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Lawrence Livermore National Laboratory
Multidimensional simulation and chemical kinetics development for high efficiency clean combustion engines
Dan Flowers, Salvador Aceves, William J. Pitz
DOE DEER MeetingDearborn Michigan, Aug 5, 2009
This presentation does not contain any proprietary or confidential informationThis work performed under the auspices of the U.S. Department of
Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344
2LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National Laboratory
Our team develops chemical kinetic mechanisms and applies them to simulating engine combustion processes
LLNL Team•
Salvador Aceves
•
M. Lee Davisson•
Dan Flowers
•
Mark Havstad•
Nick Killingsworth
•
Matt McNenly•
Marco Mehl
•
Tom Piggott•
William J. Pitz
•
J. Ray Smith•
Russell Whitesides
•
Charles K. Westbrook
Partners•
DOE working groups•
Sandia Livermore•
Oak Ridge•
Los Alamos•
International•
UC Berkeley•
University of Wisconsin•
University of Michigan•
Chalmers University•
FACE working group•
National Univ. of Ireland•
RPI•
Princeton University•
Univ. of Tokyo
3LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National Laboratory
We apply simulations methodologies to gain insight into advanced combustion regimes
Prediction of partially stratified combustion with kiva3v-multizone Improved surrogate chemical
kinetic model for gasoline
Simulating SI-HCCI transition with ORNL
Prediction of PCCI combustion with an artificial neural network-based chemical kinetic model
Improved kinetic solver numerics
4LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National Laboratory
Improving models for diesel engines
•
Completed development of high and low temperature model for heptamethyl nonane, important component and primary reference fuel for diesel
Improving models for gasoline-
fueled engines:
•
Completed validation of component models for n-heptane, iso-octane and toluene, important components for gasoline fuels
CH3
Developed new surrogate models for gasoline fuels
We continue to expand and improve chemical kinetic mechanisms for diesel and gasoline components
5LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National Laboratory
One of the two primary reference fuels for diesel ignition properties (cetane number)
•
n-hexadecane
•
2,2,4,4,6,8,8 heptamethylnonane
High and low temperature portion of the mechanism complete
•
First-ever complete set of high and low temperature kinetic mechanisms for heptamethylnonane
Recommended surrogate for diesel fuel (Farrell et al., SAE 2007):
We have developed a model for heptamethylnonane, a primary reference fuel for diesel
6LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National Laboratory
n-alkanebranched alkanecycloalkanesaromaticsothers
butylcyclohexanedecalin
hepta-methyl-nonane
n-decyl-benzenealpha-methyl-naphthalene
n-dodecanen-tridecanen-tetradecanen-pentadecanen-hexadecane
tetralin
New diesel component model this year
New components last year
New component next year
Diesel Fuel Surrogate palette:
7LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National LaboratoryLLNL-PRES-123456
C -
C -
C -
C -
C -
C -
C -
C -
CC C C C
C C C
C -
C -
C -
C -
C
C C
C
Site-specific reaction rates for HMNbased largely on iso-octane
Heptamethylnonane (HMN) has a lot of structural similarities to iso-octane
HMN
iso-octane
8LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National Laboratory
Heptamethyl nonane (HMN) detailed chemical kinetic mechanism contains 1114 species 4468 reactions
Iso-octane and HMN are surrogate components useful for Fischer-Tropsch fuels that can be bio-derived
Mechanism includes low and high temperature reactions => can examine low temperature combustion strategies in engines
Recent experiments now available on HMN for mechanism validation
2,2,4,4,6,8,8 heptamethylnonane
9LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National Laboratory
Recent experimental results show excellent agreement with modeling for HMN
Experimental data shock tube data on iso-cetane (or HMN) from
Oehlschlaeger et al, Rensselaer Polytechnic Institute, 2009
10LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National LaboratoryLLNL-PRES-123456
Improved component models
Recent improvements to fuel surrogate models: Gasoline
11LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National Laboratory
Improving numerics: Processing the Jacobian is the most computationally expensive part of CHEMKIN-Multizone
94% of the total computational cost solving kinetic ODEs is spent generating the Jacobian and solving the associated linear system.
