An experimental and computational study on the propagation and kinetic structure of laminar premixed flames

Thesis/Dissertation · Mon Jan 01 04:00:00 EST 1990

OSTI ID:5563664

Egolfopoulos, F

The steady propagation and chemical kinetic structure of adiabatic planar, laminar premixed flames were experimentally and numerically studied with systematic and extensive variations of the effects of fuel, oxidizer, pressure, stoichiometry, and flame temperature. Experimentally, the laminar flame speeds were determined by using the counterflow twin-flame configuration with laser Doppler velocimetry probing and systematic elimination of flame stretch effects. Numerical simulation was conducted by using validated hydro and transport codes together with various detailed chemical kinetic mechanisms. The parameter matrix of investigation included: (1) H{sub 2}, CO, CH{sub 4}, all C{sub 2}-hydrocarbons, and C{sub 3}H{sub 8} as fuels; (2) He, Ar, N{sub 2}, and CO{sub 2} as inert diluents; (3) pressure variations from 0.2 to 4.5 atmospheres; (4) stoichiometry from very fuel lean to very fuel rich; and (5) flame temperature from 1550 to 2250 K varied independently of stoichiometry. An independent study of the phenomena of flammability limits was conducted. Experimentally, limits of propagation of unstretched flames were determined by first measuring the extinction limits of stretched, counterflow flames and extrapolating the results to zero stretch. Consequently, lean and rich flammability limits were determined for a large variety of mixtures. By further hypothesizing that the limit phenomena are primarily controlled by the kinetic processes of chain branching versus termination, a predictive theory was advanced for the a priori determination of flammability limits. Conclusions based on the results of the study are presented.

• Research Organization: California Univ., Davis, CA (United States)
• OSTI ID: 5563664
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400800* -- Combustion
Pyrolysis
& High-Temperature Chemistry
CHEMICAL REACTION KINETICS
COMBUSTION KINETICS
FLAME PROPAGATION
FLUID FLOW
KINETICS
LAMINAR FLOW
PRESSURE EFFECTS
REACTION KINETICS
TEMPERATURE DISTRIBUTION