Influence of the Damkohler number on the average thickness of conical turbulent premixed methane/air flames

Journal Article · Fri Jul 01 04:00:00 EDT 1988 · Combust. Flame; (United States)

DOI:https://doi.org/10.1016/0010-2180(88)90054-5· OSTI ID:6833691

Boukhalfa, A; Gokalp, I

The density field of six open conical turbulent premixed methane/air flames is investigated by Rayleigh scattering. They are stabilized by an annular pilot flame at the rim of a 16 mm diameter brass tube burner. The cold flow turbulence structure is that of fully developed pipe flow. Six combinations of three exit Reynolds numbers and four equivalence ratios give large eddy Damkohler numbers ranging between 9 and 30, and small eddy Damkohler numbers ranging between 0.80 and 2.90. Pairs of these flames fall within the wrinkled laminar, corrugated, and thickened flame regimes. Flame heights and average flame thicknesses are deduced from centerline and transverse evolutions of the mean density. The variations of the average flame thickness (normalized either by the cold flow turbulence longitudinal integral length scale or the corresponding visible laminar thickness) with respect to large and small eddy Damkohler numbers and the global density ratio are discussed and compared to available theoretical predictions.

• Research Organization: Centre de Recherches sur la Chimie de la Combustion et des Hautes Temperatures, Orleans (FR)
• OSTI ID: 6833691
• Journal Information: Combust. Flame; (United States), Journal Name: Combust. Flame; (United States) Vol. 73:1; ISSN CBFMA
• Country of Publication: United States
• Language: English

Related Subjects

090110* -- Hydrocarbon Fuels-- Properties-- (1979-1989)
10 SYNTHETIC FUELS
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400800 -- Combustion
Pyrolysis
& High-Temperature Chemistry
AIR
ALKANES
CALCULATION METHODS
CHEMICAL REACTION KINETICS
COMBUSTION KINETICS
DENSITY
FLAME PROPAGATION
FLUID FLOW
FLUIDS
FUEL-AIR RATIO
GASES
HYDROCARBONS
KINETICS
LAMINAR FLOW
METHANE
ORGANIC COMPOUNDS
PHYSICAL PROPERTIES
REACTION KINETICS
REYNOLDS NUMBER
SCATTERING
TURBULENCE