Computational breakdown of the CHEMKIN - Multizone model
0
10
20
30
40
50
60
Generating Jacobian Solving JacobianSystem
Other
Original Method
Perc
enta
ge o
f orig
inal
cost
32M calls to the CHEMKIN species production rate
4400 Gaussian eliminations for 1300 x 1300 system
12LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National Laboratory
We apply LLNL’s ODE integrator with an iterative matrix solver (DLSODPK)
Use LLNL’s iterative solver DLSODPK along with a preconditioner matrix PP-1Ax = P-1b
Here P is the Jacobian of a simplified CHEMKIN-multizone model that yields a block diagonal matrix (neglecting interaction between zones)
Internal zone variables
Zero
13LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National Laboratory
The new DLSODPK scheme accelerates computations enabling detailed multizone kinetics on desktop PCs
Computational breakdown of the CHEMKIN - Multizone model
0
10
20
30
40
50
60
Generating Jacobian Solving JacobianSystem
Other
Original MethodDLSODPK
Perc
enta
ge o
f orig
inal
cost
17x fewer calls to CHEMKIN species production rate Total Gaussian elimination cost is
+400x smaller
60x speedup for 20 zones; 6 minutes (6 hours) with 63 species250x speedup for 40 zones; 24 minutes (100 hours) 63 species
14LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National Laboratory
We are analyzing ORNL results for stability and emissions during SI-HCCI transition due to increased residual gas fraction
IgnitionHeattransfer to walls
Flame propagation
15LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National Laboratory
1-dimensional chemical kinetic model matches pressure traces well for motored, SI and HCCI cases
Spark-ignited
HCCI (RGF=75%)
16LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National Laboratory
ORNL Test data for SI to HCCI transition: heat release patterns vary with residual gas fraction
Increasing RGF
Increasing RGF
Spark-ignited (RGF~10%)
HCCI (RGF~60%)
17LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National Laboratory
LLNL
Simulation results for SI to HCCI transition: heat release patterns vary with residual gas fraction
Increasing RGF
Increasing RGF
Spark-ignited (RGF~10%)
HCCI (RGF~60%)
18LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National LaboratoryLLNL-PRES-123456
We are analyzing three consecutive cycles of the Sandia automotive PCCI engine (Steeper)
19LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National LaboratoryLLNL-PRES-123456
The Sandia engine runs in PCCI mode with dual injection: one injection during NVO and a main injection
20LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National LaboratoryLLNL-PRES-123456
KIVA3V-MZ-MPI shows promise for accurately predicting direct injected PCCI
21LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National Laboratory
Summary: we are enhancing our analysis capabilities and improving computational performance
Partially stratified combustionGasoline surrogate
HCCI-SI transition modeling60x-250x Improved numerics
22LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National Laboratory
Summary: we are expanding the range of mechanisms available for representative fuel components
Diesel Fuel Palette Gasoline Fuel Palette
24LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National LaboratoryLLNL-PRES-123456
Improved component models
Recent improvements to fuel surrogate models: Gasoline
25LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National LaboratoryLLNL-PRES-123456
n-Heptane and iso-octane behave well over a wide pressure and temperature range
0.8 0.9 1 1.1 1.2 1.3 1.4 1.5
15 atm 34 atm
45 atm
1000K/T
Iso-octane0.1
1
10
100
Igni
tion
Del
ay T
imes
[ms]
0.1
1
10
100
50 atm
41 atm
20 atm
6.5 atm10 atm
13 atm
3-4.5 atm
30 atm
n-heptane
0.8 0.9 1 1.1 1.2 1.3 1.4 1.5
1000K/T
Igni
tion
Del
ay T
imes
[ms]
Shock tube and rapid compression machine validation of n-heptane & iso-octane mechanisms:n-heptane:P = 3 -
50 atmT = 650K -
1200K= 1
Minetti R., M. Carlier, M. Ribaucour, E. Therssen, L. R. Sochet (1995); H.K.Ciezki, G. Adomeit (1993); Gauthier B.M., D.F. Davidson, R.K. Hanson (2004); Mittal G. and C. J. Sung,(2007);
Minetti R., M. Carlier, M. Ribaucour, E. Therssen, L.R. Sochet (1996); K. Fieweger, R. Blumenthal, G. Adomeit (1997).
