DNS and LES of DNS and LES of Turbulent Combustion Turbulent Combustion

monkeyresultMechanics

Feb 22, 2014 (3 years and 3 months ago)

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1
“Computational
Fluid
Dynamics
In
Chemical
Reaction
Engineering
IV

June
19-24,
2005
Barga
, Italy
Luc Vervisch
INSA
de
Rouen,
IUF,
CORIA-CNRS
Pascale
Domingo,
Julien
Réveillon
Sandra
Payet
,
Cécile
Péra
&
Raphael
Hauguel
DNS
and
LES
of
DNS
and
LES
of
Turbulent
Combustion
Turbulent
Combustion
2

U
n
s
t
e
a
d
y

l
a
r
g
e

s
c
a
l
e
s

l
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a
d

t
o

a
n

i
m
p
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f
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c
t
m
i
x
i
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g

i
n

t
h
e

s
y
s
t
e
m
.

T
h
o
s
e

s
c
a
l
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s

a
r
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g
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o
m
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t
r
y

d
e
p
e
n
d
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t

a
n
d

f
e
a
t
u
r
e

a

l
o
n
g

l
i
f
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t
im
e
.

M
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c
r
o
-
m
i
x
i
n
g

m
e
c
h
a
n
i
s
m
s

b
r
i
n
g

r
e
a
c
t
a
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t
s

i
n
c
on
t
ac
t

w
i
th
in

t
h
in

r
ea
c
ti
o
n
z
o
ne
s
.
Combustion system
Combustion system
:
:
Large
Scales
Smaller
Scales
Turbulent flow
Turbulent flow
DNS
LES
????
? - ? - ? - ?
RANS
3
OUTLINE

DNS of turbulent combustion.


Overview of turbulent combustion modeling.

One example of SGS modeling in LES of
premixed turbulent combustion.

SGS modeling of partially premixed combustion.
4
Resolution
needed
for
full
simulation
Resolution
needed
for
full
simulation
:
:

Flow
:
50
Pflops
50
Tflops
50
Gflops
2015?
50
Pbytes
1500
2002
50
Tbytes
300
1993
50
Gbytes
70
Memory
Speed
Year
J. Jim
é
nez, Eng. Turbulence
Modelling and Experiments-5, 2002
Mizobuchi et al, Proc. Combust. Inst. 2002


Flame (CH4/AIR)
:
5
So
far,
three
types
of
So
far,
three
types
of


full
solutions
full
solutions



(DNS)

(DNS)
:
:
Chemistry:


Single-step

Reduced

Tabulated

Detailed
Transport:

Fixed Lewis and Schmidt

Variable Lewis & Schmidt

Complex

DNS of synthetic model problem (freely decaying turbulence).
Synthetic problem
Cambridge
Laboratory flame at lower Re
Sandia,
Livermore

DNS of laboratory flame, but at much lower Re.
INSA
Real jet-flame

DNS of laboratory flame.

JAXA
6
Premixed
Turbulent
V-Flame
Premixed
Turbulent
V-Flame
HOT
WIRE
RANS
VIEW
DNS
Boukhalfa
& Renou
,
INSA
de
Rouen
7
OH
Complex chemistry FPI-FGM
:
Gicquel
et
al
Proc.
Combust.
Inst.
Vol.
28,
1901-1908,
2000.
Oijen
et
al

Combust.
Flame,
127(3):2124-2134,
2001.
8
RANS VIEW
RANS VIEW
9
Overview of turbulent
Overview of turbulent
combustion modeling tools
combustion modeling tools
10
Flame
Flame
surface
surface
density
density
G-
G-
Eq
Eq
or c-
or c-
Eq
Eq
Flamelet modeling
Flamelet modeling
CMC
PDF transport
11
Control parameter of molecular mixing?
Control parameter of molecular mixing?
Fuel
Oxi
Oxi
12
Micromixing
Micromixing
Combustion
Tools
Veynante
&
Vervisch,
Prog
In
Energ Sci
, 28:193-266 2002
Conditional scalar
dissipation rate
PDF
Surface or G-
field
13


