Experiments on the scalar structure of turbulent CO/H{sub 2}/N{sub 2} jet flames
Scalar and velocity measurements are reported for two turbulent jet flames of CO/H{sub 2}/N{sub 2} (40/30/30 volume percent) having the same jet Reynolds number of 16,700 but different nozzle diameters (4.58 mm and 7.72 mm). Simultaneous measurements of temperature, the major species, OH, and NO are obtained using the combination of Rayleigh scattering, Raman scattering, and laser-induced fluorescence. This paper focuses on the scalar results but includes some limited velocity data. Axial profiles of mixture fraction, major species mole fractions, and velocity in these two flames are in close agreement when streamwise distance is scaled by nozzle diameter. Turbulent flame measurements are compared with steady strained laminar flame calculations. Laminar calculations show remarkable close agreement with measured conditional means of the major species when all diffusivities are set equal to the thermal diffusivity. In contrast, laminar flame calculations that include the normal Chemkin treatment of molecular transport are clearly inconsistent with the measurements. These results suggest that turbulent stirring has a greater influence than molecular diffusion in determining major species concentrations at the flow conditions and locations considered in the present experiments, which begin at an axial distance of 20 nozzle diameters. Aspects of the measurements, including Favre-averaged profiles, conditional statistics, mixture fraction pdf's, and departures from partial equilibrium, are presented and discussed in terms or their relevance to the testing of turbulent combustion submodels. The complete data are available on the World Wide Web for use in model validation studies.
- Research Organization:
- Sandia National Labs., Livermore, CA (US)
- OSTI ID:
- 20019027
- Journal Information:
- Combustion and Flame, Journal Name: Combustion and Flame Journal Issue: 4 Vol. 120; ISSN CBFMAO; ISSN 0010-2180
- Country of Publication:
- United States
- Language:
- English
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