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Research and Advanced Engineering
1
IC Engine Combustion Research, Development, and Challenges
J. James Yi
Technical Leader and Manager
Combustion System R & D
Ford Motor Company
June 5, 2013
Research and Advanced Engineering
2
�Technology Drivers
�Ford’s Global Technology Migration Strategy
�Ford EcoBoost Combustion system Development
�Future Research Opportunities
�Summary
Outline
Research and Advanced Engineering
3
Aggressive CO2 fleet targets will require advanced technologies for a variety of P/T combinations and vehicle applications.
0
2000 2005 2010 2015 2020 2025 2030 2035Model Year
New
Fle
et
LD
V G
as
oli
ne
Eq
uiv
ale
nt
g C
O2
/ k
m
NA WRE450
NA: Metro-Highway test cycle
EU: NEDC test cycle
EU WRE450
U.S. CAFE / CO2 Standard
U.S. One National Standard
(35.5 mpg in 2016)
New Proposal(54.5 mpg in 2025)
EU Legislation
0
2000 2005 2010 2015 2020 2025 2030 2035Model Year
New
Fle
et
LD
V G
as
oli
ne
Eq
uiv
ale
nt
g C
O2
/ k
m
NA WRE450
NA: Metro-Highway test cycle
EU: NEDC test cycle
EU WRE450
U.S. CAFE / CO2 Standard
U.S. One National Standard
(35.5 mpg in 2016)
New Proposal(54.5 mpg in 2025)
EU LegislationEU Legislation
Future CO2 Requirements
Research and Advanced Engineering
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Emissions Regulations
Along with more stringent Nox and UHC emissions standard, Particulate emissions standards are reaching a level that has an impact not only on diesel vehicles, but also gasoline vehicles.
Emissions Regulations
3
4
5
6
7
150
Stage V
200 250
NOx + HC (mg/km)
PM
(m
g\k
m)
Stage VIIForecast
*
T2B5
Stage VI *2
100
0
1
0 50
SULEV30
*Estimated from particle number
Research and Advanced Engineering
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Ford believes that the IC engine will play a key role in transportation in the near and mid-term and will continue to develop technologies to further extend its potential.
Begin migration to advanced technology
Full implementation of known technology
Continue leverage of Hybrid technologies and deployment of alternative energy sources
�Significant number of vehicles with EcoBoost engines
�Flex Fuel Vehicles
�Increased hybrid applications
�Stop/Start systems (micro hybrids) introduced
�Dual clutch and 6 speed transmissions replace 4 & 5 speeds
�Electric power steering – begin global migration
�Increased unibody applications
�Introduction of additional small vehicles
�Battery management systems –begin global migration
�Aero improvements
�CNG/LPG Prep Engines available where select markets demand
• EcoBoost engines available in nearly all vehicles
• Vehicle capability to fully leverage available renewable fuels*
• Increased application of Stop/Start
• Increased use of Hybrid Technologies
• Introduction of PHEV and BEV
• Diesel use as market demands
�Electric power steering - High volume
�Six speed transmissions - High volume
• Weight reduction of 250 – 750 lbs
• Engine displacement reduction aligned with weight save
• Additional Aero improvements
• Continue improving efficiency of internal combustion engines
• Volume expansion of Hybrid and PHEV technologies
• Continued leverage of BEV
• Continue to develop fuel cells; implementation timing aligned with fuels and infrastructure
• Continued weight reduction actions via advanced materials
2007 2011 2020 2030
Global Technology Migration Strategy
Research and Advanced Engineering
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All-New 6.7L Power Stroke® V8 Turbo Diesel
2011 Super Duty
In the near-term, Ford has been adopting an aggressive strategy for both gasoline and diesel engines to reduce fuel consumption in major markets.
EcoBoost3.5L V6 Gasoline Engine
TaurusSHO
Near-Term CO2 Reduction
Ford Fiesta1.6L I4 Duratorq Diesel Engine
Research and Advanced Engineering
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�Technology Drivers
�Ford’s Global Technology Migration Strategy
�Ford EcoBoost Combustion system Development
�Future Research Opportunities
�Summary
Outline
Research and Advanced Engineering
EcoBoost Principles – Best Brake Thermal Efficiency (BTE)
0 1000 2000 3000 4000 5000 6000
Speed (rpm)
BM
EP
(bar)
20
15
10
5
0
Baseline PFI NA
Peak Power
• Boosting expands the good BTE island
• Downsizing shifts it to area of higher utilization
GTDI Extends the High Efficiency
region as well as the torque curve
Peak Torque
FTP
• FTP Drive Cycle typically centered about the ~25% load point for NA engines.
