Variable Valve Actuation (VVA) - Cnam

Transcription

MULTIDISCIPLINARY UNIVERSITY
1962
2013
11 Faculties
Faculty of Mechanics and Technology,
Faculty of Electronics, Communications and Computers,
Faculty of Sciences, Faculty of Mathematics, Faculty of Letters, Faculty of Social Sciences, Faculty of Economics,
Faculty of Law and Administration, Faculty Physical Education and Sports, Faculty of Theology, Faculty of Education Sciences
2013
~ 12 000 students in bachelor and master degrees,
~ 200 PhD students,
Teaching & Research personal ( ~ 600 persons)
organize
THE ONE DAY SCIENTIFIC WORKSHOP
entitled
Variable Valve Actuation (VVA).
A technique towards more efficient engines
18 April 2013
University of Pitesti, Romania
Amphitheatre CC1, B-dul Republicii nr. 71, Pitesti
OPENING SPEECHES
Mihai BRASLASU
– Vice Rector of the University of Pitesti, Romania
Thierry MANSANO
– Head of Engine Calibration Department of Renault Technologie Roumanie (DCMAP - RTR)
Pierre PODEVIN
– Cnam Paris, LGP2ES, EA21, France. Co-organizer
Adrian CLENCI
– Head of Automotive and Transports Department – University of Pitesti, Romania. Organizer
organize
entitled
PROGRAMME
18 April 2013
10h00 – 11h00: Giovanni CIPOLLA, Politecnico di Torino, Italy, former GM Powertrain.
Variable Valve Actuation (VVA): why?
11h00 – 12h00: Eduard GOLOVATAI SCHMIDT, Schaeffler Technologies AG, Germany.
Consistent Enhancement of Variable Valve Actuation (VVA)
12h00 – 13h30:
Lunch Break
14h00 – 15h00: Stéphane GUILAIN, Renault France, Powertrain Design and Technologies Division.
VVT/VVA and Turbochargers: which synergies can we expect from these technologies?
15h00 – 16h00: Hubert FRIEDL, AVL GmbH Austria, Powertrain Systems Passenger Cars.
Trends in Applications of VVA Systems for Fuel Efficient Powertrain
16h00 – 16h30:
Coffee Break
16h30 – 17h30: Romain Le FORESTIER, VOLVO Powertrain, France.
Advanced combustion and heavy duty engine integration of a hydraulic camless system
17h30 – 18h30: Adrian CLENCI, University of Pitesti, Romania, Pierre PODEVIN, Le Cnam de Paris, France.
VVA technique as a way to improve Spark Ignition Engine efficiency. Results obtained at the University of Pitesti
The Scientific Workshop
A technique towards more efficient engine
WHY ORGANISING?
HISTORY
of
VARIABLE VALVE ACTUATION at UNIVERSITY of PITESTI
1977: a mechanical cam phasing device (VVT) applied on the gasoline engine of the 4WD ARO vehicle by
Professor Vasile Dumitrescu and his team;
1977 - 1990: various VVA solutions were created and tested by Professor Vasile Dumitrescu and his team
1985 - 1990: various VVA solutions by Professor Dumitru Cristea and his team:
- variable intake valve lift mechanism by rocker arm’s variable length;
- cylinder deactivation by intake&exhaust valves deactivation
1985 – present: several Continuous Variable intake Valve Lift mechanisms were developed by
Professor Vasile Hara and his team
Variable intake Valve Lift
by
UNIVERSITY of PITESTI & le Cnam de Paris
1985 – 1990: 2 engine prototypes (4 in-line cylinders gasoline engine) were built with the aid of Dacia plant
2005: re-launching the research on ViVL by Hara&Clenci in cooperation with le cnam de Paris
A carburetor engine featuring
manual actuation of intake valve law
A single point injection engine featuring
automatic actuation of intake valve law
by
UNIVERSITY of PITESTI & le Cnam de Paris
March 2006: successful operational tests of the throttle-less engine at idle operation
The single point injection engine featuring throttle-less control thanks to the ViVL
Stable idle operation @ 800 rpm & λ = 1.6 (lean mixture)
by
UNIVERSITY of PITESTI and le Cnam de Paris
October 2006 - August 2007: adaptation of a multi-port fuel injection system (intake and exhaust on the
same side of the cylinder head)
by
2008: adaptation of the prototype ViVL engine on a Dacia Logan car
Ecologic Vehicle by Intake Throttle-less Actuation
by
September 2012 – April 2013: adaptation of a crossflow engine head (hemispheric combustion chamber)
by
1985 - ……. - present
A side mounted camshaft and
overhead valves version featuring
wedge type combustion chamber
An overhead camshaft version featuring
bowl-in piston combustion chamber
A crossflow engine head featuring a side
mounted camshaft and overhead valves version
featuring pent-roof combustion chamber
organize
entitled
PROGRAMME
18 April 2013
10h00 – 11h00: Giovanni CIPOLLA, Politecnico di Torino, Italy, former GM Powertrain.
Variable Valve Actuation (VVA): why?
11h00 – 12h00: Eduard GOLOVATAI SCHMIDT, Schaeffler Technologies AG, Germany.
Consistent Enhancement of Variable Valve Actuation (VVA)
12h00 – 13h30:
Lunch Break
14h00 – 15h00: Stéphane GUILAIN, Renault France, Powertrain Design and Technologies Division.
VVT/VVA and Turbochargers: which synergies can we expect from these technologies?
15h00 – 16h00: Hubert FRIEDL, AVL GmbH Austria, Powertrain Systems Passenger Cars.
Trends in Applications of VVA Systems for Fuel Efficient Powertrain
16h00 – 16h30:
Coffee Break
16h30 – 17h30: Romain Le FORESTIER, VOLVO Powertrain, France.
Advanced combustion and heavy duty engine integration of a hydraulic camless system
