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Sloan Automotive Laboratory
Massachusetts Institute of Technology
Cambridge, MA, USA
Sloan Automotive Laboratory
31-153
Massachusetts Institute of Technology
77 Massachusetts Avenue
Cambridge, MA 02139-4307
Phone: (617) 253-4529
Fax:
(617) 253-9453
http://engine.mit.edu
December, 2004
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Sloan Automotive Laboratory
Massachusetts Institute of Technology
Cambridge, MA, USA
• Founded 1929 by Professor C.F. Taylor, with a grant
from A. P. Sloan
• Established as a major laboratory for automotive
research
• Extensive industrial and government funding
• Research areas:
Internal combustion engine
Fundamental combustion studies
Engine/fuel interactions
Engine and fuels technology assessment
Objective: Contribute to future developments in automotive
technology through fundamental and applied
research on propulsion technology and fuels
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Sloan Automotive Laboratory
Faculty and Staff
Professor Wai K. Cheng, Associate Director
Combustion, diagnostics, engine design
Professor William H. Green, Jr. (Chem. Eng.)
Combustion chemistry, fuels
Professor John B. Heywood, Director
Engine combustion, performance and emissions; engine
design
Professor James C. Keck (Emeritus)
Combustion, thermodynamics, kinetics
Dr. Tian Tian
Analysis, lubrication, engine dynamics
Dr. Victor W. Wong, Manager
Lubrication, engine design and operating characteristics
About 25 graduate students are involved in the research
projects
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Sloan Automotive Laboratory
Facilities
12 Test Cells:
• Single cylinder Spark-Ignition engines
• Single cylinder HCCI engine with VVT
• Multi-cylinder Spark-Ignition engines
• Heavy Duty Multi-cylinder Diesel engine
• Optical-access engines with transparent
cylinders for combustion and lubrication
measurements
• Rapid compression machine
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Sloan Automotive Laboratory Facilities:
Special Equipment
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LIF imaging systems
Fluorescence-based lubricant film diagnostic
High-speed digital video camera (1000 frames/s)
Particulate Spectrometer
Gas chromatograph
Fourier transform infrared analyzer
Laser Phase Doppler anemometer
Fast-response FID Hydrocarbon and NOx analyzers
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Current/Recent Research Projects
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Engine and Fuels Research Consortium (DaimlerChrysler, Delphi, Ford,
GM, Saudi Aramco)
Lubrication Consortium (Dana, Mahle, PSA, Renault, Volvo Truck)
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Homogeneous-Charge-Compression-Ignition (HCCI) Engine (DOE)
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Control-Auto-Ignition (CAI) Engine (Ford)
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Plasmatron Enabled SI Engine Concepts (Ford, Arvin Meritor)
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Engine starting strategies (DaimlerChrysler)
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Robust Retarded Combustion (Nissan)
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Clean Diesel Fuels (DOE)
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Oil Aeration Study (Ford)
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Heavy Duty Natural Gas Engine Friction Reduction (DOE)
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Heavy Duty Diesel Engine Wear Reduction (DOD)
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High Speed Engine Lubrication (Ferrari)
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Assessment of Future Powertrain, Vehicle, and Fuels Technology (V.
