Post on 09-Feb-2019
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Valeri I. Golovitchev
POSSIBLE ”ROAD” MAP OF SOLVING NEW SPRAY COMBUSTION PROBLEMS IN COMPRESSION IGNITED ENGINE MODELING
Chalmers University of TechnologyGothenburg, Sweden
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Valeri I. Golovitchev
POSSIBLE ”ROAD” MAP OF SOLVING NEW SPRAY COMBUSTION PROBLEMS IN COMPRESSION IGNITED ENGINE MODELING
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
With contribution of:Mr. J. GustavssonDr. N. Nordin
Dr. Y. Murata (Waseda University, Japan)
Dr. L. Montorsi (University of Modena and Reggio Emilia)
Miss A. Häggström (SCANIA AB)
Miss M. Bergman
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Spray atomization models
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
‘breakup’
parcel
droplet rp0
parent
child
new parent−
= −p p c
b
dr r rdt t Λ
= Λ
0 KH
c RT
Br
2
τ
Λ Ω= Ω
1 p0
KH KHb
RT
3.726 B r
tC
Λ Ω
Λ ΩKH KH
RT RT
,
,
ΛKHΛ0 KH2B
ΛRT
ΛRT
ρ=ρ
lb b 0
g
L C d
Hybrid Kelvin-Helmholtz/ Rayleigh-Taylor droplet breakup model
*
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Droplet drag model
ρ= ρ = ⋅
uuru
ur
ur
rup d
2gp
l d f
Udv Um V A
dt 2 Ua C
+
23d
d
24 11 Re
Re 6=d,sphereC
0.424
≤dRe 1000
>dRe 1000
= +d,sphered C (1 2.C 632 y)
Taylor Analogy Model
ρ σ µ= − −
ρ ρ ρ&& &
2g l
2 3 2l l l
U2 8 5y y y
3 r r r
Droplet’s equation of motion
Modified Stokes’ low
= ⋅ + ⋅r r rr
t pg jg a j
nozzle
uuuuuurpv
uuurg
uurj
uuuuuurpx
the direction of travel
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Improved 3-D spray model
850.0 K, 4.03 MPa, 16.0 kg/m3
Dis
tanc
e fr
om th
e no
zzle
m
m
0
60
20
40
80
Pen
etra
tion
mm
Time ms
Injection duration
Am
ount
of e
vapo
rate
d fu
el m
g
Time ms
Injection quantity
( Wall )
Droplet diameter mm
Fuel vapor g/cm3
0.0 0.13 0.26
0.0 0.023 0.0045
0
20
40
60
80
0 0.3 0.6 0.9 1.2 1.5
0
4
8
12
16
0 0.5 1 1.5 2 2.5
KH-RT model
KH model
KH-RT model
KH model
KH model
Liquid Vapor
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Validation of 3-D spray modelD
sita
nce
from
the
nozz
le
mm
0
60
20
40
80
Pen
etra
tion
mm
Time ms
KH-RT modelExp.
850.0 K, 4.03 MPa, 16.0 kg/m3
KH-RT model
Exp.
( Wall )Droplet diameter mm
Fuel vapor g/cm3
0.0 0.13 0.26
0.0 0.023 0.0045
0
20
40
60
80
0 0.2 0.4 0.6 0.8 1 1.2
KH-RT model can predict the measured maximum penetration of the liquid phase under high pressure and temperature conditions
KH-RT model
Exp.
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Multi-Stage Fuel Injection - II
(Pilot and Post Injection in Spray Combustion Modeling)
Series of smaller injections must be optimized to achieve design goals
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Fuel compositions studied
Fuel A-D• Different three-component mixtures• Large spread in volatility
Fuel E• Blend of n-heptane and toluene• Used as fuel vapour representation in
the Diesel surrogate model (Chalmers)• Species with similar volatility
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Fuel mixtures in the study
0.30----0.70Fuel E (mole)
-0.600.300.10--Fuel D (mass)
-0.330.330.33--Fuel C (mass)
-0.100.300.60--Fuel B (mass)
-0.33--0.330.33Fuel A (mass)
tolueneC7H8
n-hexadecaneC16H34
n-dodecaneC12H26
iso-octaneC8H18
n-decaneC10H22
n-heptaneC7H16
• Myong, K., Suzuki, H., Senda, J., Fujimoto, H., Spray Structure of Multi-Component Fuels on Evaporating Transient Diesel Sprays, Thiesel Conference, Valencia (2004).
