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U.S. Department of Energy
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Enhanced soot formation in flickering CH{sub 4}/air diffusion flames

Conference ·
OSTI ID:254692
; ;  [1]
  1. National Institute of Standards and Technology, Gaithersburg, MD (United States)

Optical methods are used to examine soot production in a co-flowing, axisymmetric CH{sub 4}/air diffusion flame in which the fuel flow rate is acoustically forced to create a time-varying flowfield. For a particular forcing condition in which tip clipping occurs (0.75 V loudspeaker excitation), elastic scattering of vertically polarized light from the soot particles increases by nearly an order of magnitude with respect to that observed for a steady flame with the same mean fuel flow rate. Peak soot volume fractions, as measured by time-resolved laser extinction/tomography at 632.8 and 454.5 run and calibrated laser-induced incandescence (LII), show a factor of 4-5 enhancement in this flickering flame. A Mie analysis suggests that most of the enhanced soot production results from the formation of larger particles in the time-varying flowfield.

OSTI ID:
254692
Report Number(s):
CONF-940813--
Country of Publication:
United States
Language:
English