Kann Rasmussen Foundation, Energy Choices Consortium)
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Industrial Consortium Operation
• Multi-sponsor, multi-year program
– Pre-competitive research agenda
• Regular meetings (every 4 months) to set program
agenda and discuss research findings
• Periodic visits to sponsor companies for discussion
with staff
• Direct technology transfer through exchange of
personal and use of facilities and computer codes
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Engine and Fuels Research Consortium
1982 - present
Current Focus: SI Engines
Members:
DaimlerChrysler Corp.,Delphi Corp., Ford Motor Co.,
General Motors Corp., Saudi Aramco
Current Research Program
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Strategies to reduce engine start up emissions
Fast catalyst light-off strategies
Fundamental study of particulate matters formation
Catalyst behavior: effects of sulfur and age on
effectiveness
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Industrial Consortium on Lubrication in IC Engines
1989 - present
Current Focus: Piston/liner tribology
Members:
Dana Corp., Mahle Corp., Peugeot SA, Renault, Volvo Truck
Current Research Program
• Characterization of lubricant behavior between piston
and liner and its impacts on engine wear, friction and
lubricant requirements
– Quantitative 2D LIF visualization of oil film
dynamics in the piston/liner interface
– Modeling of oil transport/consumption and ring
friction
– Application to ring designs (geometry and tension)
Research High Lights
Drivers for Emissions Research
1975
1977
1975
1
1977
1981
0.1
1994 US
1994 TLEV
1997 TLEV
NOx(g/mile)
NMOG (g/mile)
1
1981
1994 TLEV
1997-2003 ULEV
0.1
1997-2003 ULEV
0.01
2004 SULEV2
2004 SULEV2
1975 1980 1985 1990 1995 2000 2005 2010
Starting year of implementation
0.01
1975 1980 1985 1990 1995 2000 2005 2010
Starting year of implementation
Least square fit:
Factor of 10 reduction in both HC and NOx
every 15 years
1st peak
Integrated HC emissions: 16 mg
2nd peak
55 mg
Total: 71 mg (SULEV:
FTP total is < 110 mg)
Engine start
up behavior
2.4 L, 4-cylinder
engine
Engine starts
with Cyl#2
piston in mid
stroke of
compression
Firing order
1-3-4-2
First fuel pulse
~90 mg/cylinder
First firing:
Cyl#2
First cycle in-cylinder f results (SAE 2002-01-2805)
First Cycle In-cylinder f
4.5
R300 ( 40C, MAP 0.92 bar )
R600 ( 40C, MAP 0.8 bar )
4
R900 ( 40C, MAP 0.7 bar )
80C
R300 ( 60C, MAP 0.92 bar )
3.5
R600 ( 60C, MAP 0.8 bar )
R900 ( 60C, MAP 0.7 bar )
3
R300 ( 80C, MAP 0.92 bar )
R600 ( 80C, MAP 0.8 bar )
60C
R900 ( 80C, MAP 0.7bar )
2.5
R200 ( 20C, Zetec Engine )
R200 ( 0C, Zetec Engine )
2
40C
1.5
RPM Tcoolant
20C
1
0.5
0C
0
0
50
100
Lean Limit of consistent firing
150
200
250
Injected Fuel Mass (mg)
300
350
First cycle fuel delivery efficiency results (SAE 2002-01-2805)
R300 ( 40C, MAP 0.92 bar )
R600 ( 40C, MAP 0.8 bar )
R900 ( 40C, MAP 0.7 bar )
1
R300 ( 60C, MAP 0.92 bar )
R600 ( 60C, MAP 0.8 bar )
Delivery Efficiency ef
0.9
80C
R900 ( 60C, MAP 0.7 bar )
R300 ( 80C, MAP 0.92 bar )
0.8
R600 ( 80C, MAP 0.8 bar )
0.7
R900 ( 80C, MAP 0.7bar )
R200 ( 20C, Zetec Engine )
60C
0.6
R200 ( 0C, Zetec Engine )
0.5
Tcoolant
40C
0.4
RPM
0.3
20C
0.2
0.1
0C
0
0
50
100
150
Injected Fuel Mass(mg)
200
250
300
Effect of delaying IVO on 1st cycle fuel delivery
INCOMING
MIXTURE
INCREASINGLY
LEAN AS PISTON
DRAWS IN
CHARGE
1.2
1.1
1.0
INTAKE
FLOW
LEAN
0.9
0.8
RICH
0.7
PISTON
DISPLACES
MORE LEAN
CHARGE AS
IVC DELAYED
PISTON
0.6
0.5
-20
-10
0
10
20
Intake Valve Opening (CAD from TDC Exhaust)
Injected mass:
132.9 mg
199.3 mg
265.7 mg
Pressure(bar)
or HC mole fraction (%)
Fuel equivalence Ratio ( F)
(SAE 2004-01-1852)
35
HC
30
Pressure
In-cylinder HC
value for F
calculation
25
20
15
10
5
0
0
500
1000
Crank angle
1500
2000
Exhaust port/runner oxidation
with retard spark timing
60
HC Emissions (g-HC/kg-fuel)
50
40
Cylinder Exit [Quenching]
Port Exit [FFID: 7-cm from EV
Runner [FFID: 37-cm from EV
Exhaust Tank 120-cm from EV
30
20
10
0
15
0
-15
Spark Timing (° BTDC)
3.0 bar n-imep, 1500 RPM, l = 1.0, 20°C
Secondary air injection
3.0 bar NIMEP, 1500 RPM, 20° C
lexhaust = 0.85
1.4
Sp = 15° BTDC
HC/HCref
1.2
1.0
0.8
Sp = -15°BTDC
Sp = 0° BTDC
0.6
l = 0.85
l = 1.0
l = 1.1
0.4
0.2
0.5
1.0
1.5
lExhaust=1.4
2.0
2.5
 hs )catalyst
(m
Re f. value
3.0
3.5
4.0
Ref value: at
condition of
15oBTDC spark
and l = 1
NO/NO inlet
1
0.8
Catalyst
performance
4K miles aged
50K miles aged
0.6
150K miles aged
0.4
(SAE 2003-01-1874)
0.2
0
CO/CO inlet
1
0.8
4K miles aged
50K miles aged
150K miles aged
0.6
7 ppm fuel S
1600 rpm
0.5 bar Pintake
Space vel.