Significant improvements over the whole range of pressures
iso-octane:P = 15 -
45 atmT = 650K -
1150K= 1
26LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National LaboratoryLLNL-PRES-123456
1E-6
1E-5
1E-4
1E-3
1E-2
1100 1150 1200 1250 1300 1350 1400
T[K]
Mol
e Fr
actio
n
TOLUENECH2OCH4BENZALDEHYDE
After much development work, toluene mechanism behaves quite well
Good agreement with experimental measurements
The model explains the differences between the ignition delay times obtained in shock tube and rapid
compression machine experiments
Species profiles measured in a jet stirred reactor are correctly reproduced as wellP = 1 atmΤ
= 0.1s
Dagaut, P., G. Pengloan, Ristori, A. (2002)
Mittal G. and Sung, C.J. (2007)
Vanderover, J. and Oehlschlaeger, M. A. (2008)
1
Igni
tion
Del
ay T
imes
[ms]
toluene
0.7 0.8 0.9 1 1.1
1000K/T
Shock Tube 12 atm
Shock Tube 55 atm
Rapid Compression Machine 44 atm
10
1000
100
0.1
0.01
stoichiometric
27LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National LaboratoryLLNL-PRES-123456
Examined binary and surrogate mixtures relevant to gasoline fuels
n-paraffins
arom atics
olefins
naphthenes
Oxygenates
Iso -paraffins
CH3CH3
CH 3CH 3
EtOH , MTBE, ETBE
Gasoline fuel surrogate palette
28LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National LaboratoryLLNL-PRES-123456
1
10
100
1000
0.9 1 1.1 1.2 1.3 1.4 1.5 1.6
1000K/T
Igni
tion
Del
ay T
imes
[ms]
Toluene 15 atm
Mixture 3.9-4.9 atm
N-heptane 3.3-4.6 atm
Mechanism simulates well n-heptane/toluene mixtures in a rapid compression machine
•
50% 50%
Toluene delays the low temperature heat release and high temperature ignition
Allylic site on toluene depresses reactivity of mixture by formation of unreactive benzyl radicals
R• RH
Experiments: Vanhove, G., Minetti, R., Petit, G. (2006)
29LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National LaboratoryLLNL-PRES-123456
1
10
100
1000
0.9 1 1.1 1.2 1.3 1.4 1.5 1.6
1000K/T
Igni
tion
Del
ay T
imes
[ms]
Toluene 15 atm
Iso-octane 12.6-16.1 atm
Mixture 12-14.6 atm
65% 35%
Vanhove, G., Minetti, R., Petit, G. (2006)
Iso-octane/toluene mixtures well simulated
Interactions similar to those observed for n-heptane
Toluene addition lowers low temperature heat release and delays high temperature ignition
500
700
900
1100
1300
1500
0 50 100 150
Iso‐Octane
Mixture
T [K
]
Time [ms]
30LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National LaboratoryLLNL-PRES-123456
1
10
100
1000
0.9 1 1.1 1.2 1.3 1.4 1.5 1.6
1000K/T
Igni
tion
Del
ay T
imes
[ms]
1-hexene 8.5-10.9 atm
Iso-octane 12.6-16.1 atm
Mixture 11.4-14 atm
Iso-octane/1-hexene mixtures well simulated
Allylic site on 1-hexene depresses reactivity of mixture
Some low temperature reactivity from 1-hexene
82% 18% •R• RH
• Ketohydroperoxides + OH
Radical Scavenging from the double bond
•OHHO •
Experimental data: Vanhove, G., Minetti, R., Petit, G. (2006)
31LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National Laboratory
1
10
100
1000
0.9 1 1.1 1.2 1.3 1.4 1.5 1.6
1000K/T
Igni
tion
Del
ay T
imes
[ms]
Toluene 15 atm
1-hexene 8.5-10.9 atm
Mixture 11.4-13.9 atm
Experimental data: Vanhove, G., Minetti, R., Petit, G. (2006)
Reasonable agreement for toluene/1-hexene mixtures
30% 70%
•
Formation of allylic radicals suppresses reactivity
•
Some low temperature reactivity from 1-hexene
• Ketohydroperoxides + OH
LLNL-PRES-411416
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Lawrence Livermore National LaboratoryLLNL-PRES-123456
1E-7M
ole
frac
tions
700 800 900 1000 1200
T [K]
1E-6
1E-5
1E-4
1E-3
1100
CH2O C4H6 C6H6
CH2O C4H6 C6H6
1
10
100
1000
0.9 1 1.1 1.2 1.3 1.4 1.5 1.6
1000K/T
Igni
tion
Del
ay T
imes
[ms]
Surrogate 11.8-14.8 atm
Gasoline surrogate well simulated
