Experimental Study on Behavior near Extinction in Buoyancy-minimized Counterflow Diffusion Flame

부력 효과의 최소화를 통한 소화 근처 대향류 확산화염 거동에 관한 실험적 연구

  • 정용호 (부경대학교 에너지시스템공학과) ;
  • 박정 (부경대학교 기계공학과) ;
  • 권오붕 (부경대학교 기계공학과) ;
  • 윤진한 (한국 기계연구원 그린환경에너지기계본부) ;
  • 길상인 (한국 기계연구원 그린환경에너지기계본부) ;
  • 김태형 (한국전력연구원 수화력발전팀) ;
  • 김영주 (한국전력연구원 수화력발전팀)
  • Published : 2012.11.30

Abstract

Experimental study was conducted to elucidate flame extinction phenomena in counterflow flame. Using a curtain helium flow significantly reduced buoyancy such that the flame can be positioned at the center between the upper and lower nozzles even at the velocity ratio of 1.0. The curves of critical diluent mole fraction versus global strain rate have C-shapes. The flame oscillation was observed prior to low strain rate flame extinction at both flame conditions with and without minimizing buoyancy force. The results show that, at low strain rate flame, the self-excitation frequency with the order of 1.0 Hz in the case of utilizing pure helium gradually decreases in increase of $N_2$ mole fraction in the curtain flow, meaning that buoyancy suppresses the self-excitation of the outer edge flame.

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