Abstract
Digital image analysis of cine pictures of an unconfined rich premixed turbulent flame has been used to determine structural characteristics of the turbulent/non-turbulent interface of the flame. The results, comprising various moments of the interface position, probability density functions and correlation functions, establish that the instantaneous flame-interface position is essentially a Gaussian random variable with a superimposed quasi-periodical component. The latter is ascribable to a pulsation caused by the convection and the stretching of ring vortices present within the flame. To a first approximation, the flame can be considered similar to a three-dimensional axisymmetric turbulent jet, with superimposed ring vortices, in which combustion occurs.
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Abbreviations
- A :
-
amplitude (mm)
- D :
-
burner inside diameter (mm)
- F :
-
flatness factor
- f :
-
frequency (Hz)
- I :
-
indicator function
- j :
-
frame number
- k :
-
slit (column or row) number
- N :
-
number of frames
- p :
-
probability density function
- R :
-
auto/cross-correlation (mm2)
- Re :
-
Reynolds number
- S :
-
skewness factor
- St :
-
Strouhal number
- s :
-
spread (mm)
- T :
-
period (s) or sampling time (s)
- t :
-
time (s)
- U :
-
velocity (m/s)
- u :
-
reference variable (mm)
- V :
-
convection velocity (m/s)
- v :
-
reference variable (mm)
- w :
-
instantaneous generalized coordinate (mm)
- X :
-
instantaneous streamwise interface position (mm)
- x :
-
streamwise coordinate (mm)
- Y :
-
instantaneous lateral interface position (mm)
- y :
-
lateral coordinate (mm)
- Z :
-
instantaneous generalized interface position (mm)
- z :
-
Gaussian random variable
- Δ :
-
difference
- Δ :
-
time interval between movie frames (s)
- α :
-
angle (degree)
- ρ :
-
normalized auto/cross/correlation function
- σ :
-
standard deviation (mm)
- τ :
-
time lag (s)
- ζ :
-
phase (radian)
- l :
-
lower edge
- o :
-
Gaussian component
- s :
-
periodic component
- t :
-
tip edge
- u :
-
upper edge
- 1:
-
minimum value
- 2:
-
maximum value
- ′:
-
root-mean-square
- -:
-
time-average
- *:
-
threshold/reference value
References
Bendat, J. S.; Piersol, A. G. 1979: Random data-analysis and measurement procedures, pp. 170–183. New York: Wiley-Interscience
Fox, M. D.; Weinberg, F. J. 1962: An experimental study of burner-stabilised flames in premixed reactants. Proc. R. Soc. London. Ser. A268, 222–239
Glassman I. 1977: Combustion, pp. 107–113. London: Academic Press
Hurle, I. R.; Price, R. B.; Sugden, T. M.; Thomas, A. 1968: Sound emission from open turbulent premixed flames. Proc. R. Soc. London. Ser. A303, 409–427
Hussain, A. K. M. F. 1981: The prefered mode of the axisymmetric jet. J. Fluid Mech. 110, 39–71
Rosenfeld, A.; Kak, A. V. 1982: Digital picture processing, vol. 2, pp. 84–86. London: Academic Press
Shokr, M.; Keffer, J. F. 1983: Digital image analysis of a complex turbulent wake. In: Structure of complex turbulent shear flow (eds. Dumas, R.; Fulachier, L.), pp. 165–174. Berlin, Heidelberg, New York: Springer
Shokr, M.; Keffer, J. F.; Kawall, J. G. 1985: Structural features of the near region of an asymmetric turbulent wake. In: Turbulent shear flows 4 (eds. Bradbury, L. J. S.; Durst, F.; Launder, B. F.; Schmidt, F. W.; Whitelaw, J. H.), pp. 182–191. Berlin, Heidelberg, New York: Springer
Zucherman, L. 1985: Preliminary study of turbulent flames using digital image processing. M.A.Sc. Thesis, University of Toronto
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Zucherman, L., Kawall, J.G. & Keffer, J.F. Digital image analysis of a turbulent flame. Experiments in Fluids 6, 16–24 (1988). https://doi.org/10.1007/BF00226130
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DOI: https://doi.org/10.1007/BF00226130