Deep artificial neural networks (ANNs) are used for modeling sub-grid scale mixing quantities such as the filtered density function (FDF) of the mixture fraction and the conditional scalar dissipation rate. A deep ANN with four hidden layers is trained with carrier-phase direct numerical simulations (CP-DNS) of turbulent spray combustion. A priori validation corroborates that ANN predictions of the mixture fraction FDF and the conditional scalar dissipation rate are in very good agreement with CP-DNS data. ANN modeled solutions show much better performance with a mean error of around 1%, which is one order of magnitude smaller than that of standard modeling approaches such as the β-FDF and its modified version. The predicted conditional scalar dissipation rate agrees very well with CP-DNS data over the entire mixture fraction space, whereas conventional models derived for pure gas phase combustion fail to describe ⟨N|ξ = η⟩ in regions with higher mixture fraction and low probability. In the second part of this paper, uncertainties associated with ANN predictions are analyzed. It is shown that a suitable selection of training sets can reduce the size of the necessary test database by ∼50% without compromising the accuracy. Feature importance analysis is used to analyze the importance of different combustion model parameters. While the droplet evaporating rate, the droplet number density, and the mixture fraction remain the dominant features, the influence of turbulence related parameters only becomes important if turbulence levels are sufficiently high.

1.
P.
Jenny
,
D.
Roekaerts
, and
N.
Beishuizen
, “
Modeling of turbulent dilute spray combustion
,”
Prog. Combust. Sci. Technol.
38
,
846
887
(
2012
).
2.
S.
Sreedhara
and
K. Y.
Huh
, “
Conditional statistics of nonreacting and reacting sprays in turbulent flows by direct numerical simulation
,”
Proc. Combust. Inst.
31
,
2335
2342
(
2007
).
3.
H.
Wang
,
K.
Luo
, and
J.
Fan
, “
Direct numerical simulation and CMC (conditional moment closure) sub-model validation of spray combustion
,”
Energy
46
,
606
617
(
2012
).
4.
S.
Ukai
,
A.
Kronenburg
, and
O. T.
Stein
, “
Large eddy simulation of dilute acetone spray flames using CMC coupled with tabulated chemistry
,”
Proc. Combust. Inst.
35
,
1667
1674
(
2015
).
5.
M. P.
Sitte
and
E.
Mastorakos
, “
Modelling of spray flames with doubly conditional moment closure
,”
Flow, Turbul. Combust.
99
,
933
954
(
2017
).
6.
N.
Peters
,
Turbulent Combustion
(
Cambridge University Press
,
2000
).
7.
M.
Chrigui
,
J.
Gounder
,
A.
Sadiki
,
A. R.
Masri
, and
J.
Janicka
, “
Partially premixed reacting acetone spray using LES and FGM tabulated chemistry
,”
Combust. Flame
159
,
2718
2741
(
2012
).
8.
S.
De
and
S. H.
Kim
, “
Large eddy simulation of dilute reacting sprays: Droplet evaporation and scalar mixing
,”
Combust. Flame
160
,
2048
2066
(
2013
).
9.
A.
Rittler
,
L.
Deng
,
I.
Wlokas
, and
A. M.
Kempf
, “
Large eddy simulations of nanoparticle synthesis from flame spray pyrolysis
,”
Proc. Combust. Inst.
36
,
1077
1087
(
2017
).
10.
Y.
Hu
and
R.
Kurose
, “
Nonpremixed and premixed flamelets LES of partially premixed spray flames using a two-phase transport equation of progress variable
,”
Combust. Flame
188
,
227
242
(
2018
).
11.
P.
Domingo-Alvarez
,
P.
Bénard
,
V.
Moureau
,
G.
Lartigue
, and
F.
Grisch
, “
Impact of spray droplet distribution on the performances of a kerosene lean/premixed injector
,”
Flow, Turbul. Combust.
104
,
421
450
(
2020
).
12.
S.
Navarro-Martinez
,
A.
Kronenburg
, and
F.
Di Mare
, “
Conditional moment closure for large eddy simulations
,”
Flow, Turbul. Combust.
75
,
245
274
(
2005
).
13.
V.