• Myong, K., Arai, M., Suzuki, H., Senda, J., Fujimoto, H., Vaporization Characteristics and Liquid-Phase Penetration for Multi-Component Fuels, SAE 2004-01-0529 (2004).
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Large volatility differences (A)
0
1
0 0,0001 0,0002t (s)
d2 /d02 (
-)
Cold-start
Idle
• No notable sequential evaporation.
• Volatility differences are reduced at high temperatures and pressures.
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Large volatility differences (A)
Idle
0
1
0 0,0001t (s)
Mas
s fr
actio
ns (
-)
n-heptanen-decanen-hexadecane But…
Mass fractions in dropletchanges during evaporation.
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Large volatility differences (B-D)Cold-start
0
1
0 0,0001 0,0002t (s)
d2 /d0
2 (-)
Fuel BFuel CFuel D
Idle
0
1
0 0,0001t (s)
d2 /d02 (
-)
Fuel BFuel CFuel D
• No notable sequential evaporation.• Evaporation rates are similar.• Heat-up times differ.
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Large volatility differences (B-D)
Idle, Fuel C
0
1
0 0,0001t (s)
Mas
s fr
actio
ns
iso-octanen-dodecanen-hexadecane
• Mass fractions in droplet changes during evaporation process.
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Similar volatility (E)
Idle
0
1
0 0,00005t (s)
d2 /d02 (
-)
Pure n-heptanePure tolueneFuel E
Evaporation rates ofpure species andthe mixture are similar.
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Idle
0
1
0 0,00005t (s)
d2 /d02 (
-)
Pure n-heptanePure tolueneFuel E
Evaporation rates ofpure species andthe mixture are similar.
Similar volatility (E)
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Droplet Spray Collision Model: New Approach
Binary collision schematics in relative motion
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
30 deg. 60 deg. 90 deg.
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Regime diagram for turbulent combustion
* Borghi(1995), Peters(1999), Poinsot(1991)
Laminar plane flame fronts
Well-stirred combustion
Da<<1
Da=1
Wrinkled flame fronts
Corrugated flamelets
Distributed combustion
Peters criterion (Ka=100)
Klimov -Williams criterion (Ka=1)
Thin reaction zone
10-1 100 101 102 103 104
10-1
100
101
102
103
104
lI/δL
u rms/S
L
Ka>1
Torn flame fronts
Island formation
Ka~1
Ka<1
Da>>1
Ret =1
Laminar plane flame fronts
Well-stirred combustion
Da<<1
Da=1
Wrinkled flame fronts
Corrugated flamelets
Distributed combustion
Peters criterion (Ka=100)
Klimov -Williams criterion (Ka=1)
Thin reaction zone
10-1 100 101 102 103 104
10-1
100
101
102
103
104
lI/δL
u rms/S
L
Ka>1
Torn flame fronts
Island formation
Ka~1
Ka<1
Da>>1
Ret =1
Ret=urmslI/νTurbulent Reynolds number
Damkohler number
Karlovitz number
Da=τI/τchem
Ka=τchem/τη
dominated by chemical kinetics
dominated by turbulent mixing
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Reactive volume = computational cell
Averaged concentrations at the beginning of the integration step: [X] i
0 Averaged concentrations at the end of the integration step: [X]i1
Reaction zone : mixed
Reaction zone:
(treated as a PSR**)
[X]i
Time-averaged concentrations
*PaSR: Partially Stirred Reactor **PSR: Perfectly Stirred Reactor
mixed and reacting
Conceptual schematic diagram of the PaSR* model
[Xs]0
Spe
cies
con
cent
ratio
n ?