47% 35% 18% 50% 35% 15%
Experiments: Vanhove, G., Minetti, R., Petit, G. (2006)
Rapid compression machine validation Jet stirred reactor validation: 10 atm, τ
= 0.5 sExperiments: M. Yahyaoui, N. Djebaïli-Chaumeix, P. Dagaut, C.-E. Paillard, S. Gail (2007)
33LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National LaboratoryLLNL-PRES-123456
Key component interactions identified
n-alkane
R
RRLong unsaturated chain promotes low temperature reactivity
n-alkene
Double bonds act as radical
scavenger –
allylic sites depress
reactivity
toluene
Iso-alkane
Primary sites reduce reactivity –
substitutions on the chain interfere with isomerizations
Abstraction on the benzylic site generates stable radicals –
suppresses reactivity
34LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National LaboratoryLLNL-PRES-123456
HCCI engine results:
0
5
10
15
20
25
30
330 335 340 345 350 355 360 365Crank Angle [°CA]
Hea
t-R
elea
se R
ate
[J/°C
A]
0
5
10
15
20
25
30
330 335 340 345 350 355 360 365Crank Angle [°CA]
Hea
t-Rel
ease
Rat
e [J
/°CA
]
0
5
10
15
20
25
30
330 335 340 345 350 355 360 365Crank Angle [°CA]
Hea
t-Rel
ease
Rat
e [J
/°CA
]
PRF80 Experimental
PRF54 2002 Mechanism
PRF68 2008 Mechanism
1050 rpm1200 rpm1300 rpm1400 rpm1500 rpm1600 rpm1700 rpm
a)
b)
c)
(Dec and SjöbergSandia)
New 2008 mechanism
2002 mechanism
PRF80fueling
Better simulation of heat release rate
35LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National Laboratory
phenol
PRF80 Initial Species Results
•
Greater than 50 identifiable species in the
exhaust
•
Similarity to results from iso‐octane and
Chevron‐Phillips Reference Gasoline•
Many species in common, but relative amount
varies
•
Larger distribution of oxygenated species in
near‐misfire exhaust conditions
PRF80
PRF80
Major exhaust species besides unburned fuel
2-methyl-1-propene
Hydrocarbons
Oxygenated hydrocarbons
36LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National LaboratoryLLNL-PRES-123456
O
O
We collaborate with others to reduce our models for use in reacting flow codes
3036 species8555 reactions
125 species712 reactions
0
10
20
30
40
50
60
70
0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5
Equivalence ratio
Flam
e sp
eed
[cm
/sec
]
Model: methyldecanoate
Experiments: n-decane (Huang, Sung, and Eng, CF 2007)
Fuel/O2/N2
1 atm360KN2/O2=3.76 (air-like diluent)
Laminar flame speeds of MD compare well with n-
decane
Tianfeng Lu and C. K. Law, 2009
940 species3887 reactions
211 species794 reactions
n-decane Methyl-decanoate, biodiesel surrogate
Niemeyer, Raju and Sung, 2009
37LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National Laboratory
We now have state-of-the-art, chemical kinetic models for transportation fuels
Gasoline•
n-heptane
•
iso-octane
Diesel•
n-cetane
•
iso-cetane
Biodiesel
LLNL-PRES-411416
38LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National LaboratoryLLNL-PRES-123456
Mechanisms are available on LLNL website and by email
http://www-pls.llnl.gov/?url=science_and_technology-chemistry-combustion
39LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National Laboratory
Future activities
large alkyl benzene, important component for diesel fuel
gasoline surrogate with ethanol
larger olefins in present gasoline (C5, C6 branched olefins, nC7 olefins) for Advanced Petroleum Based Fuels
actual biodiesel component (methyl stearate) for Non-
Petroleum Based Fuels
Develop detailed chemical kinetic models for:
LLNL-PRES-411416
40LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National LaboratoryLLNL-PRES-123456
Detailed kinetics of gasoline surrogates
High fidelity engine models
testing
tuning
5.88 mm(0.2314 in)
5.23 mm(0.206 in)
9.01 mm(0.355 in)
