An Experimental Study on the Flame Structure of Partially Premixed Flame using OH PLIF

OH PLIF를 이용한 부분 예혼합 화염의 화염구조에 관한 실험적 연구

  • 이승영 (부산대학교 대학원 기계공학과) ;
  • 이종호 (부산대학교 대학원 기계공학과) ;
  • 전충환 (부산대학교 기계공학부, 기계기술연구소) ;
  • 장영준 (부산대학교 기계공학부, 기계기술연구소)
  • Published : 2001.06.27

Abstract

OH radical concentration have been measured in a methane-air partially premixed flames using PLIF. Excitation lines were selected $Q_{1}(6)$ branch, (1,0) band. The system is consisted of Nd:YAG laser, dye laser and frequency doubler to make pump beam for OH radical. On the direct photographs, flame height increases as fuel flow rate and equivalence ratio increase. And on the PLIF images, OH radical is distributed from premixed flame front to nonpremixed flame front through the flame structure with all equivalence ratio. OH overall concentrations increase with equivalence ratio. At the stoichiometric equivalence ratio, the peak of OH radical concentration exists strongly near the inner cone. As equivalence ratio is changed to richer, OH radical distribution goes thinly and the peak is increased as longitudinal direction. As the flow goes to the downstream, OH radical concentration decreases and broadens, because OH radical reacts with another species after OH formation at the initial oxidization. This phenomenon resembles radial distribution. At the l00cc fuel flowrate, the radial peak of OH radical exists from x/R=l.0 to 1.5.

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