• For a naturally aspirated engine best BTE is typically about 80% load.
• GTDI greatly expands the best BTE island.
• Downsizing will move the GTDI best BTE island to a useable range.
GTDI
Research and Advanced Engineering
Slide 9
Technical Challenge: DI vs. PFI
1. Cold start crank and run-up emissions are much more challenging in a DI
engine than PFI
2. Over entire speed and load operation map, mixing in a DI engine is much
more challenging than PFI.
3.5L V6 GTDI3.5L V6 PFI
Research and Advanced Engineering
Slide 10
Added Technical Challenge With Turbo DI
3. Turbo DI combustion system is more prone to knock due to higher power
density than naturally aspirated engines.
4. Turbocharging makes engine cold-start even more challenging because it
requires more heat to light off catalyst due to heat loss to the turbo
system.
CAT.
ENGINE
•Extra surface area /
thermal mass due to
turbocharger.
Heat Flux > 2x W/L
Heat Flux > x W/L
Research and Advanced Engineering
Optical Engine
Numerical Modeling
Dyno Testing
Optimized Design
Integrated Up-front Combustion System Optimization Methodology
Research and Advanced Engineering
Slide 12
Series - III
Injector Spray Pattern
Optimization
Optimized Injector
Series - I Series - II
Baseline Injector
1500rpm/5bar
0.0
0.5
1.0
1.5
270 280 290 300 310
SOI (deg. BTDC)
Sm
ok
e (
FS
N)
Baseline Injector Spray Pattern
Optimized Injector Spray Pattern
15o
1500rpm/5bar
0.0
0.5
1.0
1.5
270 280 290 300 310
SOI (deg. BTDC)
Sm
ok
e (
FS
N)
Baseline Injector Spray Pattern
Optimized Injector Spray Pattern
1500rpm/5bar
0.0
0.5
1.0
1.5
270 280 290 300 310
SOI (deg. BTDC)
Sm
ok
e (
FS
N)
Baseline Injector Spray Pattern
Optimized Injector Spray Pattern
15oS
moke (
FS
N)
Research and Advanced Engineering
Optimized Piston
•CA=760
Modeling
Prediction
Optical
Images
Mixture well-centered Mixture off-center
Piston Bowl Geometry Optimization
Baseline Piston
A/F
rich
lean
•CA=760
lean
Rich
Research and Advanced Engineering
Slide 14
Spray-Piston Interaction and Its Impact on Combustion Stability
Research and Advanced Engineering
Slide 15
Spray-Piston Interaction and Its Impact on Combustion Stability
Research and Advanced Engineering
Slide 16
Single Cylinder Optical /
Thermal
Design Optimization Multi Cylinder
•Multi-hole
Spray
•Intake
Port
50+
iterations
<10
iterations
<5
iterations
•Piston
System Development Methodology – Quality & Time
Research and Advanced Engineering
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�Technology Drivers
�Ford’s Global Technology Migration Strategy
�Ford EcoBoost Combustion system Development
�Future Research Opportunities
�Summary
Outline
Research and Advanced Engineering
COCOCOCO2222
NA 4VNA 4VNA 4VNA 4VDOHCDOHCDOHCDOHC
PFIPFIPFIPFI
Proven Proven Proven Proven capabilitycapabilitycapabilitycapability
VariableVariableVariableVariableCamCamCamCamTimingTimingTimingTiming
DIDIDIDIHomogeneousHomogeneousHomogeneousHomogeneous
(incl. CR)(incl. CR)(incl. CR)(incl. CR)
MultiMultiMultiMulti----stage Boostingstage Boostingstage Boostingstage Boosting
FullFullFullFull----range Cooled EGRrange Cooled EGRrange Cooled EGRrange Cooled EGRMax. lowMax. lowMax. lowMax. low----load efficiencyload efficiencyload efficiencyload efficiency
(Lean, HCCI,…)(Lean, HCCI,…)(Lean, HCCI,…)(Lean, HCCI,…)
EcoBoost –Future advancements
Naturally Aspirated pathNaturally Aspirated pathNaturally Aspirated pathNaturally Aspirated path
Under Under Under Under devel.devel.devel.devel.
Increased BMEPIncreased BMEPIncreased BMEPIncreased BMEPAdvanced BoostingAdvanced BoostingAdvanced BoostingAdvanced BoostingKnock mitigationKnock mitigationKnock mitigationKnock mitigation
Improved BTE:Improved BTE:Improved BTE:Improved BTE:---- Cooled EGR Cooled EGR Cooled EGR Cooled EGR
EcoBoost –Technology progression
TurbochargerTurbochargerTurbochargerTurbocharger& Downsizing& Downsizing& Downsizing& Downsizing(architecture)(architecture)(architecture)(architecture)
EcoBoost
EcoBoost – Future Technology Development
Future powertrain versions of EcoBoost will improve fuel economy and emissions capability.
