NIST Time|NIST Home|About NIST|Contact NIST

HomeAll Years:AuthorKeywordTitle2005-2010:AuthorKeywordTitle

Simulation of Cup-Burner Flames in Microgravity.


pdf icon Simulation of Cup-Burner Flames in Microgravity. (1146 K)
Katta, V. R.; Takahashi, F.; Linteris, G. T.

Combustion Institute/Central States Section. Third (3rd) Joint Meeting of the U.S. Sections. Session A4: Combustion I. Hosted by The Central States Section of the Combustion Institute and the University of Illinois at Chicago. March 16-19, 2003, Chicago, IL, A18/1-6 pp, 2003.

Keywords:

microgravity; simulations; carbon dioxide; cup Burner; fire suppression; flame extinction; flame stabilization

Abstract:

The extinction process of cup-burner flames under normal-gravity conditions were previously studied. As the low-speed diffusion flames behave differently in microgravity compared to those on earth, it is important to understand the structure of cup-burner flame and its extinction characteristics under 0g conditions. A numerical study was performed in the present paper using a time-dependent, axisymmetric model and by incorporating detailed chemical kinetics of CH4 and O2. Calculations were performed for the cup-burner flame under different gravitational forces. It was observed that the cup-burner flame ceases to flicker under gravitational forces less than 0.5g. As the buoyancy force was reduced, the flame diameter increased, the tip of the flame opened, and the flame at the base became vertical. Through numerical experiments it was found that radiative heat loss was predominantly responsible for the extinction of flame in the tip region under 0g conditions. In contrast, 1g flames were not affected much by the radiative heat loss.