0.305 mm(0.0120 in)
102 mm(4.02 in)
HCCI is a promising engine operating regime, and is also an excellent platform for developing & testing high fidelity chemical kinetic
models
41LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National Laboratory
Gasoline surrogate model accurately predicts ignition time as a function of equivalence ratio
42LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National Laboratory
But it does not properly replicate ignition time as a function of intake pressure
43LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National Laboratory
Analysis of pressure sensitivity of low temperature reaction steps may offer guidance toward improving quality of agreement
Radical recombinationR + O2
RO2
Chain branchingO2
QOOH HO2
QO + OH
44LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National Laboratory
Increasing the reactivity of the radical recombination reaction R + O2
RO2
matches experimental results up to ~1.7 bar intake
300
350
400
450
0.5 1.0 1.5 2.0 2.5 3.0
RO2 x5Baseline
x5
Intake Pressure [bar]
TBD
C [K
]
45LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National Laboratory
We obtain improved agreement by reducing activation energy of chain branching reactions as a function of pressure
46LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National LaboratoryLLNL-PRES-123456
M. A. Oehlschlaeger, J. Steinberg, C. K. Westbrook and W. J. Pitz, "The Autoignition of iso-Cetane: Shock Tube Experiments and Kinetic Modeling," Combustion and Flame, submitted (2009).
Westbrook, C. K., Pitz, W. J., Herbinet, O., Curran, H. J. and Silke, E. J., "A Detailed Chemical Kinetic Reaction Mechanism for
n-Alkane Hydrocarbons from n-Octane to n-Hexadecane," Combustion and Flame 156 (1) (2009) 181-199.
Mehl, M., Vanhove, G., Pitz, W. J. and Ranzi, E., "Oxidation and
Combustion of the n-Hexene Isomers: A Wide Range Kinetic Modeling Study," Combustion and Flame 155 (2008) 756–772.
Herbinet, O., Pitz, W. J. and Westbrook, C. K., "Detailed Chemical Kinetic Oxidation Mechanism for a Biodiesel Surrogate," Combustion and Flame 154 (2008) 507-528. (2nd
most downloaded paper in Combustion and Flame from July to September 2008).
W. J. Pitz, C. K. Westbrook, O. Herbinet and E. J. Silke, "Progress in Chemical Kinetic Modeling for Surrogate Fuels," (Invited Plenary Lecture), The 7th COMODIA International Conference on Modeling and Diagnostics for Advanced Engine Systems, Sapporo, Japan, 2008.
C. K. Westbrook, W. J. Pitz, H.-H. Carstensen and A. M. Dean, "Development of Detailed Kinetic Models for Fischer-Tropsch Fuels," 237th ACS National Meeting & Exposition, Salt Lake City, Utah, 2009.
Dec, J.E., M.L. Davisson, M. Sjöberg, R. Leif, W. Hwang, 2008, Detailed HCCI exhaust speciation and the sources of hydrocarbon and oxygenated hydrocarbon emissions, SAE Congress Paper Number 2008-01-0053.
Seshadri, K., Lu, T., Herbinet, O., Humer, S., Niemann, U., Pitz, W. J. and Law, C. K., "Ignition of Methyl Decanoate in Laminar
Nonpremixed Flows," Proceedings of the Combustion Institute 32 (2009) 1067-1074.
Sakai, Y., Miyoshi, A., Koshi, M. and Pitz, W. J., "A Kinetic Modeling Study on the Oxidation of Primary Reference Fuel-Toluene Mixtures Including Cross Reactions between Aromatics and Aliphatics," Proceedings of the Combustion Institute, 32 (2009) 411-418.
Westbrook, C. K., Pitz, W. J., Curran, H. J. and Mehl, M., “The Role of Comprehensive Detailed Chemical Kinetic Reaction Mechanisms in Combustion Research”
in:M. Dente, (Eds), Chemical Engineering Greetings to Prof. Eliseo Ranzi on Occasion of His 65th Birthday, AIDIC (Italian Association of Chemical Engineering) with the cultural partnership of Reed Business Information, 2008.