Raman
,
H.
Pitsch
, and
R.
Fox
, “
Hybrid large-eddy simulation/Lagrangian filtered-density-function approach for simulating turbulent combustion
,”
Combust. Flame
143
,
56
78
(
2005
).
14.
A.
Triantafyllidis
and
E.
Mastorakos
, “
Implementation issues of the conditional moment closure model in large eddy simulations
,”
Flow, Turbul. Combust.
84
,
481
512
(
2010
).
15.
M.
Ihme
and
H.
Pitsch
, “
Prediction of extinction and reignition in nonpremixed turbulent flames using a flamelet/progress variable model: 2. Application in LES of sandia flames D and E
,”
Combust. Flame
155
,
90
107
(
2008
).
16.
H.-W.
Ge
and
E.
Gutheil
, “
Probability density function (PDF) simulation of turbulent spray flows
,”
Atomisation Sprays
16
,
531
542
(
2006
).
17.
H.-W.
Ge
and
E.
Gutheil
, “
Simulation of a turbulent spray flame using coupled PDF gas phase and spray flamelet modeling
,”
Combust. Flame
153
,
173
185
(
2008
).
18.
E.
Madadi-Kandjani
,
R. O.
Fox
, and
A.
Passalacqua
, “
Application of the Fokker-Planck molecular mixing model to turbulent scalar mixing using moment methods
,”
Phys. Fluids
29
,
065109
(
2017
).
19.
N.
Kim
,
K.
Jung
, and
Y.
Kim
, “
Multi-environment pdf modeling for n-dodecane spray combustion processes using tabulated chemistry
,”
Combust. Flame
192
,
205
220
(
2018
).
20.
E. E.
O’Brien
and
T. L.
Jiang
, “
The conditional dissipation rate of an initially binary scalar in homogeneous turbulence
,”
Phys. Fluids A
3
,
3121
3123
(
1991
).
21.
I. S.
Kim
and
E.
Mastorakos
, “
Simulations of turbulent non-premixed counterflow flames with first-order conditional moment closure
,”
Flow, Turbul. Combust.
76
,
133
162
(
2006
).
22.
A. J. M.
Buckrell
and
C. B.
Devaud
, “
Investigation of mixing models and conditional moment closure applied to autoignition of hydrogen jets
,”
Flow, Turbul. Combust.
90
,
621
644
(
2013
).
23.
A.
Garmory
and
E.
Mastorakos
, “
Capturing localised extinction in sandia flame F with LES-CMC
,”
Proc. Combust. Inst.
33
,
1673
1680
(
2011
).
24.
S. S.
Girimaji
, “
On the modeling of scalar diffusion in isotropic turbulence
,”
Phys. Fluids A
4
,
2529
2537
(
1992
).
25.
V.
Eswaran
and
S. B.
Pope
, “
Direct numerical simulations of the turbulent mixing of a passive scalar
,”
Phys. Fluids
31
,
506
520
(
1988
).
26.
S. B.
Pope
, “
Mapping closures for turbulent mixing and reaction
,”
Theor. Comput. Fluid Dyn.
2
,
255
270
(
1991
).
27.
A.
Kronenburg
,
R. W.
Bilger
, and
J. H.
Kent
, “
Computation of conditional average scalar dissipation in turbulent jet diffusion flames
,”
Flow, Turbul. Combust.
64
,
145
159
(
2000
).
28.
C. B.
Devaud
,
R. W.
Bilger
, and
T.
Liu
, “
A new method of modeling the conditional scalar dissipation rate
,”
Phys. Fluids
16
,
2004
2011
(
2004
).
29.
A. Y.
Klimenko
and
S. B.
Pope
, “
The modelling of turbulent reacting flows based on multiple mapping conditioning
,”
Phys. Fluids
15
(
7
),
1907
1925
(
2003
).
30.
P.
Vaishnavi
and
A.
Kronenburg
, “
Multiple mapping conditioning of velocity in turbulent jet flames
,”
Combust. Flame
157
,
1863
1865
(
2010
).
31.
K.
Vogiatzaki
,
A.