TimeTimeTimeTime
Direct Injection+
Turbocharging+
Downsizing
Research and Advanced Engineering
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• Advanced Gasoline Turbocharged Direct Injection Engine Development
• Joint project w/ Michigan Technological University (MTU)
• Demonstrate by modeling / analysis and with a full-scale vehicle the ability to achieve greater than 25% weighted fuel economy improvement with a gasoline engine / conventional automatic transmission, while meeting T2B2 emissions standard.
Department of Energy Funding Award
Development of advanced EcoBoost technologies will be a major focus.
Cooled EGR
RWFE
Enrichment Zone
BM
EP
Lean Combustion
Advanced
wide range
Boost
IEM T
C
Air
Filter
A/T
Mu
ffler
BFT
LP EGR
Valve
Throttle
EG
R
Co
ole
r
Intake Manifold
Cat
LP EGR Throttle
W
G
Integrated
CAC
CCC TWC(s)
Lean after treatment
Research and Advanced Engineering
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Advanced Combustion Modes
3000
CO-HC
Soo
t-Pro
duct
ion
Soo
t-Pro
duct
ion
NO xProduction
600 1000 1400 1800 2200 26000
1
2
3
4
5
6
Temperature [K]
Equ
iva
len
ce
Ra
tio
Φ=
1/λ
Conv. Path
LTC Path.LTC Path.
HCCI PathHCCI Path
LTC / HCCI
High Efficiency
Low NOx
Low PM
Combustion noise control is critical, but often there is an efficiency-noise tradeoff
Co
mb
. N
ois
e
Fuel Consumption
LTC
Tradeoff
Research and Advanced Engineering
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• Knock limits fuel consumption benefits
– Limits compression ratio
– Forces spark retard and, in the limit, forces enrichment (both limit downsizing potential)
• In the case of knocking condition, only a small portion of fast burn events are with knocking.
Knock Mitigation Via Reducing Cycle-Cycle Variation
Research and Advanced Engineering
Injection and Spray Atomization
-- Example of Flash Boiling
Winter-blend Gasoline, 1 msA DI Spray 12.5 cc/s @ 10 MPa)
20º C1 bar
100 bar
Fuel TemperatureAmbient Pressure
Fuel Pressure
90º C0.5 bar100 bar
1.5 ms PW ~ 14 mg
Research and Advanced Engineering
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SI Particulate Formation
FILM
c≡c
How much liquid fuel reaches the surface?
Is it evaporated by the time the flame passes?
How well do we know the rich zone characteristics?
Rich and Hot
φ > 2
T > 1800 K
•Mixing
Droplets
Film
Bulk Vapor
Near Liquid
•Atomization
•Volatility
•Atomization
•Volatility
•Spray Targeting
•Surface Temp.
Usually easy to avoid
Hard to eliminate
How much fuel actually sticks?
To model PM, we will need to accurately answer a number of open questions.
Unlike diesel engines,
gasoline particulate
formation is not driven by
mixing processes, but
surface wetting.
What is the role of fuel composition? What level of soot formation chemistry detail is appropriate to predict soot yield?
Research and Advanced Engineering
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� The integrated upfront combustion system optimization
process (modeling, optical engine, dyno) is the key to
designing high quality combustion system with high
efficiency; It has been applied in all Ford recent IC
engine development.
� Further understanding of fundamental physics is the key to the advanced combustion system development
– Advanced combustion mode (lean, LTC, RCCI, EGR,…)
– Fuel Injection and spray atomization (flash boiling,…)
– Knock mitigation and Cyclic phenomena understanding and control
– Emissions especially soot emissions formation mechanism and mitigation gasoline engine particulates
– Noise tradeoffs and noise reduction in advanced combustion modes
Summary
Research and Advanced Engineering
Ford/ORNL Combustion
Variation Modeling
26
GOAL
• Most engine modeling provides an “average” cycle, neglecting variation. This work aims to develop an efficient high-performance computational strategy for modeling cyclic combustion variation and begin to understand the triggers for CCV that could be optimized.
Allocated 2 million processor-hours for
development and primary study.
SCOPE
• Adapt sampling algorithm to convert the sequential problem to a massively-parallel study that can utilize TITAN computer system capability.
– Simultaneously launch many CFD simulations with varying boundary
conditions.
– Use LES turbulence models and detailed-chemistry combustion within
CONVERGE to capture details of variation.