Stability of CH4-N2/air jet diffusion flame for various burner rim thicknesses

Yasuhiro Otakeyama, Takeshi Yokomori, Masahiko Mizomoto

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

The influence of burner rim thickness on the stabilization mechanism of methane diluted with nitrogen and air jet diffusion flame was investigated experimentally. The diffusion flame was stabilized on a two-dimensional Wolfhard-Parker burner with a variable partition wall (burner rim) thickness between the fuel and air jets. The diffusion flame on a thin burner rim showed a blowout at the stability limit, which occurred after the lifted flame behavior. For a thick burner rim, the flame base remained well anchored in the wake region, and a blowoff occurred suddenly and not via the lifted flame with an increase in the jet velocity. For moderate rim thickness, a transition from a wake-anchored flame to a lifted flame appeared (liftoff), and blowout then occurred as the jet velocity increased. The blowout limits of lifted flames were not influenced by rim thickness; however, the blowoff limits were extended with an increase in the rim thickness. Particle image velocimetry (PIV) measurements showed that unburned flow entrainment into the base of the lifted flame was of the same order of magnitude as the propagation speed of the premixed flame. Therefore, the stabilization of the lifted diffusion flame for a thin rim might be determined by the premixed propagation of the flame base. On the other hand, a flame base anchored on the thick burner rim experienced a velocity distribution similar to a counterflow. Furthermore, the stretch rates at the liftoff and blowoff limits agreed well with the extinction limits of ordinary counterflow diffusion flames. Thus, their mechanisms could be explained by flame stretched extinction.

Original languageEnglish
Pages (from-to)1091-1097
Number of pages7
JournalProceedings of the Combustion Institute
Volume32 I
DOIs
Publication statusPublished - 2009

Fingerprint

air jets
diffusion flames
burners
rims
Fuel burners
flames
Air
flameout
Stabilization
counterflow
wakes
Methane
Velocity distribution
extinction
Velocity measurement
stabilization
jet engine fuels
Nitrogen
propagation
premixed flames

Keywords

  • Blowoff
  • Diffusion flame
  • Liftoff
  • Stabilization mechanism
  • Stretched extinction

ASJC Scopus subject areas

  • Mechanical Engineering
  • Chemical Engineering(all)
  • Physical and Theoretical Chemistry

Cite this

Stability of CH4-N2/air jet diffusion flame for various burner rim thicknesses. / Otakeyama, Yasuhiro; Yokomori, Takeshi; Mizomoto, Masahiko.

In: Proceedings of the Combustion Institute, Vol. 32 I, 2009, p. 1091-1097.

Research output: Contribution to journalArticle

@article{06491b3a7e4242f4acd8eb8c30aefb4b,
title = "Stability of CH4-N2/air jet diffusion flame for various burner rim thicknesses",
abstract = "The influence of burner rim thickness on the stabilization mechanism of methane diluted with nitrogen and air jet diffusion flame was investigated experimentally. The diffusion flame was stabilized on a two-dimensional Wolfhard-Parker burner with a variable partition wall (burner rim) thickness between the fuel and air jets. The diffusion flame on a thin burner rim showed a blowout at the stability limit, which occurred after the lifted flame behavior. For a thick burner rim, the flame base remained well anchored in the wake region, and a blowoff occurred suddenly and not via the lifted flame with an increase in the jet velocity. For moderate rim thickness, a transition from a wake-anchored flame to a lifted flame appeared (liftoff), and blowout then occurred as the jet velocity increased. The blowout limits of lifted flames were not influenced by rim thickness; however, the blowoff limits were extended with an increase in the rim thickness. Particle image velocimetry (PIV) measurements showed that unburned flow entrainment into the base of the lifted flame was of the same order of magnitude as the propagation speed of the premixed flame. Therefore, the stabilization of the lifted diffusion flame for a thin rim might be determined by the premixed propagation of the flame base. On the other hand, a flame base anchored on the thick burner rim experienced a velocity distribution similar to a counterflow. Furthermore, the stretch rates at the liftoff and blowoff limits agreed well with the extinction limits of ordinary counterflow diffusion flames. Thus, their mechanisms could be explained by flame stretched extinction.",
keywords = "Blowoff, Diffusion flame, Liftoff, Stabilization mechanism, Stretched extinction",
author = "Yasuhiro Otakeyama and Takeshi Yokomori and Masahiko Mizomoto",
year = "2009",
doi = "10.1016/j.proci.2008.05.002",
language = "English",
volume = "32 I",
pages = "1091--1097",
journal = "Proceedings of the Combustion Institute",
issn = "1540-7489",
publisher = "Elsevier Limited",

