Hostname: page-component-cd9895bd7-q99xh Total loading time: 0 Render date: 2024-12-25T17:09:16.208Z Has data issue: false hasContentIssue false
  • English
  • Français

Behaviors of Flame and Flow of Swirling Wake During Fuel Jet Oscillation Due to Acoustic Excitations

Published online by Cambridge University Press:  05 May 2011

M. E. Loretero  and
R. F. Huang
M. E. Loretero*
Affiliation:
Department of Mechanical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan 10607, R.O.C.
R. F. Huang*
Affiliation:
Department of Mechanical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan 10607, R.O.C.
*
* Graduate student
** Professor, corresponding author
Get access

Abstract

The flame and flow behaviors along with the fuel jet oscillations of non-premixed and axisymmetric swirling wake during acoustic excitations are studied experimentally. Visual observations on the reaction zones are carried out to identify the flame behaviors. Close-up images at the flame base as well as the whole flame images are captured and discussed. Traditional photography techniques are adopted to illustrate the dimensional characteristics of every flame mode. The central jet oscillations are diagnosed by a two component laser Doppler anemometer. Combined images of the flame and flow are gathered using the laser-light sheet assisted Mie scattering method. Results showed that the short and wide flame which was induced during acoustic forcing is principally because of the severe premixing at the tip of the burner tube. Wake recirculation bubble enhanced premixing at low swirl number while it damped the jet oscillation at higher swirl number. Mechanics of mixing at every flame mode during acoustic excitation are reported and discussed.

Keywords

Reacting swirling wakeAcoustic excitationNon-premixed flameJet oscillations.
Type
Articles
Information
Journal of Mechanics , Volume 26 , Issue 3 , September 2010 , pp. 279 - 286
Copyright
Copyright © The Society of Theoretical and Applied Mechanics, R.O.C. 2010

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1.Gupta, A. K., Lilley, D. G. and Syred, N, Swirl Flows, Abacus Press, Cambridge, USA, pp. 13–117 (1984).Google Scholar
2.Sheen, H. J., Chen, W. J. and Jeng, S. Y., “Recirculation Zones of Unconfined and Confined Annular Swirling Jets,” American Institute of Aeronautics and Astronautics Journal, 34, pp. 572–579 (1996).Google Scholar
3.Huang, R. F. and Tsai, F. C, “Observations of Swirling Flows Behind Circular Discs,” American Institute of Aeronautics and Astronautics Journal, 39, pp. 1106–1112(2001).Google Scholar
4.Huang, R. F. and Yen, S. C, “Aerodynamic Characteristics and Thermal Structure of Non-premixed Reacting Swirling Wakes at Low Reynolds Numbers,” Combust. Flame, 155, pp. 539–556 (2008).Google Scholar
5.Kim, T. K., Park, J. and Shih, H. D., “Mixing Mechanism Near the Nozzle Exit in a Tone Excited Nonpremixed Jet Flame,” Combustion Science and Technology, 89, pp. 83–100 (1993).Google Scholar
6.Baillot, F and Demare, D., “Physical Mechanisms of Lifted Non-premixed Flame Stabilized in an Acoustic Field,” Combustion Science and Technology, 174, pp. 73–98 (2002).Google Scholar
7.Lakshminarasimhan, K., Ryan, M. D., Clemens, N. T. and Ezekoye, O. A., “Mixing Characteristics in Strongly Forced Non-premixed Methane Jet Flames,” Proceedings Combustion Institute, 31, pp. 1617–1624 (2007).Google Scholar
8.Lee, K. M, Kim, T. K., Kim, W. J., Kim, S. G., Park, J. and Keel, S. N, “A Visual Study on Flame Behavior in Tone-excited Non-premixed Jet Flames,” Fuel, 81, pp. 2249–2255 (2002).Google Scholar
9.Pan, K. L., “Flame Propagation with Hydrodynamic Instability in Vortical Flows,” Journal of Mechanics 24, pp.277–284 (2008).Google Scholar
10.Chao, Y. C, Wu, C. Y., Yuan, T. and Cheng, T. S., “Stabilization Process of a Lifted Flame Tuned by Acoustic Excitation,” Combustion Science and Technology, 174, pp. 87–110(2002).Google Scholar
11.Wu, C. Y., Chao, Y. C, Cheng, T. S., Li, Y. H., Lee, K. Y. and Yuan, T., “The Blowout Mechanism of Turbulent Jet Diffusion Flames,” Combust. Flame, 145, pp. 481–494 (2006).Google Scholar
12.Chao, Y. C, Yuan, T. and Tseng, C. S., “Effects of Flame Lifting and Acoustic Excitation on the Reduction of NOx Emissions,” Combustion Science and Technology, 113, pp. 49–65(1996).Google Scholar
13.Demare, D. and Baillot, F., “Acoustic Enhancement of Combustion in Lifted Non-premixed Jet Flames,” Combust. Flame, 139, pp. 312–328 (2004).Google Scholar
14.Ginevsky, A. S., Vlasov, Y. V. and Karavosov, R. K., Acoustic Control of Turbulent Jets, Springer-Verlag Berlin Heidelberg, pp. 33–99 (2004).Google Scholar
15.Kinsler, L. E. and Frey, A. R., Fundamentals of Acoustics 2nd Ed., Wiley, pp. 247–293, New York (1982).Google Scholar
16.Hjelmfelt, A. T. and Mockros, L. F., “Motion of Discrete Particles in a Turbulent Fluid,” Applied Science Research, 16, pp. 149–154(1966).Google Scholar
17.Fujii, S. and Eguchi, K., “Comparison of Cold and Reacting Flows Around a Bluff-body Flame Stabilizer,” Journal of Fluids Engineering, Transactions of ASME, 103, pp. 328–334(1981).Google Scholar
18.Eaton, A. R, Frey, S. F., Cusano, D. M., Plesniak, M. W. and Sojka, P. E., “Development of a Full-field Planar Mei Scattering Technique for Evaluating Swirling Mixers,” Experiments inFluids, 21, pp. 325–330 (1996).Google Scholar