Intermittency in premixed reacting flows is studied using numerical simulations of premixed flames at a range of turbulence intensities. The flames are modeled using a simplified reaction mechanism that represents a stoichiometric H2-air mixture. Intermittency is associated with high probabilities of large fluctuations in flow quantities, and these fluctuations can have substantial effects on the evolution and structure of premixed flames. Intermittency is characterized here using probability density functions (pdfs) and moments of the local enstrophy, pseudo-dissipation rate (strain rate magnitude), and scalar (reactant mass fraction) dissipation rate. Simulations of homogeneous isotropic turbulence with a nonreacting passive scalar are also carried out in order to provide a baseline for analyzing the reacting flow results. In the reacting flow simulations, conditional analyses based on local, instantaneous values of the scalar are used to study variations in the pdfs, moments, and intermittency through the flame. For low intensities, pdfs of the local enstrophy vary substantially through the flame, with greater intermittency near the products. Changes in the pseudo-dissipation pdfs are, however, less pronounced. As the intensity increases, both the enstrophy and pseudo-dissipation pdfs become increasingly independent of position in the flame and are similar to results from the nonreacting simulations. The scalar dissipation intermittency is largest near the reactants and increases at all flame locations with increasing turbulence intensity. For low intensities and in the reaction zone, however, scalar dissipation pdfs approximately follow a Gaussian distribution, indicative of substantially reduced intermittency. Deviations from log-normality are observed in the pdfs of all quantities, even for intensities and flame locations characterized by strong intermittency. The implications of these results for the internal structure of the flame are discussed, and we also propose a connection between reacting flow intermittency and anisotropic vorticity suppression by the flame.

1.
L. K.
Su
and
W. J. A.
Dahm
, “
Scalar imaging velocimetry measurements of the velocity gradient tensor field in turbulent flows. II. Experimental results
,”
Phys. Fluids
8
,
1883
1906
(
1996
).
2.
B. W.
Zeff
,
D. D.
Lanterman
,
R.
McAllister
,
E. J.
Kostellich
R.
Roy
, and
D. P.
Lathrop
, “
Measuring intense rotation and dissipation in turbulent flows
,”
Nature (London)
421
,
146
149
(
2003
).
3.
C. N.
Markides
and
E.
Mastorakos
, “
Measurements of the statistical distribution of the scalar dissipation rate in turbulent axisymmetric plumes
,”
Flow, Turbul. Combust.
81
,
221
234
(
2008
).
4.
R. S.
Miller
,
F. A.
Jaberi
,
C. K.
Madnia
, and
P.
Givi
, “
The structure and small-scale intermittency of passive scalars in homogeneous turbulence
,”
J. Sci. Comput.
10
,
151
180
(
1995
).
5.
M. R.
Overholt
and
S. B.
Pope
, “
Direct numerical simulation of a passive scalar with imposed mean gradient in isotropic turbulence
,”
Phys. Fluids
8
(
11
),
3128
3148
(
1996
).
6.
P.
Vedula
,
P. K.
Yeung
, and
R. O.
Fox
, “
Dynamics of scalar dissipation in isotropic turbulence: a numerical and modelling study
,”
J. Fluid Mech.
433
,
29
60
(
2001
).
7.
J.
Schumacher
,
K. R.
Sreenivasan
, and
P. K.
Yeung
, “
Very fine structures in scalar mixing
,”
J. Fluid Mech.
531
,
113
122
(
2005
).
8.
D. A.
Donzis
,
P. K.
Yeung
, and
K. R.
Sreenivasan
, “
Dissipation and enstrophy in isotropic turbulence: Resolution effects and scaling in direct numerical simulations
,”
Phys. Fluids
20
,
045108
(
2008
).
9.
D. A.
Donzis
and
P. K.
Yeung
, “
Resolution effects and scaling in numerical simulations of passive scalar mixing in turbulence
,”
Physica D
239
,
1278
1287
(
2010
).
10.
U.
Frisch
,
Turbulence: The Legacy of A.N. Kolmogorov
(
Cambridge University Press
,
1995
).
11.
K. R.
Sreenivasan
, “
Possible effects of small-scale intermittency in turbulent reacting flows
,”
Flow, Turbul. Combust.
72
,
115
131
(
2004
).
12.
P. A.
Davidson
,
Turbulence: An Introduction for Scientists and Engineers
(
Oxford University Press
,
2004
).
13.
A.
Tsinober
,
An Informal Conceptual Introduction to Turbulence
(
Springer
,
2009
).
14.
L. K.
Su
and
N. T.
Clemens
, “
The structure of fine-scale scalar mixing in gas-phase planar turbulent jets
,”
J. Fluid Mech.
488
,
1
29
(
2003
).
15.
T.
Boeck
,
D.
Krasnov
, and
J.
Schumacher
, “
Statistics of velocity gradients in wall-bounded shear flow turbulence
,”
Physica D
239
,
1258
1263
(
2010
).
16.