Kronenburg
,
M. J.
Cleary
, and
J. H.
Kent
, “
Multiple mapping conditioning of turbulent jet diffusion flames
,”
Proc. Combust. Inst.
32
,
1679
1685
(
2009
).
32.
K.
Vogiatzaki
,
M. J.
Cleary
,
A.
Kronenburg
, and
J. H.
Kent
, “
Modeling of scalar mixing in turbulent jet flames by multiple mapping conditioning
,”
Phys. Fluids
21
,
025105
(
2009
).
33.
J.
Réveillon
and
L.
Vervisch
, “
Spray vaporization in nonpremixed turbulent combustion modeling: A single droplet model
,”
Combust. Flame
121
,
75
90
(
2000
).
34.
A. Y.
Klimenko
and
R. W.
Bilger
, “
Conditional moment closure for turbulent combustion
,”
Prog. Energy Combust. Sci.
25
,
595
688
(
1999
).
35.
B.
Wang
,
A.
Kronenburg
, and
O. T.
Stein
, “
A new perspective on modelling passive scalar conditional mixing statistics in turbulent spray flames
,”
Combust. Flame
208
,
376
387
(
2019
).
36.
J.
Seo
and
K. Y.
Huh
, “
Analysis of combustion regimes and conditional statistics of autoigniting turbulent n-heptane sprays
,”
Proc. Combust. Inst.
33
,
2127
2134
(
2011
).
37.
Y. M.
Wright
,
G.
DePaola
,
K.
Boulouchos
, and
E.
Mastorakos
, “
Simulations of spray autoignition and flame establishment with two-dimensional CMC
,”
Combust. Flame
143
,
402
419
(
2005
).
38.
G.
Borghesi
,
E.
Mastorakos
, and
R. S.
Cant
, “
Complex chemistry DNS of n-heptane spray autoignition at high pressure and intermediate temperature conditions
,”
Combust. Flame
160
,
1254
1275
(
2013
).
39.
M.
Ihme
,
C.
Schmitt
, and
H.
Pitsch
, “
Optimal artificial neural networks and tabulation methods for chemistry representation in LES of a bluff-body swirl-stabilized flame
,”
Proc. Combust. Inst.
32
,
1527
1535
(
2009
).
40.
A. K.
Chatzopoulos
and
S.
Rigopoulos
, “
A chemistry tabulation approach via rate-controlled constrained equilibrium (RCCE) and artificial neural networks (ANNs), with application to turbulent non-premixed CH4/H2/N2 flames
,”
Proc. Combust. Inst.
34
,
1465
1473
(
2013
).
41.
L. L. C.
Franke
,
A. K.
Chatzopoulos
, and
S.
Rigopoulos
, “
Tabulation of combustion chemistry via artificial neural networks (ANNs): Methodology and application to LES-PDF simulation of Sydney Flame L
,”
Combust. Flame
185
,
245
260
(
2017
).
42.
R.
Ranade
,
G.
Li
,
S.
Li
, and
T.
Echekki
, “
An efficient machine-learning approach for PDF tabulation in turbulent combustion closure
,”
Combust. Sci. Technol.
2019
,
1
20
.
43.
O.
Owoyele
,
P.
Kundu
,
M. M.
Ameen
,
T.
Echekki
, and
S.
Som
, “
Application of deep artificial neural networks to multi-dimensional flamelet libraries and spray flames
,”
Int. J. Engine Res.
21
,
151
168
(
2020
).
44.
A.
Seltz
,
P.
Domingo
,
L.
Vervisch
, and
Z. M.
Nikolaou
, “
Direct mapping from LES resolved scales to filtered-flame generated manifolds using convolutional neural networks
,”
Combust. Flame
210
,
71
82
(
2019
).
45.
J.
Xing
,
K.
Luo
,
H.
Pitsch
,
H.
Wang
,
Y.
Bai
,
C.
Zhao
, and
J.
Fan
, “
Predicting kinetic parameters for coal devolatilization by means of artificial neural networks
,”
Proc. Combust. Inst.
37
,
2943
2950
(
2019
).
46.
M.
Gamahara
and
Y.
Hattori
, “
Searching for turbulence models by artificial neural network
,”
Phys. Rev. Fluids
2
,
054604
(
2017
).
