報文

Two-Dimensional Observation of Fluctuation
in Methane-Air / LPG-Air Premixed Flames
by Planar Laser-Induced Fluorescence (PLIF)

Atsushi KATOH, Hiroyuki OYAMA, Kuniyuki KITAGAWA,
and Ashwani K. GUPTA

　OH-PLIF images were observed sequentially at a rate of 30 frames/sec on CH4-air and liquefied petroleum gas (LPG)-air premixed flames, followed by statistical analysis including Fast Fourier Transformation (FFT) to examine flame fluctuations at inner and outer regions of the premixed flames. Characteristics in the FFT power spectra were different between the inner and outer cases due to a difference in mixing condition of the fuel gas and air between the inner and outer flame regions. Correlation profiles betweenaverage value and standard deviation of the consecutively measured OH-PLIF intensity showed that combustion reaction activity was not always a prevailing driving force for the fluctuation. This characteristic was independent of the difference in mixing condition of the fuel gas and air between the inner and outer flame regions.

Keywords: Flame fluctuation, premixed flames, OH-PLIF distribution, statistical analysis