0
Research Papers: Gas Turbines: Combustion, Fuels, and Emissions

Characteristics of Flame Modes for a Conical Bluff Body Burner With a Central Fuel Jet

[+] Author and Article Information
Min Zhu

e-mail: zhumin@tsinghua.edu.cn
Key Laboratory for Thermal Science
and Power Engineering,
Department of Thermal Engineering,
Tsinghua University,
Beijing 100084, China

Contributed by the Combustion and Fuels Committee of ASME for publication in the Journal of Engineering for Gas Turbines and Power. Manuscript received June 26, 2013; final manuscript received July 1, 2013; published online August 19, 2013. Editor: David Wisler.

J. Eng. Gas Turbines Power 135(9), 091507 (Aug 19, 2013) (9 pages) Paper No: GTP-13-1186; doi: 10.1115/1.4024951 History: Received June 26, 2013; Revised July 01, 2013

Bluff body stabilized nonpremixed flames are usually used as pilot flames in lean-premixed combustors. Experiments are conducted to investigate the characteristics of the flame. Typical flame modes are investigated in both stable and unstable conditions. The flow structures, the reaction zone, and the dynamics of unstable flames are measured with particle image velocimetry (PIV), intensified charge-coupled device (ICCD) and a high-speed camera, respectively, based on which the inherent mechanisms that influence the configuration and stabilization of the flame are analyzed. Stable flames are apparently influenced by the mixing characteristics in the recirculation zone. Flame detachment, a typical phenomenon of stable flames in a turbulent air flow, can be explained by the distribution of fuel concentration in the recirculation zone. The Reynolds number of air has different effects on different parts of the flame, which results in three unstable flame modes at different Reynolds numbers of air. These results could be helpful for the design of stable burners in practice.

Copyright © 2013 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

Schematic of a typical flow field of a bluff body burner with a central fuel jet [2,3]

Grahic Jump Location
Fig. 2

Schematic of the experimental setup

Grahic Jump Location
Fig. 3

Flame diagram. —: unstable limit; – –:blowout limit; -·-: boundary of split flames. The numbered symbols indicate typical conditions discussed in the following. ★: stable flames at laminar air flow; ◀: stable flames at transitional-state air flow; ●: stable flames at turbulent air flow; △: split-flashing flame; ○: split flame; ♦: lift-off flame.

Grahic Jump Location
Fig. 4

Schlieren images for flames at different air Reynolds numbers. Ref = 640

Grahic Jump Location
Fig. 5

Flame images in laminar air flow. Rea = 1710

Grahic Jump Location
Fig. 6

OH* distributions in laminar air flow. Rea = 1710

Grahic Jump Location
Fig. 7

Mie-scattering images in laminar air flow. Rea = 1710. The dashed line indicates the positions of the flame.

Grahic Jump Location
Fig. 8

Mie-scattering images at turbulent air flow. The regions in the dashed rectangle denote the pure fuel jet without particles. Rea = 13,300.

Grahic Jump Location
Fig. 9

Transient streamlines at turbulent air flow. The black regions denote the pure fuel jet without particles. Rea = 13,300.

Grahic Jump Location
Fig. 10

Averaged streamlines and vorticity distributions at turbulent air flow. The white regions denote the pure fuel jet without particles. Rea = 13,300.

Grahic Jump Location
Fig. 11

Flame images at turbulent air flow. Rea = 13,300.

Grahic Jump Location
Fig. 12

OH* distributions at turbulent air flow. Rea = 13,300.

Grahic Jump Location
Fig. 13

Dimensionless average flame detachment height versus velocity ration at different Rea values

Grahic Jump Location
Fig. 14

Strain rate for a flame near the unstable phenomenon limit. The white region denotes the pure fuel jet without particles. Conditions No. 5: Rea = 2850, Ref = 3200.

Grahic Jump Location
Fig. 15

Images for unstable flame modes (a) No. 11: Rea = 380, Ref = 6350; (b) No. 12: Rea = 1220, Ref = 6350; (c) No. 13: Rea = 13,300, Ref = 8900

Grahic Jump Location
Fig. 16

Mie images for liftoff flame and split flame condition (a) No. 11: Rea = 380, Ref = 6350; (b) No. 12: Rea = 1220, Ref = 9500

Grahic Jump Location
Fig. 17

Evolutions of the flame segments for split-flashing flames. The interval between two adjacent images is 0.03 s. Conditions No. 14: Rea = 13,300, Ref = 19,100.

Grahic Jump Location
Fig. 18

Schematic of the paths of flames segment for split-flashing flames. The interval between two adjacent images is 0.03 s. Conditions No. 14: Rea = 13,300, Ref = 19,100.

Grahic Jump Location
Fig. 19

Luminance intensity for split-flashing flames Rea = 13,300

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In