Academic
Academic



combustion
regimes

combustion
regimes
Fuel
+
Oxidizer
ΦΖ
ο


Products
Diffusion
Fuel
Oxi
Oxi
Z = 1
Z = 0
Z = 0
Z
s
Pr
émélange
14
Premixed flame LES
Premixed flame LES
filtering
filtering
Filtering a
stoichiometric
premixed Propane/Air Flame
SGS fluctuation
15
SGS
SGS
Probability Density Function in premixed flames:
Probability Density Function in premixed flames:


The
thin
flame
front
has
a
characteristic
scale
within the
subgrid.


The
thin
flame
is
seen
at
the
grid
scale

.
1.
Thickening
by
the
filter
of
the
thin
flame
front
over
the
coarse
LES
grid.
2.
Wrinkling
of
the
flame
within
the

subgrid
that
results
from
interaction
with
subgrid
vortices.
EFFECTS
16
Flame
surface
density
contains
information
Flame
surface
density
contains
information
on
the
flame
characteristic
length:
on
the
flame
characteristic
length:
DNS
17
Laminar flame
Laminar flame
Filtered gradient contains two points information
Filtered gradient contains two points information
18
Get the PDF from the Flame Surface Density inside the flame:
Get the PDF from the Flame Surface Density inside the flame:
19
Describing
SGS
variance
of
progress
variable:
Energy that is not resolved by the coarse LES grid.


Try
to
get
it
from
resolved
scales:
-
Scale
similarity
hypothesis.
-
Equilibrium
hypothesis.


Solve
a
balance
equation
to
get
SGS
variance:
-
Which
balance
equation
is
the
best?
-
Close
unknown
terms.
20
Scale similarity assumption:
Filtered DNS
21
Equation for SGS variance:
Production - Dissipation and Source
Dissipation:
22
Equilibrium
hypothesis:
Filtered DNS
Depends on geometry and chemistry

23
Unmixedness
:
S
0
1
Chose
the
appropriate
variable
to
be
transported
Chose
the
appropriate
variable
to
be
transported
(the one that minimizes LES numerical problems
(the one that minimizes LES numerical problems


)
)


Solve for the departure from maximum variance:
24

The modeled balance equations to be
The modeled balance equations to be
solved for presuming the PDF then
solved for presuming the PDF then
reads:
reads:
Scalar dissipation rate
Scalar dissipation rate
Chemical source
Chemical source
25
LES
CHEMICAL
TABLES
LES
CHEMICAL
TABLES
Averaging
FGM
or
FPI
Averaging
FGM
or
FPI
FPI
(Flame
Prolongation
of
ILDM):
Gicquel
et
al
Proc.
Combust
.
Inst
.Vol.
28,
1901-1908,
2000.

FGM
(Flame
Generated
Manifod
):
Oijen
et
al

Combust
.
Flame
,
127(3):2124-2134,
2001.
26


Fully Compressible Flow.
Fully Compressible Flow.


4th
4th
ordre
ordre
in space, 2nd in time.
in space, 2nd in time.
Skew
symmetric
like,
Skew
symmetric
like,
Ducros
Ducros
et al, J.
et al, J.
Comput
Comput
. Phys., 161: 114-139, 2000.
. Phys., 161: 114-139, 2000.


Dynamic
Dynamic
Lagrangian
Lagrangian
Modeling.
Modeling.
Meneveau
Meneveau
et al, JFM, 353-386, 1996.
et al, JFM, 353-386, 1996.


