Turbulent nonpremixed flames of methane near extinction

Journal Article · Thu Sep 01 00:00:00 EDT 1988 · Combust. Flame; (United States)

DOI:https://doi.org/10.1016/0010-2180(88)90023-5· OSTI ID:6476135

Masri, A R; Bilger, R W ^[1]; Dibble, R W ^[2]

---

1. Dept. of Mechanical Engineering, The Univ. of Sydney (AU)
2. Combustion Research Facility, Sandia Nationalal Labs., Livermore, CA (US)

Space- and time-resolved measurements of major species concentrations and temperature have been made using the Raman-Rayleigh scattering technique in the blue (visibly soot free) regions of turbulent nonpremixed flames of methane close to extinction. The data are presented in this paper in the form of single variate probability density functions (pdfs) for the mixture fraction, temperature, and the mass fractions of CH/sub 4/, O/sub 2/, H/sub 2/O, H/sub 2/, CO/sub 2/ and CO. Representative instantaneous scatter plots and joint pdfs are also shown. When the mixing rates are low, the data show mostly fully burnt mixtures indicating that the chemistry is relatively fast. As the flame approaches extinction, most local mixtures become either partially burn or simply mixed. The joint pdfs shown bimodality for mixture fractions less than --.1 and centered distributions for richer mixtures. When close to extinction, fully burnt pockets of fluid are still encountered and these may be responsible for keeping the flame alight. Questions relating to the local, instantaneous flame structure near extinction are discussed in light of existing theoretical models.

• OSTI ID: 6476135
• Journal Information: Combust. Flame; (United States), Journal Name: Combust. Flame; (United States) Vol. 73:3; 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
ALKANES
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CLUSTER EMISSION MODEL
COHERENT SCATTERING
COMBUSTION KINETICS
DENSITY
DISPERSIONS
ELEMENTS
FLAMES
HYDROCARBONS
HYDROGEN
HYDROGEN COMPOUNDS
KINETICS
MATHEMATICAL MODELS
METHANE
MIXTURES
MULTIPERIPHERAL MODEL
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PARTICLE MODELS
PERIPHERAL MODELS
PHYSICAL PROPERTIES
PROBABILISTIC ESTIMATION
RAMAN SPECTRA
RAYLEIGH SCATTERING
REACTION KINETICS
SCATTERING
SPACE-TIME MODEL
SPECTRA
WATER