17h30 – 18h30: Adrian CLENCI, University of Pitesti, Romania, Pierre PODEVIN, Le Cnam de Paris, France.
VVA technique as a way to improve Spark Ignition Engine efficiency. Results obtained at the University of Pitesti
Equipe d’accueil EA21
Chimie moléculaire, génie des procédés et énergétique Le 18 avril 2013 Le directeur M. le professeur Ionel DIDEA
Recteur de l'Université de Pitesti
1, Targu Din Vale ‐ Pitesti
11040 ‐ Arges
Objet : Variable Valve Actuation (VVA), A technique towards more efficient engines
18 April 2013 at the University of Pitesti, Romania
M. le Recteur, Mesdames, Messieurs et chers collègues, Cher Mesdames et Messieurs, Je voudrais remercier l'Université de Pitesti et particulièrement A. Clenci de nous associer a cette manifestation. er
La réduction de consommation de carburant est un objectif primordial de 1 plan. La distribution variable (VVA) constitue l’une des possibilités opérationnelles pour améliorer les performances du moteur et réduire les émissions polluantes. A l'instigation du département Automobiles et Transports de l'Université de Pitesti et de l’équipe de turbomachines et moteurs du Cnam, une collaboration entre nos établissements a été engagée dès 1999 dans le domaine des moteurs à combustion interne et des machines thermiques appliqués au transport de surface. Le fruit de cette collaboration a significativement été développé et confirmé au cours de la décennie écoulée par des conventions cadre reconduites régulièrement entre nos deux établissements en adéquation avec nos missions respectives : la formation à distance, la recherche technologique et l’innovation, la diffusion de la culture scientifique et technique. Recherche et diffusion des connaissances La participation au titre de chercheurs associés de l’Université de Pitesti à notre laboratoire (EA21) est soutenue par nos établissements qui se sont impliqués dans ces programmes en finançant plusieurs brevets. Deux thèses en cotutelle ont également été soutenues (2006 et 2012). Ces travaux conduisent régulièrement à des publications communes et à des communications dans des congrès internationaux. Il convient de souligner deux conférences réalisées dans le cadre des visioconférences annuelles organisées par le Cnam et ayant pour thème le moteur à taux de compression variable et la distribution variable. Un article conjoint a été publié récemment dans la collection les Techniques de l'Ingénieur. Je remercie également le collectif du réseau commun de compétences qui est appuyé de manière pérenne par les partenaires ADEME, EURECO, ERASMUS, OSEO et CNCISM. L’agence d’évaluation de la recherche et l’enseignement supérieur français (AERES) a également encouragé début
2013 notre laboratoire à amplifier encore les synergies communes à nos établissements. er
Je vous souhaite un excellent « work shop » qui constitue un événement de 1 plan et qui sans nul doute sera suivi de
nouvelles actions internationales pérennes communes à l’ensemble de la profession. Vous pouvez compter sur mon
appui actif et de celui de l’ensemble du laboratoire. Je vous souhaite, M. le recteur, mesdames, Messieurs et chers collègues un excellent séminaire. Bien cordialement, Georges Descombes Paris, le 18 avril 2013
International committee
Prof. G. DESCOMBES - Cnam - France
Prof. G. DUMITRASCU - UTI - Roumanie
Prof. M. FEIDT – U de Lorraine – France
Prof. C. FERROUD – Cnam - France
Prof. D. GENTILE - Cnam - France
Prof. B. HORBANIUC - UTI - Roumanie
Prof. I. IONEL - UPT – Roumanie
Prof. V. LAZAROV - TUS - Bulgarie
Prof. C. MARVILLET - Cnam - France
Prof. G. POPESCU - UPB - Roumanie
Prof. C. PORTE - Cnam - France
Prof. D. QUEIROS-CONDE - U Paris Ouest - France
Prof. I. SIMEONOV - BAS - Bulgarie
Siteweb :
http://turbo-moteurs.cnam.fr/cofret2014/
Contact :
cofret2014@cnam.fr
Topics of the congress
1. Thermodynamics - Heat and mass transfer
Combustion and gas dynamic
2. Process Engineering
3. Thermal machines
4. Renewable and low-carbon energy, Polygeneration,
Electricity as energy carrier, Energy storage,
Management and control of energy flow,
Economy and Energy
5. Environment and Sustainable Development,
Recycling, New Energy Resources
6. Green chemistry
7. Environmental education and training
Environmental legislation
Siteweb :
Contact :
cofret2014@cnam.fr
Thèmes du colloque
1. Thermodynamique , Transfert de chaleur
et de masse, Combustion et Gazodynamique.
2. Génie des Procédés.
3. Machines thermiques.
4. Energie renouvelables et décarbonée, Polygénération,
Electricité vecteur énergétique, Stockage de l’énergie,
Gestion et contrôle des flux d'énergie,
Economie et Energétique.
5. Environnement et Développement Durable, Recyclage,
Nouvelles Ressources Energétiques.
6. Chimie verte.
7. Enseignement et formation environnemental
Législation environnementale .
Siteweb :
Contact :
cofret2014@cnam.fr
DE
ETC
Development
Engineering Consulting
for Energy in Torino
Exploratory Workshop:
“Variable Valve Actuation (VVA).
A technique towards more efficient engines”
Giovanni Cipolla
GM-PoliTo Institute for Automotive Research & Education (IARE) Director
Politecnico di Torino, Italy
DE
ETC
by G. Cipolla
18 April 2013
1
Variable Valve Actuation (VVA) : WHY ? Lecture topics :