?
t tctmixTime
[Xs]1
[Xs]
− −= = = − = −
τ τ τ τ
1 1 0 11s s s s s s s
r sc mix c
d[X ] [X ] [X ] [X ] [X ] [X ] [X ]f ([X ] ) ,
dt
tmix: the micro-mixing timetc: the chemical reaction timet : the calculation time step
−
=
∂ −τ = τ = − ≈ ε ∂ + τ
e1
s s
01 r s r
mix mix c 0s s r[ X ] [ X ]
f ([X ])k fC ,
[X ] [X ] term
by V.I.Golovitchev
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Engine geometry andoperating condition
Chemical kinetic calculation (PaSR model)
Output files
Read thermodynamic properties
Fluid dynamic calculation(RNG k-emodel)
KIVA-3V
Spray breakup calculation(KH-RT model)
Elementaryreactions (chem.inp)
CHEMKIN libraries for reading binary file
Thermodynamic properties(therm.dat)
CHEMKIN Interpreter
Binary file for thermal properties
and rate parameters
CHEMKIN-II
Integration PaSR Model into KIVA3 Code
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
0.001
0.01
0.1
1
10
100
1000
10000
0.7 0.9 1.1 1.3 1.5 1.7
0.001
0.01
0.1
1
10
100
1000
10000
0.7 0.9 1.1 1.3 1.5 1.7
LLNL
COSMO Oil
n-heptaneoxidation
mechanism( f =1.0) Ig
nitio
n de
lay
ms
http://www-cms.llnl.gov/combustion/combustion2.html
Combustion and Flame
133 (2003) 467-481
Igni
tion
dela
y m
s
0.01
0.1
1
10
100
1000
10000
0.7 0.9 1.1 1.3 1.5 1.7
0.001
0.01
0.1
1
10
100
1000
10000
0.7 0.9 1.1 1.3 1.5 1.7
29 species , 52 reactions
http://www.erc.wisc.edu/modeling/modeling_index.htm
Chalmers Univ.
1000/T 1/K
62 species , 255 reactionshttp://www.tfd.chalmers.se/~valeri/MECH.html
V.I.Golovichev
1000/T 1/K
561 species, 2539 reactions160 species, 1540 reactions
32 species , 55 reactions
10 MPa
4.2 MPa
1.35 MPa
0.32 MPa
0.1 MPa
S.Tanaka
ERC
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Process of Soot and NO formation modelSoot formation mecahnism
NO formation mecahnism
A2R5 ? x C(S)Graphitization5
Detailed chemistryAcetylene oxidation4
Detailed chemistryAcetylene formation2
Detailed chemistryPrecursor radical oxidation
3
6
1
No.
C(S)+O2 ? O+COC(S)+CH3 ? H+C2H2
C(S)+OH ? CO+HSoot oxidation
Detailed chemistry up to A2R5
Precursor radical formation
Chemical reactionProcess+C2H2
+C2H2
+C2H2
+C2H2
+C2H2
-H2
-H2
-H
+H
-H
+H
(A2R5)
Phenyl Naphthyl
Acenaphthylene
HACA* mechanism by Frenklach et al.
N2+O ? NO+N N+O2 ? NO+ON+OH ? NO+H
Extended Zel’dovichmechanism
Mechanism Chemical reaction* : H-abstraction, C2H2 addition
+
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Soot NO
1000 1400 1800 2200 2600 3000 1000 1400 1800 2200 2600 3000
Temperature K Temperature K
Equ
ival
ence
ratio
F
109876543210
109876543210
Smokeless Rich Combustion by Reducing Temperature Akihama et al.
Desirable Path Kamimoto et al.
