A visual study on turnabout phenomenon of vortex roll-up in forced jet diffusion flames

Fluids Engineering


An experimental study on the effect of forcing amplitude in forced jet diffusion flames has been conducted. Various flow visualization techniques are employed using optical schemes, including light scattering photography, high speed imaging by motion analysis, and determination of velocity vector and vorticity fields from PIV data. Particular attenttion is focused on the turnabout mechanism around the elongated flame, which has not been reported previously, and on the inner coherent structure of the forced jet in the attached flame regime. In particular, we present a schematic diagram that aids in the understanding of the turnabout mechanism of vortex roll-up. This diagram explains why the forced flame is elongated under moderate forcing amplitudes but shortens again when the forcing amplitude is further increased.


Coherent structure behavior Elongated flame Fluctuating velocity Forced jet flame Forcing amplitude In-burning flame Phase synchronization Turnout of vortex roll-up 


  1. [1]
    A. J. Yule, Large-scale structure in the mixing layer of a round jet,J. Fluid Mech. 89 (1978) 413.CrossRefGoogle Scholar
  2. [2]
    A. K. M. F. Hussain, Coherent structures and turbulence,J. Fluid Mech. 173 (1986) 303.CrossRefGoogle Scholar
  3. [3]
    P. J. Vermeulen, V. Ramesh and W. K. Yu, Measurement of entrainment by acoustically pulsed axisymmetric air jets,J. of Engineering for Gas Turbines and Powers 108 (1986) 479.CrossRefGoogle Scholar
  4. [4]
    W. S. Anthony and J. C. Brain, Visualization of the structure of a pulsed methane-air diffusion flame,Phys. Fluids. 28, (1985) 2317.CrossRefGoogle Scholar
  5. [5]
    L. G. Pearson, A. Gabelli, I. G. Shepherd and N. B. Hamilton, Structure in diffusion flames an accoustic viewpoint, Joint International Conference Australia/ New Zealand and Japanese Section of the Combustion Institute, Sydney, (1989) 24.Google Scholar
  6. [6]
    E. Gutmak, T. P. Parr, D. M. Hanson-Parr and K. C. Schadow, Planar imaging of vortex dynamics in flames,J. of Heat Transfer. 111 (1989) 148.CrossRefGoogle Scholar
  7. [7]
    T. K. Kim, J. Park and H. D. Shin, Mixing mechanism near the nozzle exit in a tone excited nonpremixed jet flame,Combustion Science and technology 89 (1993) 83.CrossRefGoogle Scholar
  8. [8]
    K. M. Lee, S. K. Oh and J. Park, A visual investigation of coherent structure behavior under toneexcited laminar non-premixed jet flame,J. of KSME B. 27 (2003) 275.Google Scholar
  9. [9]
    S. G. Kim, K. T. Kim and J. Park, An experimental study on the lift-off behavior of tone-excited propane non-premixed jet flames,J. of KSME B. 28 (2004) 569.Google Scholar
  10. [10]
    S. K. Oh, An experimental study on the structure of forced jet and jet diffusion flames, Ph. D. Thesis, KAIST, Taejeon, (2001).Google Scholar

Copyright information

© The Korean Society of Mechanical Engineers (KSME) 2007

Authors and Affiliations

  1. 1.School of Mechanical and Aerospace EngineeringSunchon National UniversityJeonnamKorea

Personalised recommendations