}

TY - JOUR

T1 - Stability of CH4-N2/air jet diffusion flame for various burner rim thicknesses

AU - Otakeyama, Yasuhiro

AU - Yokomori, Takeshi

AU - Mizomoto, Masahiko

PY - 2009

Y1 - 2009

N2 - The influence of burner rim thickness on the stabilization mechanism of methane diluted with nitrogen and air jet diffusion flame was investigated experimentally. The diffusion flame was stabilized on a two-dimensional Wolfhard-Parker burner with a variable partition wall (burner rim) thickness between the fuel and air jets. The diffusion flame on a thin burner rim showed a blowout at the stability limit, which occurred after the lifted flame behavior. For a thick burner rim, the flame base remained well anchored in the wake region, and a blowoff occurred suddenly and not via the lifted flame with an increase in the jet velocity. For moderate rim thickness, a transition from a wake-anchored flame to a lifted flame appeared (liftoff), and blowout then occurred as the jet velocity increased. The blowout limits of lifted flames were not influenced by rim thickness; however, the blowoff limits were extended with an increase in the rim thickness. Particle image velocimetry (PIV) measurements showed that unburned flow entrainment into the base of the lifted flame was of the same order of magnitude as the propagation speed of the premixed flame. Therefore, the stabilization of the lifted diffusion flame for a thin rim might be determined by the premixed propagation of the flame base. On the other hand, a flame base anchored on the thick burner rim experienced a velocity distribution similar to a counterflow. Furthermore, the stretch rates at the liftoff and blowoff limits agreed well with the extinction limits of ordinary counterflow diffusion flames. Thus, their mechanisms could be explained by flame stretched extinction.

AB - The influence of burner rim thickness on the stabilization mechanism of methane diluted with nitrogen and air jet diffusion flame was investigated experimentally. The diffusion flame was stabilized on a two-dimensional Wolfhard-Parker burner with a variable partition wall (burner rim) thickness between the fuel and air jets. The diffusion flame on a thin burner rim showed a blowout at the stability limit, which occurred after the lifted flame behavior. For a thick burner rim, the flame base remained well anchored in the wake region, and a blowoff occurred suddenly and not via the lifted flame with an increase in the jet velocity. For moderate rim thickness, a transition from a wake-anchored flame to a lifted flame appeared (liftoff), and blowout then occurred as the jet velocity increased. The blowout limits of lifted flames were not influenced by rim thickness; however, the blowoff limits were extended with an increase in the rim thickness. Particle image velocimetry (PIV) measurements showed that unburned flow entrainment into the base of the lifted flame was of the same order of magnitude as the propagation speed of the premixed flame. Therefore, the stabilization of the lifted diffusion flame for a thin rim might be determined by the premixed propagation of the flame base. On the other hand, a flame base anchored on the thick burner rim experienced a velocity distribution similar to a counterflow. Furthermore, the stretch rates at the liftoff and blowoff limits agreed well with the extinction limits of ordinary counterflow diffusion flames. Thus, their mechanisms could be explained by flame stretched extinction.

KW - Blowoff

KW - Diffusion flame

KW - Liftoff

KW - Stabilization mechanism

KW - Stretched extinction

UR - http://www.scopus.com/inward/record.url?scp=67649246825&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=67649246825&partnerID=8YFLogxK

U2 - 10.1016/j.proci.2008.05.002

DO - 10.1016/j.proci.2008.05.002

M3 - Article

VL - 32 I

SP - 1091

EP - 1097

JO - Proceedings of the Combustion Institute

JF - Proceedings of the Combustion Institute

SN - 1540-7489

ER -