47.
Z.
Wang
,
K.
Luo
,
D.
Li
,
J.
Tan
, and
J.
Fan
, “
Investigations of data-driven closure for subgrid-scale stress in large-eddy simulation
,”
Phys. Fluids
30
,
125101
(
2018
).
48.
J.
Ling
,
A.
Kurzawski
, and
J.
Templeton
, “
Reynolds averaged turbulence modelling using deep neural networks with embedded invariance
,”
J. Fluid Mech.
807
,
155
166
(
2016
).
49.
J.
Ling
and
J.
Templeton
, “
Evaluation of machine learning algorithms for prediction of regions of high Reynolds averaged Navier–Stokes uncertainty
,”
Phys. Fluids
27
,
085103
(
2015
).
50.
M.
Bode
,
M.
Gauding
,
K.
Kleinheinz
, and
H.
Pitsch
, “
Deep learning at scale for subgrid modeling in turbulent flows
,” arXiv:1910.00928 (
2019
).
51.
A.
Moreau
,
O.
Teytaud
, and
J. P.
Bertoglio
, “
Optimal estimation for large-eddy simulation of turbulence and application to the analysis of subgrid models
,”
Phys. Fluids
18
,
105101
(
2006
).
52.
L.
Berger
,
K.
Kleinheinz
,
A.
Attili
,
F.
Bisetti
,
H.
Pitsch
, and
M. E.
Mueller
, “
Numerically accurate computational techniques for optimal estimator analyses of multi-parameter models
,”
Combust. Theor. Modell.
22
,
480
504
(
2018
).
53.
S.
Yao
,
B.
Wang
,
A.
Kronenburg
, and
O. T.
Stein
, “
Conditional scalar dissipation rate modeling for turbulent spray flames using artificial neural networks
,”
Proc. Combust. Inst.
(unpublished) (
2020
).
54.
R. S.
Miller
and
J.
Bellan
, “
Direct numerical simulation of a confined three-dimensional gas mixing layer with one evaporating hydrocarbon-droplet-laden stream
,”
J. Fluid Mech.
384
,
293
338
(
1999
).
55.
P.
Schroll
,
A. P.
Wandel
,
R. S.
Cant
, and
E.
Mastorakos
, “
Direct numerical simulations of autoignition in turbulent two-phase flows
,”
Proc. Combust. Inst.
32
,
2275
2282
(
2009
).
56.
P.
Domingo
,
L.
Vervisch
, and
J.
Réveillon
, “
DNS analysis of partially premixed combustion in spray and gaseous turbulent flame-bases stabilized in hot air
,”
Combust. Flame
140
,
172
195
(
2005
).
57.
D. H.
Wacks
and
N.
Chakraborty
, “
Flame structure and propagation in turbulent flame-droplet interaction: A direct numerical simulation analysis
,”
Flow, Turbul. Combust.
96
,
1053
1081
(
2016
).
58.
Q.
Khan
,
S.
Baek
, and
H.
Ghassemi
, “
On the autoignition and combustion characteristics of kerosene droplets at elevated pressure and temperature
,”
Combust. Sci. Technol.
179
(
12
),
2437
2451
(
2007
).
59.
F.
Wang
,
R.
Liu
,
M.
Li
,
J.
Yao
, and
J.
Jin
, “
Kerosene evaporation rate in high temperature air stationary and convective environment
,”
Fuel
211
,
582
590
(
2018
).
60.
A.
Giusti
,
M. P.
Sitte
,
G.
Borghesi
, and
E.
Mastorakos
, “
Numerical investigation of kerosene single droplet ignition at high-altitude relight conditions
,”
Fuel
225
,
663
670
(
2018
).
61.
W. P.
Jones
and
R. P.
Lindstedt
, “
Global reaction schemes for hydrocarbon combustion
,”
Combust. Flame
73
,
233
249
(
1988
).
62.
B.
Wang
,
A.
Kronenburg
, and
O. T.
Stein
, “
Modelling sub-grid passive scalar statistics in moderately dense evaporating sprays
,”
Flow, Turbul. Combust.
103
,
519
535
(
2019
).
63.
