Liftoff mechanisms in hydrogen turbulent non-premixed jet flames

수소 난류확산화염에서의 부상 메커니즘에 대한 연구

  • 오정석 (서울대학교 공과대학 기계항공공학부) ;
  • 김문기 (서울대학교 공과대학 기계항공공학부) ;
  • 최영일 (서울대학교 공과대학 기계항공공학부) ;
  • 윤영빈 (서울대학교 공과대학 기계항공공학부)
  • Published : 2007.05.04

Abstract

To reveal the newly found liftoff height behavior of hydrogen jet, we have experimentally studied the stabilization mechanism of turbulent, lifted jet flames in a non-premixed condition. The objectives of the present research are to report the phenomenon of a liftoff height decreasing as increasing fuel velocity, to analyse the flame structure and behavior of the lifted jet, and to explain the mechanisms of flame stability in hydrogen turbulent non-premixed jet flames. The velocity of hydrogen was varied from 100 to 300m/s and a coaxial air velocity was fixed at 16m/s with a coflow air less than 0.1m/s. For the simultaneous measurement of velocity field and reaction zone. PIV and OH PLIF technique was used with two Nd:Yag lasers and CCD cameras. As results, it has been found that the stabilization of lifted hydrogen diffusion flames is related with a turbulent intensity, which means that combustion occurs where the local flow velocity is valanced with the turbulent flame propagation velocity.

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