- 4.4x104/hr
l modulation
- 2 Hz
- Dl=± 0.025
0.4
0.2
0
HC/HC inlet
1
4K miles aged
0.8
50K miles aged
0.6
150K miles aged
0.4
0.2
0
0
0.2
0.4
0.6
0.8
Fraction of cumulative catalyst volume
1
Time-resolved NO profiles along catalyst (SAE 2003-01-1874)
Aged 4k-miles; 4.4x104/hr space vel.; l modulation: 1Hz, Dl=± 0.03
500
0% cumulative
catalyst vol.
NO (ppm)
250
0
500
250
0
50
17%
25
0
50
33%
25
0
50
50%
25
67%
0
50
25
82%
0
50
100%
25
0
0
2
4
Time (s)
6
8
10
2
1
O storage capacity (g)
2
Normalized O2 Storage
Fuel Sulfur Effect on Oxygen Storage Capacity:
Age effect and fuel S effect are separable
1
Slope:
0.8 10% decrease
0.6
0
in O2 storage
capacity with
every 150 ppm
increase in
fuel S
100
200
300
400
Fuel sulfur (ppm)
500
7ppmS
33ppmS
266ppmS
500ppmS
Power law: O2 storage age- 0.84
10
100
Catalyst age (k-miles)
Plasmatron Fuel Reformer
Developed at the MIT Plasma Science and Fusion Center
Ideal Partial Oxidation Reaction:
n
m
n
plasmatron
Cn H m  O2  3.773N 2  
 nCO  H 2   3.773N 2
2
2
2
Fuel
Air 1
1
Plasmatron
Products of the Ideal
Reaction
Species Mole Fraction
1st Stage
2
Reactor
Air 2
Nozzle
3
Section
Fuel
Air 3
24nd Stage
Reactor
Flow Direction
H2
25%
CO
26%
N2
49%
Effect of Plasmatron gas on lean operation
(1500 rpm, 3.5 bar NIMEP, SAE2003-01-0630)
Overall Net
Indicated
Efficiency (%)
33%
32%
Synth. Plas. gas = 10%
31%
Synth. Plas. gas = 20%
30%
Synth. Plas. gas = 30%
(Assume ideal
Plasmatron
efficiency of 86%)
29%
28%
Indolene Only
27%
1
1.2
1.4
1.6
1.8
2
2.2
Lambda
H2 Add = 10% Equiv
NOx (PPM)
10000
H2 Add = 20% Equiv
1000
H2 Add = 30% Equiv
Synth. Plas. gas = 10%
100
Synth. Plas. gas = 20%
Synth. Plas. gas = 30%
10
1
1.2
1.4
1.6
Lambda
1.8
2
2.2
Indolene Only
ONR Decrease with Plasmatron Reformate
(1500 rpm, 8.5 bar NIMEP, MBT spark timing; SAE 2004-01-0975)
ON of PRF into Engine
at Audible Knock
100
90
80
70
PRF, 0% Plas Fraction
60
15% Plas Fraction
30% Plas Fraction
50
1
1.1
1.2
1.3
1.4
Lambda
1.5
1.6
1.7
1.8
VVT
Engine
for HCCI
operation
Geometric
compression
ratio = 8 to16
Spacer to change geometric compression ratio
Mode Transition Considerations: Drive Cycle
9
8
7
Bmep(bar)
6
5
4
SAE 2002-01-0420
3
2
1
0
-1
-2
0
500
1000
1500
2000
RPM
2500
3000
3500
Details of mode transition
Details of transition
8
e
7
d
6
g
h
Bmep (bar)
5
f
4
c
b
h2
3
m
2
av
1
k
o
i
t
s
0
-1
u
n
0
500
l
r
1000
q
p
1500
-2
Speed (rpm)
HCCI region
j
2000
2500
A non-robust SI-HCCI transition
Pressure (bar)
80
60
40
SI
IVO
20
IVC 210
EVO 495
EVC 700
IV lift
HCCI
80 atdc-i 1st HCCI cycle
185 atdc-i
495 atdc-i
SI assisted
650 atdc-i
cycles
All subsequent
cycles were HCCI
combustion
EV lift
20
0
0
1000
2000
3000
4000
5000
Crank angle (deg.)