Equ
ival
ence
ratio
FMK combustion
HCCI Fuel : n-heptane, P : 6 MPa, reaction time : 1.0 ms
zero-dimensional calculation by using CHEMKIN-IICharacteristics of reaction mechanism on F -T map
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
1000 1400 1800 2200 2600 3000
1098765432101000 1400 1800 2200 2600 3000
109876543210
109876543210
1000 1400 1800 2200 2600 3000
1098765432101000 1400 1800 2200 2600 3000
109876543210
109876543210
Pressure Dependence of Soot-F -T map
1000 1400 1800 2200 2600 3000
1098765432101000 1400 1800 2200 2600 3000
109876543210
109876543210
Temperature K Temperature K Temperature K
1 MPa 3 MPa 6 MPa
Equ
ival
ence
ratio
F
Fuel : n-heptane, reaction time : 1.0 ms, EGR 0%
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Fuel : Diesel surrogate (70% n-heptane, 30% toluene)
Analysis of Emission Formations in Diesel Engines
Equivalence ratio – Temperature Soot-Nox maps
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Fuel : Diesel surrogate (70% n-heptane, 30% toluene)
Analysis of Emission Formations in Diesel Engines
Equivalence ratio – Temperature CO maps
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Engine specifications, the experimental and computational conditions
-6-5-10Start of injectiondeg.ATDC
39(1/4 Load)
75
36(1/4
Load)
100Injection pressure MPa
Common-rail injection systemInjection equipment
Natural AspirationAir intake system
16.0Compression ratio
Direct injection, single cylinder, water-cooled, 4-stroke-cycle
Type of engine
1000Engine speed rpm
2.147Displacement L
83(3/4
Load)Amount of fuel mg
135×150Bore×Stroke mm
F 0.26 mm×6 (150 deg.)Common-rail Injector
-120~ 120(IVC~ EVO)
Crank angle deg.ATDC
Pentium4 3GHz×1,1GB Memory
CPU
26×30×29(?=60 deg.)
Mesh size r×?×Z
(@-180 deg.ATDC)
A B C D
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
PaSR
model
validation
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
0
1
2
3
4
5
6
7
-40 -30 -20 -10 0 10 20 30 40 50 600
50
100
150
200
250
300
350
400
450
500
In-cylinder mass histories of
Crank angle deg.ATDC
Pre
ssur
e M
Pa
R.H
.R
J/de
g.
D
?inj= -6 deg.ATDC
3/4 Load
MeasuredCalculated
characteristic chemical species
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
In-cylinder distribution of temperature and fuel in the liquid phase
Droplet diameter mm
Temperature K
0.0 0.13 0.26
450 1375 2300
5 deg.ATDC 7 deg. ATDC 9 deg. ATDC 11 deg. ATDC-3 deg.ATDC -1 deg. ATDC 1 deg. ATDC 3 deg. ATDC
5 deg.ATDC 7 deg. ATDC 9 deg. ATDC 11 deg. ATDC-3 deg.ATDC -1 deg. ATDC 1 deg. ATDC 3 deg. ATDC
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
0
0.5
1
1.5
2
2.5
3
3.5
4
-20 0 20 40 60 80 100 120
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
-20 0 20 40 60 80 100 120
0
0.01
0.02
0.03
0.04
0.05
1 20
1 2
Cal
cula
ted
soot
mas
s m
gN
O m
ass
mg
soot
mas
s m
g
1/4 Load3/4 Load
1/4 Load 3/4 Load
MeasuredCalculated
1/4 Load3/4 LoadMeasured
Soot NO
Crank angle deg.ATDC
CD
CD
D
(PM)
15 deg.
30 deg.
45 deg.
60 deg.
(ATDC)
Formation histories of soot and NO
(1000 ppm) (3000 ppm)
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Modeling of Isotta Fraschini IF-1300 Marine DI Diesel engine
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Modeling of Volvo NED5 DI Diesel engine
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
Modeling of Volvo DI NED5 and D12 Diesel engines
Volvo Car NED5 Volvo Powertrain D12
HCCI Mode MK Combustion
Chalmers University of Technology
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005
New problem: Free Piston, FP, Engine Modeling
Schematic of the FP combustion chamber FP operation modeling
HTCES – High Tech Cars and Engines – Modena, Italy – May, 26-27 2005