS
FLUID FLOW
FLUIDS
GASES
HIGH TEMPERATURE
HYDROCARBONS
HYDROGEN
HYDROXYL RADICALS
IGNITION
INFORMATION
KINETICS
MATHEMATICAL MODELS
METHANE
MIXTURES
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
OXIDATION
QUANTITY RATIO
RADICALS
REACTION KINETICS
THERMOCHEMICAL PROCESSES
VELOCITY