A comparison of the velocity and scalar spectra in premixed turbulent flames

Journal Article · Wed Nov 01 04:00:00 EST 1989 · Combustion and Flame; (USA)

DOI:https://doi.org/10.1016/0010-2180(89)90126-0· OSTI ID:5368676

Cheng, R K; Shepherd, I G ^[1]; Gokalp, I ^[2]

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1. Lawrence Berkeley Lab., CA (USA). Applied Science Div.
2. CRCCHT-CNRS, 45071 Orleans Cedex 2 (FR)

Frequency spectra for scalar and two velocity components in premixed methane-air turbulent {nu}-flames and stagnation flow-stabilized flames have been measured using laser light Mie scattering and laser Doppler anemometry techniques. To assist in interpreting the influence of flame crossing phenomenon on the scalar spectra, theoretical predictions of the spectra developed by Bray-Libby-Moss and by Bray-Libby were evaluated. The spectral slopes and most energetic frequencies of the scalar spectra were compared with those of the velocity components normal and tangential to the turbulent flame brush. In both configurations, the spectra of the normal velocity components are similar to the corresponding scalar spectra, demonstrating the coupling between velocity and scalar spectra. However, the most energetic frequencies, which are related to the flame crossing frequencies, are about an order of magnitude higher in the {nu}-flame than in the stagnation flames. Because this difference does not seem to be proportional to the difference in the mean velocities, the results imply that the spatial scale distribution in the two flame zones are not the same.

• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5368676
• Journal Information: Combustion and Flame; (USA), Journal Name: Combustion and Flame; (USA) Vol. 78:2; ISSN CBFMA; ISSN 0010-2180
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102 -- Chemical & Spectral Procedures
400800* -- Combustion
Pyrolysis
& High-Temperature Chemistry
42 ENGINEERING
420400 -- Engineering-- Heat Transfer & Fluid Flow
AIR
ALKANES
DISPERSIONS
FLAMES
FLUID FLOW
FLUIDS
GASES
HYDROCARBONS
METHANE
MIXTURES
ORGANIC COMPOUNDS
SPECTRA
TURBULENT FLOW
VELOCITY