P. E.
Hamlington
,
D.
Krasnov
,
T.
Boeck
, and
J.
Schumacher
, “
Statistics of the energy dissipation rate and local enstrophy in turbulent channel flow
,”
Physica D
241
,
169
177
(
2012
).
17.
G.
Samanta
,
K. D.
Housiadas
,
R. A.
Handler
, and
A. N.
Beris
, “
Effects of viscoelasticity on the probability density functions in turbulent channel flow
,”
Phys. Fluids
21
,
115106
(
2009
).
18.
P. E.
Hamlington
,
D.
Krasnov
,
T.
Boeck
, and
J.
Schumacher
, “
Local dissipation scales and energy dissipation-rate moments in channel flow
,”
J. Fluid Mech.
701
,
419
429
(
2012
).
19.
R. W.
Bilger
, “
Some aspects of scalar dissipation
,”
Flow, Turbul. Combust.
72
,
93
114
(
2004
).
20.
R. W.
Bilger
, “
Turbulent jet diffusion flames
,”
Prog. Energy Combust. Sci.
1
,
87
109
(
1976
).
21.
K. N. C.
Bray
, in
Turbulent Reacting Flows
, edited by
P. A.
Libby
and
F. A.
Williams
(
Springer-Verlag
,
New York
,
1980
).
22.
P. E.
Hamlington
,
A. Y.
Poludnenko
, and
E. S.
Oran
, “
Interactions between turbulence and flames in premixed reacting flows
,”
Phys. Fluids
23
,
125111
(
2011
).
23.
N.
Swaminathan
and
K. N. C.
Bray
, “
Effect of dilatation on scalar dissipation in turbulent premixed flames
,”
Combust. Flame
143
,
549
565
(
2005
).
24.
A. Y.
Poludnenko
and
E. S.
Oran
, “
The interaction of high-speed turbulence with flames: Global properties and internal flame structure
,”
Combust. Flame
157
,
995
1011
(
2010
).
25.
A. R.
Kerstein
, “
Turbulence in combustion processes: modeling challenges
,”
Proc. Combust. Inst.
29
,
1763
1773
(
2002
).
26.
L.
Pan
,
J. C.
Wheeler
, and
J.
Scalo
, “
The effect of turbulent intermittency on the deflagration to detonation transition in supernova Ia explosions
,”
Astrophys. J.
681
,
470
481
(
2008
).
27.
A. N.
Karpetis
and
R. S.
Barlow
, “
Measurements of scalar dissipation in a turbulent piloted methane/air jet flame
,”
Proc. Combust. Inst.
29
,
1929
1936
(
2002
).
28.
E. R.
Hawkes
,
R.
Sankaran
,
J. C.
Sutherland
, and
J. H.
Chen
, “
Scalar mixing in direct numerical simulations of temporally evolving plane jet flames with skeletal CO/H2 kinetics
,”
Proc. Combust. Inst.
31
,
1633
1640
(
2007
).
29.
D. O.
Lignell
,
J. H.
Chen
, and
H. A.
Schmutz
, “
Effects of Damköhler number on flame extinction and reignition in turbulent non-premixed flames using DNS
,”
Combust. Flame
158
,
949
963
(
2011
).
30.
C.
Pantano
,
S.
Sarkar
, and
F.
Williams
, “
Mixing of a conserved scalar in a turbulent reacting shear layer
,”
J. Fluid Mech.
481
,
291
328
(
2003
).
31.
S. H.
Starner
,
R. W.
Bilger
,
M. B.
Long
,
J. H.
Frank
, and
D. F.
Marran
, “
Scalar dissipation measurements in turbulent jet diffusion flames of air diluted methane and hydrogen
,”
Combust. Sci. Tech.
129
,
141
163
(
1997
).
32.
Y.-C.
Chen
and
M.
Mansour
, “
Measurements of scalar dissipation in turbulent hydrogen diffusion flames and some implications on combustion modeling
,”
Combust. Sci. Tech.
126
,
291
313
(
1997
).
33.
A. M.
Oboukhov
, “
Some specific features of atmospheric turbulence
,”
J. Fluid Mech.
13
,
77
81
(
1962
).
34.
A. N.
Kolmogorov
, “
A refinement of previous hypotheses concerning the local structure of turbulence of a viscous incompressible fluid at high Reynolds number
,”
J. Fluid Mech.
13
,
82
85
(
1962
).
35.
S. B.
Pope
,
Turbulent Flows
(
Cambridge University Press
,
2000
).
36.
T.
Poinsot
and
D.
Veynante
,
Theoretical and Numerical Combustion
(
Edwards
,
2005
).
37.
E.
Effelsberg
and
N.
Peters
, “
Scalar dissipation rates in turbulent jets and jet diffusion flames
,”
Symp. (Int.) Combust.
22
(
1
),
693
700
(
1989
).
38.
M. R.
Overholt
and
S. B.
Pope
, “
Direct numerical simulation of a statistically stationary, turbulent reacting flow
,”
Combust. Theor. Model.