Structure Function.
Structure Function.
M.
M.
Lesieur
Lesieur
Team.
Team.
SGE:
27
Test premixed SGS modeling on ORACLES
Test premixed SGS modeling on ORACLES
(Nguyen and
(Nguyen and
Bruel
Bruel
, AIAA-2003-0958.)
, AIAA-2003-0958.)
28
Time averaged
Time averaged
streamwise
streamwise
velocity frozen flow mixing:
velocity frozen flow mixing:
29
Time averaged
Time averaged
streamwise
streamwise
velocity:
velocity:
Progress variable:
Progress variable:
30
Time averaged
Time averaged
spanwise
spanwise
velocity:
velocity:
31
Time averaged
Time averaged
spanwise
spanwise
velocity:
velocity:
32
Time averaged RMS velocity:
Time averaged RMS velocity:
33
OUTLINE


DNS
of
turbulent
combustion.

Overview
of
turbulent
combustion
modeling.


One
example
of
SGS
modeling
for
LES
of
premixed
turbulent
combustion.


SGS
modeling
of
partially
premixed
combustion.
34
Nox
emission control
Industrial
combustion
35
Zone 1:

Premixed
properties


Thin
reaction
zones


Interface
fresh/burnt

Propagation

Stabilization
Zone 2:
Diffusion
properties

Mixing controlled

Pollution

Flame length
From burner
Nonpremixed
Nonpremixed
turbulent flame base:
turbulent flame base:
Muniz &
Mungal
, Combust. Flame 111(1/2), 1997
36
Diffusion flame
Equilibrium
Premixed
Combustion
Flux in Z
Diffusion is faster
Chemistry
is
faster
Premixed/Diffusion combustion
Premixed/Diffusion combustion
Fiorina
et
al.
Combust.
Flame,
140(3),
147-160,
(2005)
Methane-air
37
Premixed
Fuel + Oxidizer
Takeno
Takeno


s flame index to determine combustion regime
s flame index to determine combustion regime
:
Products
Diffusion
Fuel
Oxidizer
38
Sixth order PADE, Third order time stepping, NSCBC Boundary conditions
Mixture fraction
Progress
variable
Conditional
flame index
ξ
p

1
2
1

n

F

n

O




Premixed
Diffusion
St
=
0.4
Hot air 900K
DNS
of
lifted
flames
DNS
of
lifted
flames
:
:
39
Gaseous
Gaseous
Spray
Spray
Marley
et
al.
FTaC
72(1),
29-47,
2004
DNS
of
weakly
turbulent
flame
bases
DNS
of
weakly
turbulent
flame
bases
:
:

40
Turbulent flame base structure (gaseous case)
Turbulent flame base structure (gaseous case)
:
:
Ghosal
&
Vervisch,
JFM,
415,
227-260
(2000)
Li
&
Williams,
Combust.
Flame,
118(3):399-414,
(1999)
Rich partially premixed
Mixing
Fuel
Oxidizer
Z
s
41
Amplitude of the burning rate in premixed mode
Amplitude of the burning rate in premixed mode
:
:
= 1 Premixed
=
0
Diffusion
42
Fraction of premixed burning
Fraction of premixed burning
:
:
Gaseous
Gaseous
Spray
Spray
x
y
Gaseous
Gaseous
Spray
Spray
43
Diffusion
Diffusion
flamelet
flamelet
, but only for the
, but only for the


diffusion-part
diffusion-part


:
:
Gaseous
Gaseous
Spray
Spray
44
Flame
decomposition
Flame
decomposition
:
Modeled
decomposition
Modeled
decomposition
:
Modeled
coefficients
Modeled
coefficients
:
45
Modeled
decomposition
Modeled
decomposition
:
Gaseous
Gaseous
Spray
Spray

Domingo et al,
“DNS
analysis
of
partially
premixed
combustion
in
spray
and
gaseous
turbulent-flame
bases
stabilized
in
hot
air
”,
Combust.
Flame,
103(3):
172-195,
2005.

Reveillon
& Vervisch,
“Analysis
of
weakly
turbulent
diluted-spray
flames
and
spray
combustion
regimes

, JFM, 537:317-
347, 2005.