Effects of oxidizer preheating and dilution on the extinction and structure of CH4-O2-Ar diffusion flames

Kunihito Hamatsu, Yuji Yahagi, Masao Takeuchi, Shingo Nakahara

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1 Citation (Scopus)


The effects of oxidizer preheating and dilution levels of fuel and exygen on the extinction and structure of counterflow CH4-O2-Ar diffusion flame were investigated experimentally and numerically. The oxidizer temperature of both experiments and calculations were varied up to 1100 K. The oxidizer preheating significantly contributes to expansion of the extinction limits. The oxidizer preheating and the dilution levels are characterized by the magnitude of stoichiometric mixture fraction (Fst). The extinction limit curves can be roughly divided into two regions based on the magnitude of Fst. In the region about Fst<0.5 which the flame location is in the oxidizer flow side, the oxidizer concentration exerts dominant effect on the extinction, and the effects of preheating is clearly observed. In this region, the combustion reaction appears with oxidizer preheating from the upper of oxidizer side. On the other hand, the region about Fst>0.5, which the flame is located to the fuel flow, the expansion of reaction zone with preheating is almost small. Only small effects of the oxidizer preheating to the extinction limits are observed in this region. As the results, the flame location is quite important factor to understand the effects of dilution levels and oxidizer preheating on the extinction phenomena.

Original languageEnglish
Pages (from-to)1052-1059
Number of pages8
JournalNihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B
Issue number4
Publication statusPublished - 2006
Externally publishedYes


  • Combustion Phenomena
  • Counterflow
  • Diffusion Combustion
  • Energy Saving
  • Extinction
  • High Temperature Air Combustion

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanical Engineering


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