(1500 rpm, 15oBTDC spark)
Pressure(bar)
60
50
40
Pressure(bar)
70
60
50
40
30
20
10
0
60
50
40
30
20
10
0
Pressure(bar)
Pressure(bar)
A Knocking transition
60
50
40
30
20
10
0
30
20
10
0
-10
60
61
62
63
Cycle
64
65
66
A Robust SI-HCCI Transition
Pressure (bar)
80
60
40
SI
HCCI
IVO
20 95 atdc-i
IVC 210 10 atdc-i
EVO 495 495 atdc-i
EVC 700 630 atdc-i
IV lift
1st HCCI cycle
All subsequent cycles
in HCCI combustion
EV lift
20
0
0
1000
2000
3000
4000
5000
Crank angle (deg.)
(1500 rpm, 15oBTDC spark)
First HCCI cycle and 10 following ones
55
50
pressure (bar)
45
40
11th
1st
HCCI
cycle
8th
9th
6th
10th
35
4th
7th
5th
3rd
30
2nd
25
20
175
180
185 190 195 200
Crank angle (deg)
205
210
100 cycles after first HCCI cycle
55
50
pressure (bar)
45
1st
HCCI
cycle
40
3rd
35
30
2nd
25
20
160
170
180
190
200
Crank angle (deg)
210
220
Controlling transition using valve timing
7
GIMEP
Valve timing(o atdc exhaust)
Cycle IVC EVO EVC IVO
58
278 492 731 26
59
278 495 658 30
60
236 496 641 54
61
215 494 639 75
62,… 219 493 644 78
6
IMEP(bar)
5
4
3
2
1
0
56
NIMEP
SI
cycles
with
late
IVC
and
late
EVC
58
First HCCI cycle(60); early IVC
Last SI cycle(59); early EVC
60
62
64
Cycle number
66
68
70
Relationship between IMEP and CA-50
5
4.5
4
IMEP(bar)
3.5
3
Gross
2.5
2
Net
Pumping
1.5
1
0.5
0
10
12
14
16
10
20
22
24
CA-50 location (o after TDC compression)
26
28
Nimep (bar)
EVC (ATDC-i) IVC (ATDC-i)
Valve timing scheduling in mode transition
IVC closer to BDC, increase
of compression and
trapped charge mass
300
250
200
800
0
2
4
6
8
10
0
2
4
6
8
10
0
2
4
6
Cycle Number
8
10
700
600
10
5
0
Nimep (bar)
SI/HCCI/SI Transitions
SI
HCCI
SI
Cycle#
Start with SI mode
Transition into CAI mode in cycle# 60
Transition back to SI mode in cycle# 136
Transition into CAI mode in cycle# 177
HCCI
Open loop control: Modulation period at 30 cycles
1500 rpm; modulation period of 30 cycles=2.4 sec
IMEP(bar),fuel mass per cycle(mg)
6
GIMEP
5
4
3
2
Fuel mass x 10
NIMEP
1
0
-1
0
PMEP
50
100
150
200
Cycle no.
250
300
Open loop control: Modulation period at 14 cycles
1500 rpm; modulation period of 14 cycles=1.12 sec
IMEP(bar),fuel mass per cycle(mg)
6
GIMEP
5
4
3
2
Fuel mass x 10
NIMEP
1
0
PMEP
-1
0
50
100
150
200
Cycle no.
