https://www.nist.gov/system/files/documents/el/fire_research/R0501586.pdf
PHYSICAL AND CHEMICAL ASPECTS OF CUP-BURNER FLAME
EXTINGUISHMENT
Fumiaki Takahashi
National Center for Space Exploration Research on Fluids and Combustion
NASA Glenn Research Center, Cleveland, OH 44135 USA
Tel: 216-433-3778; Fax: 216-433-8050; Fumiaki.Takahashi@grc.nasa.gov
Gregory T. Linteris
Fire Research Division, National Institute of Standards and Technology
Gaithersburg, MD 20899 USA
Tel: 301-975-2283; Fax: 301-975-4052; linteris@nist.gov
Viswanath R. Katta
Innovative Scientific Solutions, Inc., Dayton, OH, 45440 USA
Tel: 937-255-8781; Fax: 937-656-4110; vrkatta@erinet.com
*
ABSTRACT
Extinguishing limits of laminar methane-air co-flow diffusion flames in a cup-burner apparatus
in normal earth gravity have been determined experimentally and computationally. A gaseous
fire-extinguishing agent (Ar, He, N2, CO2, CF3H, CF3Br, or Br2) was added gradually into the
coflowing oxidizer until the flame extinguished. The extinguishment of cup-burner flames,
which resemble real fires, occurred via a blowoff process (in which the flame base oscillated
before drifted downstream eventually) rather than the global extinction typical of counterflow
diffusion flames. Unsteady numerical simulations with detailed chemistry revealed that the peak
reactivity spot (i.e., reaction kernel), formed at the flame attach...