S. B.
Pope
,
Turbulent Flows
(
Cambridge University Press
,
2000
).
64.
I.
Goodfellow
,
Y.
Bengio
, and
A.
Courville
,
Deep Learning
(
MIT Press
,
2016
).
65.
J. A.
Blasco
,
N.
Fueyo
,
C.
Dopazo
, and
J.
Ballester
, “
Modelling the temporal evolution of a reduced combustion chemical system with an artificial neural network
,”
Combust. Flame
113
,
38
52
(
1998
).
66.
R. W.
Stineman
, “
A consistently well-behaved method of interpolation
,”
Creative Comput.
6
(
7
),
54
57
(
1980
).
67.
S.
Ioffe
and
C.
Szegedy
, “
Batch normalization: Accelerating deep network training by reducing internal covariate shift
,” arXiv:1502.03167 (
2015
).
68.
F.
Pedregosa
,
G.
Varoquaux
,
A.
Gramfort
,
V.
Michel
,
B.
Thirion
,
O.
Grisel
,
M.
Blondel
,
P.
Prettenhofer
,
R.
Weiss
,
V.
Dubourg
,
J.
Vanderplas
,
A.
Passos
,
D.
Cournapeau
,
M.
Brucher
,
M.
Perrot
, and
E.
Duchesnay
, “
Scikit-learn: Machine learning in Python
,”
J. Mach. Learn. Res.
12
,
2825
2830
(
2011
).
69.
M.
Feurer
,
K.
Eggensperger
,
S.
Falkner
,
M.
Lindauer
, and
F.
Hutter
, “
Practical automated machine learning for the automl challenge 2018
,” in
International Workshop on Automatic Machine Learning at ICML
,
2018
.
70.
I.
Guyon
(
2019
)
et al., “
Analysis of the AutoML Challenge Series 2015–2018
,” in , The Springer Series on Challenges in Machine Learning, edited by
F.
Hutter
,
L.
Kotthoff
, and
J.
Vanschoren
(
Springer
,
Cham
,
2019
).
71.
C.
Jiménez
,
F.
Ducros
,
B.
Cuenot
, and
B.
Bédat
, “
Subgrid scale variance and dissipation of a scalar field in large eddy simulations
,”
Phys. Fluids
13
,
1748
1754
(
2001
).
72.
C.
Pera
,
J.
Réveillon
,
L.
Vervisch
, and
P.
Domingo
, “
Modeling subgrid scale mixture fraction variance in LES of evaporating spray
,”
Combust. Flame
146
,
635
648
(
2006
).
73.
J.
Floyd
and
A. M.
Kempf
, “
Computed tomography of chemiluminescence (CTC): High resolution and instantaneous 3D measurements of a matrix burner
,”
Proc. Combust. Inst.
33
,
751
758
(
2011
).
74.
A.
Géron
,
Hands-On Machine Learning with Scikit-Learn, Keras, and TensorFlow: Concepts, Tools, and Techniques to Build Intelligent Systems
(
O’Reilly Media
,
2019
).
75.
T.
Parr
,
K.
Turgutlu
,
C.
Csiszar
, and
J.
Howard
, “
Beware default random forest importances
” (
2018
), https://explained.ai/rf-importance; accessed June 2020.
76.
M.
Klein
,
N.
Chakraborty
, and
S.
Ketterl
, “
A comparison of strategies for direct numerical simulation of turbulence chemistry interaction in generic planar turbulent premixed flames
,”
Flow, Turbul. Combust.
99
,
955
971
(
2017
).
77.
D. H.
Wacks
,
N.
Chakraborty
, and
E.
Mastorakos
, “
Statistical analysis of turbulent flame-droplet interaction: A direct numerical simulation study
,”
Flow, Turbul. Combust.
96
,
573
607
(
2016
).
78.
F.
White
,
Viscous Fluid Flow
(
McGraw-Hill, Inc.
,
New York
,
1974
).
79.
G. M.
Faeth
, “
Current status of droplet and liquid combustion
,”
Prog. Energy Combust. Sci.
3
(
4
),
191
224
(
1977
), ISSN: 0360-1285.
You do not currently have access to this content.