한국연소학회:학술대회논문집

The Korean Society of Combustion (한국연소학회)
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Laminar Lifted Methane Jet Flames in Co-flow Air

  • Sapkal, Narayan P. (Pukyong National University, Department of Mechanical Engineering, Combustion and Propulsion Lab.) ;
  • Lee, Won June (Pukyong National University, Department of Mechanical Engineering, Combustion and Propulsion Lab.) ;
  • Park, Jeong (Pukyong National University, Department of Mechanical Engineering, Combustion and Propulsion Lab.) ;
  • Lee, Byeong Jun (Pukyong National University, Department of Mechanical Engineering, Combustion and Propulsion Lab.) ;
  • Kwon, Oh Boong (Pukyong National University, Department of Mechanical Engineering, Combustion and Propulsion Lab.)
  • Published : 2015.12.10
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Abstract

The Laminar lifted methane jet flames diluted with helium and nitrogen in co-flow air have been investigated experimentally. The chemiluminescence intensities of $OH^{\ast}$ and $CH_2O^{\ast}$ radicals and the radius of curvature for tri-brachial flame were measured using an intensified charge coupled device (ICCD) camera, monochromator and digital video camera. The product of $OH^{\ast}$ and $CH_2O^{\ast}$ is used as a excellent proxy of heat release rate. These methane jet flames could be lifted in buoyancy and jet dominated regimes despite the Schmidt number less than unity. Lifted flames were stabilized due to buoyancy induced convection in buoyancy-dominated regime. It was confirmed that increased $OH^{\ast}$ and $CH_2O^{\ast}$ concentration caused an increase of edge flame speed via enhanced chemical reaction in buoyancy dominated regime. In jet momentum dominated regime lifted flames were observed even for nozzle exit velocities much higher than stoichiometric laminar flame speed. An increase in radius of curvature in addition to the increased $OH^{\ast}$ and $CH_2O^{\ast}$ concentration stabilizes such lifted flames.

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