250
300
Fuel mass (mg),
F
NIMEP(bar)
Open-loop step response
4
2
0
0
50
100
150
200
250
150
200
250
100
150
Cycle number
200
250
1.6
Fuel massx0.1
1.4
1.2
F
1
0.8
0
50
100
Valve timing
(oABDC)
100
EVC
50
IVC
0
0
50
Closed-loop load controller
i+1th
cycle target
r i+1
Lookuptable
Rate
limiter
u f,i
ui
Σ
Engine
Dui
wi
K
Integrator
ei
Z-2I
r i-1
+
-
y i -1
Z-2I
y i+1
Open-loop behavior
NIMEP
(bar)
F
1.3
NIMEP
4.5
T(oC)
130
120
1.2
4
3.5
T
110
100
RPM
1700
1.1
1600
RPM
3
1500
1
2.5
F
2
0
0.9
100 200 300 400 500 600 700 800 900 1000
Engine Cycle
1400
1300
Closed-loop behavior
F
1.3
NIMEP
(bar)
4.5
T(oC)
NIMEP
1.2
130
4
120
3.5
110
3
T
RPM
RPM
1.1 1700
1600
1
100
2.5
2
0
F
0.9
100 200 300 400 500 600 700 800 900 1000
Engine Cycle
1500
1400
1300
LIF Oil Distribution Image
No load (1 N.m) - Coolant 50 °C - Oil 50 °C
Expansion stroke
7 mm
20 mm
Fluorescence intensity profile
Ring Pack Geometry
crown land
skirt
Top Ring Up-Scraping Effect (1)
1700 rpm - No load (1 N.m), Coolant 50 °C - Oil 50 °C
Compression stroke
Late compression stroke
Ring Twist
+
Piston Tilt
Anti-Thrust
Side
Transport on the land: INERTIA
INERTIA
Early Upward Stroke
Exhaust & Compression
Stroke
Exhaust stroke
INERTIA
Compression stroke
1200 rpm - No load (1 N.m) - Coolant 50 °C - Oil 50 °C
Transport on the land in
CIRCUMFERENTIAL DIRECTION
1200 rpm - No load (1 N.m) - Coolant 50 °C - Oil 50 °C
Compression
stroke
t=0s
3 mm
t=1s
(10 cycles)
t=2s
(20 cycles)
6 mm
Circumferential Oil Flow
Oil Transport through the Ring Gaps and Mist generation
Scraper Ring
Break up into mist by high velocity
gas flow (liquid entrainment)
Top Ring
Liquid oil
Ring
Land 1
PCV
3. gas ~ 2
Qoil  Qgas 
 h oil
2
h gas .oil
Ring
Land 2
Width of
the gas flow
B. Thirouard
Oil dragged from the piston may be entrained
into mist. Oil mist is carried by gas flow going
to crankcase or back to the combustion
Chamber.
Ring Pack simulation code structure
GAS FLOW
and
RING DYNAMICS
PISTON SECONDARY
MOTION
RING - LINER
LUBRICATION
OIL TRANSPORT
and
OIL CONSUMPTION
Ring/Groove Interface
Gas Flows
asperity contact
Major Elements
of the Existing
Ring Pack Models
RING
oil
Through gaps
Through groove
GROOVE
area in direct asperity contact
oil squeezing
pgas
oil
[1]
Rail/Expander Interaction
Forces and pressures
from the Expander/Spacer
CG
[2]
Ring/Liner Interface
Mixed Lubrication
Three Lubrication Modes
Outlet conditions
Flow continuity
Through waviness
Through bore
Dynamics of the Rings
Oil Consumption Analysis Package
Fundamental Models
RINGPACK-OC
FRICTION-OFT
TLOCR
TPOCR
PISTON2nd
Individual Oil Transport Processes and models
Zone Analysis
Ring/Liner
Scraping
Redistribution
Ring/groove
Pumping out
Gas flow dragging
Piston lands
Gas flow driven
Inertia driven
Vaporization
On liner
On piston
Gap
Gap position
Mist
Research highlights: Integration of modeling and the Experiments on production and single-cylinder engines
Transient oil consumption and Mechanism
Modeling
Measurements from the
Production Engine
1000
4200 rpm; 0 % - WOT
900
60
Oil Cons.
700
Blow-By
600
Air flow
40
500
400
300
20
Blow-By [l/min],
Air Flow[l/s]
200
100
0
80
120
160
Time [s]
200
0
240
10
0
-360
Normalized Lift [1=top position]
Oil Cons. [g/cyc]
800
40
Pres. 1
Pres. 2
Cylinder
2nd Land [pred.]
3rd Land [pred.]
100 % Load
Pressure [bar]
0%
20
-300
-240 -180
-120
-60
0
60
CA [degrees]
120
180
240
300
360
1
0.9
Top Ring
0.8
2nd Ring
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0
180
CA [degrees]
360