Stability of diffusion flame formed in a laminar flat plate boundary layer (effect of fuel dilution)

Masao Takeuchi, Toshihisa Ueda, Tomoya Amari, Masahiko Mizumoto

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

A stability limit of the diffusion flame with fuel injection from a porous wall in a laminar flat plate boundary layer is measured as functions of fuel (CH4) concentration of CH4/N2 injectant mixture (x) and its injection velocity (v). The free stream velocity (U8) is set as 0.6 m/s. The thermal condition at the wall is controlled by setting temperature at the upstream end of the porous wall as a reference temperature. When v>20 mm/s, the flame becomes unstable with the separation of leading flame edge with decreasing x. The value of x at the stability limit is constant without regard to v as long as the wall temperatrure is kept constant. As the wall temperature is decreased the value of x increases. The separation is supposed to take place as a result of the limit of the reaction rate. When υ<20 mm/s, the flame becomes unstable with the oscillation. The value of x at the stability limit increases drastically with decreasing v. The oscillation takes place mainly due to the repeat of the extinction due to heat loss to the wall and the flame propagation in the combustible layer.

Original languageEnglish
Pages (from-to)3485-3490
Number of pages6
JournalNihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B
Volume64
Issue number626
DOIs
Publication statusPublished - 1998 Oct

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Keywords

  • Diffusion combustion
  • Flame
  • Flame stability
  • Fuel dilution
  • Wall boundary layer

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanical Engineering

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