An Experimental Study on Liftoff and Reattachment Characteristics in Concentric Burner

프로판 동축류 확산 화염에서 화염 부상과 재부착에 관한 실험적 연구

  • 박성호 (서울대학교 대학원 기계항공공학부) ;
  • 원상희 (서울대학교 대학원 기계항공공학부) ;
  • 차민석 (한국기계연구원) ;
  • 정석호 (서울대학교 기계항공공학부)
  • Published : 2001.11.16

Abstract

Propane coflow diffusion flames have been experimentally studied to investigate the liftoff and reattachment characteristics. Flame properties such as velocity and density distribution were measured by LDV and shadowgraphy, respectively. It is shown that as the velocity of coflowing air increases, liftoff velocity decreases nonlinearly in turbulent jets and linearly in laminar jets, while reattachment velocity decreases nonlinearly. Meanwhile, as inner nozzle tip thickness increases, liftoff velocity increases with the reattachment velocity nearly unchanged. Liftoff phenomena in these flames can be categorized into three classes as a function of coflow velocity, such as laminar liftoff, turbulent liftoff, and transient liftoff.

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