Westbrook, C. K., Pitz, W. J., Westmoreland, P. R., Dryer, F. L., Chaos, M., Osswald, P., Kohse-Hoinghaus, K., Cool, T. A., Wang, J., Yang, B., Hansen, N. and Kasper, T., "A Detailed Chemical Kinetic Reaction Mechanism for Oxidation of Four Small Alkyl Esters in
Laminar Premixed Flames," Proceedings of the Combustion Institute, 32 (2009) 221-228.
C. K. Westbrook, W. J. Pitz, M. Mehl and H. J. Curran, "Detailed
chemical kinetic models for large n-alkanes and iso-alkanes found in conventional and F-T diesel fuels," U.S. National Combustion Meeting, Ann Arbor, MI, 2009.
M. Mehl, H. J. Curran, W. J. Pitz and C. K. Westbrook, "Detailed
Kinetic Modeling of Gasoline Surrogate Mixtures," U.S. National
Combustion Meeting, Ann Arbor, MI, 2009.
Recent Publications
47LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National LaboratoryLLNL-PRES-123456
1.
Pathline Analysis of Full-cycle Four-stroke HCCI Engine Combustion Using CFD and Multi-Zone Modeling, Randy P. Hessel, David E. Foster, Richard R. Steeper, Salvador M. Aceves, Daniel L. Flowers, SAE Paper 2008-01-0048.
2.
Modeling Iso-octane HCCI using CFD with Multi-Zone Detailed Chemistry; Comparison to Detailed Speciation Data over a Range of Lean Equivalence Ratios, Randy P. Hessel, David E. Foster, Salvador M. Aceves, M. Lee Davisson, Francisco Espinosa-
Loza, Daniel L. Flowers, William J. Pitz, John E. Dec, Magnus Sjöberg, Aristotelis Babajimopoulos, SAE Paper 2008-01-0047.
3.
Liquid penetration Length in Direct Diesel Fuel Injection, S. Martínez-Martínez, F.A. Sánchez-Cruz, J.M. Riesco-Ávila, A. Gallegos-Muñoz and S.M. Aceves, Applied Thermal Engineering, Vol. 28, pp. 1756-1762, 2008.
4.
HCCI Engine Combustion Timing Control: Optimizing Gains and Fuel
Consumption Via Extremum Seeking,
N.J. Killingsworth, S.M. Aceves, D.L. Flowers, F. Espinosa-Loza, and M. Krstic, Accepted for publication, IEEE Transactions
On Control Systems Technology, 2009.
5.
Demonstrating Optimum HCCI Combustion with Advanced Control Technology, Daniel Flowers, Nick Killingsworth, Francisco Espinoza-Loza, Joel Martinez-Frias, Salvador Aceves, Miroslav Krstic, Robert Dibble, SAE Paper 2009-01-1885, 2009.
Recent Publications
48LLNL-PRES- 123456 DEER 2009
Lawrence Livermore National Laboratory
•
Lee Davisson (LLNL) in collaboration with John Dec and Magnus Sjöberg, Sandia
•
Expanded sample standards to 25 neat materials, including oxygenated hydrocarbons
•
Developed HPLC method for derivatized C1-C5 aldehydes and ketones
•
Collected and measured HCCI exhaust species using PRF80 fuel in Sandia engine
Pre-mix phi sweep from 0.32 to 0.08 equivalence ratio
Collected several at near misfire conditions
Analytical work 95% complete
Data analysis ongoingo
e.g., comparison to previous gasoline and isooctane results
We have obtained engine speciation data for validation of HCCI KIVA multizone model with detailed chemical kinetics
LLNL-PRES-411416
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Lawrence Livermore National LaboratoryLLNL-PRES-123456
Reactivity for HMN is between those of iso-octane and large n-alkanes
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
0.7 0.9 1.1 1.3 1.5
1000/T [K]
log
[ms]
nc7h16 exptnc7h16 calcnc10h22 calcnc10h22 exptiso-c8h18 calcic8h18 expthmn calc
Iso-octane
n-alkanes
HMN
fuel/airstoichiometric13 bar
Low temperature chemistry region