Spark ignition and the early stages of turbulent flame propagation

Journal Article · Wed Jul 01 04:00:00 EDT 1987 · Combust. Flame; (United States)

DOI:https://doi.org/10.1016/0010-2180(87)90022-8· OSTI ID:5881987

Bradley, D; Lung, F K.K.

A hydrodynamic mathematical model is presented for the ignition of gaseous mixtures. Solution schemes are discussed and computed results presented for the initial shock wave propagation and the slower spreading of the thermal wave from the narrow spark discharge channel. Different spark power-time profiles are analyzed and it is clear that a central problem is the slow spread of energy from the discharge channel to ignite a critical volume. Ignition delay times are presented, based upon thermal ignition criteria. Minimum ignition energy is increased for turbulent mixtures because of the effects of flame straining. Ignition experiments are reported for a fan-stirred bomb. Spark power profiles and turbulent velocities were controlled and CH emission intensities measured. Ignition and flame development were traced from high speed schlieren photographs. Three regimes are delineated: localized ignition; spark assisted flame propagation; and normal propagation.

• Research Organization: Dept. of Mechanical Engineering, Univ. of Leeds, Leeds LS2 9JT
• OSTI ID: 5881987
• Journal Information: Combust. Flame; (United States), Journal Name: Combust. Flame; (United States) Vol. 69:1; ISSN CBFMA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400800 -- Combustion
Pyrolysis
& High-Temperature Chemistry
45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
450100* -- Military Technology
Weaponry
& National Defense-- Chemical Explosions & Explosives
BLOWERS
CHEMICAL REACTION KINETICS
COMBUSTION KINETICS
ELECTRIC DISCHARGES
ELECTRIC SPARKS
EMISSION
EXPLOSIVES
FLAME PROPAGATION
FLAMES
FLUID FLOW
FLUID MECHANICS
HYDRODYNAMICS
IGNITION
IGNITION QUALITY
IMAGES
KINETICS
MATHEMATICAL MODELS
MEASURING METHODS
MECHANICS
PHOTOGRAPHY
REACTION KINETICS
SHOCK WAVES
TURBULENT FLOW
WAVE PROPAGATION