3
,
371
408
(
1999
).
39.
V. N.
Gamezo
,
T.
Ogawa
, and
E. S.
Oran
, “
Flame acceleration and DDT in channels with obstacles: effect of obstacle spacing
,”
Combust. Flame
155
,
302
315
(
2008
).
40.
P. E.
Hamlington
,
A. Y.
Poludnenko
, and
E. S.
Oran
, “
Turbulence and scalar gradient dyanmics in premixed reacting flows
,” AIAA Paper, 2010–5027,
2010
.
41.
P. E.
Hamlington
,
A. Y.
Poludnenko
, and
E. S.
Oran
, “
Intermittency and premixed turbulent reacting flows
,” AIAA Paper 2011–113,
2011
.
42.
A. Y.
Poludnenko
and
E. S.
Oran
, “
The interaction of high-speed turbulence with flames: turbulent flame speed
,”
Combust. Flame
158
,
301
326
(
2011
).
43.
T. A.
Gardiner
and
J. M.
Stone
, “
An unsplit Godunov method for ideal MHD via constrained transport in three dimensions
,”
J. Comp. Phys.
227
,
4123
4141
(
2008
).
44.
P.
Colella
, “
Multidimensional upwind methods for hyperbolic conservation-laws
,”
J. Comp. Physiol.
87
,
171
200
(
1990
).
45.
J.
Saltzman
, “
An unsplit 3D upwind method for hyperbolic conservation-laws
,”
J. Comp. Physiol.
115
,
153
168
(
1994
).
46.
N.
Peters
,
Turbulent Combustion
(
Cambridge
,
2000
).
47.
J. P.
Boris
, in
Whither Turbulence? Turbulence at the Crossroads
, edited by
J. L.
Lumley
(
Springer-Verlag
,
New York
,
1990
).
48.
W. J.
Rider
,
F. F.
Grinstein
, and
L. G.
Margolin
,
Implicit Large Eddy Simulation
(
Cambridge University Press
,
2007
).
49.
R.
Benzi
,
L.
Biferale
,
R. T.
Fisher
,
L. P.
Kadanoff
,
D. Q.
Lamb
, and
F.
Toschi
, “
Intermittency and universality in fully developed inviscid and weakly compressible turbulent flows
,”
Phys. Rev. Lett.
100
,
234503
(
2008
).
50.
D.
Porter
,
A.
Pouquet
, and
P.
Woodward
, “
Measures of intermittency in driven supersonic flows
,”
Phys. Rev. E
66
,
026301
(
2002
).
51.
H.
Tennekes
, “
Intermittency of the small-scale structure of atmospheric turbulence
,”
Boundary Layer Meteorol.
4
,
241
250
(
1973
).
52.
C. J.
Mueller
,
J. F.
Driscoll
,
D. L.
Reuss
,
M. C.
Drake
, and
M. E.
Rosalik
, “
Vorticity generation and attenuation as vortices convect through a premixed flame
,”
Combust. Flame
112
,
342
358
(
1998
).
53.
P. A.
McMurtry
,
J. J.
Riley
, and
R. W.
Metcalfe
, “
Effects of heat release on the large-scale structure in turbulent mixing layers
,”
J. Fluid Mech.
199
,
297
332
(
1989
).
54.
A. N.
Lipatnikov
and
J.
Chomiak
, “
Effects of premixed flames on turbulence and turbulence scalar transport
,”
Prog. Energy Combust. Sci.
36
,
1
202
(
2010
).
55.
N.
Swaminathan
and
R. W.
Grout
, “
Interaction of turbulence and scalar fields in premixed flames
,”
Phys. Fluids
18
,
045102
(
2006
).
56.
S. H.
Kim
and
H.
Pitsch
, “
Scalar gradient and small-scale structure in turbulent premixed combustion
,”
Phys. Fluids
19
,
115104
(
2007
).
57.
N.
Chakraborty
and
N.
Swaminathan
, “
Influence of the Damköhler number on turbulence-scalar interaction in premixed flames. I. Physical insight
,”
Phys. Fluids
19
,
045103
(
2007
).
58.
G.
Hartung
,
J.
Hult
,
C. F.
Kaminski
,
J. W.
Rogerson
, and
N.
Swaminathan
, “
Effect of heat release on turbulence and scalar-turbulence interaction in premixed combustion
,”
Phys. Fluids
20
,
035110
(
2008
).
59.
M.
Tanahashi
,
M.
Fujimura
, and
T.
Miyauchi
, “
Coherent fine-scale eddies in turbulent premixed flames
,”
Proc. Combust. Inst.
28
,
529
535
(
2000
).
60.
A. B.
Zel'Dovich
,
A. G.
Istratov
,
N. I.
Kidin
, and
V. B.
Librovich
, “
Flame propagation in tubes: Hydrodynamics and stability
,”
Comb. Sci. Tech.
24
,
1
13
(
1980
).
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