ICE (Internal Combustion Engine) control requirements

Vxy (Variable systems) needs & options in Automotive ICEs

VVA (Variable Valve Actuation) rationales for ICE
DE
ETC
by G. Cipolla
18 April 2013
2



DE
ETC
by G. Cipolla
18 April 2013
3
ICE ‐ 4T (4 strokes) operation
DE
ETC
by G. Cipolla
18 April 2013
4
Otto, Diesel & Sabathè cycles thermodynamic efficiency vs CR (Compression Ratio)
Thermodynamic efficiency
Spark Ignition (SI)
engines
to
Ot
c
hè cy
t
a
b
Sa
le
c
el cy
s
e
i
D
cle
y
c
le
Compression Ignition (CI)
engines
Compression Ratio (CR)
DE
ETC
by G. Cipolla
18 April 2013
5
Intake flow behavior vs crank angle
over engine speed range
Int. valve closing shift
Int/Exh valves overlap
Air velocity [m/s]
EVC
Int/Exh
valves overlap
Int. valve closing shift
Crank angle [°]
Rejected flow
Back flow
DE
ETC
by G. Cipolla
18 April 2013
6
“Full Load” ICE operation conditions
Torque
Power
Power
Torque
Speed (rpm)
DE
ETC
by G. Cipolla
18 April 2013
7
Efficiencies trends of ICE [ f (rpm, pme) ]
vol
comb
vol
comb
Efficiency
mech
DE
ETC
mech
by G. Cipolla
total
total
bmep (bar)
rev’s (rpm)
18 April 2013
8
IC Engine map (i.e. “overall efficiency” or “specific fuel consumption”)
DE
ETC
by G. Cipolla
18 April 2013
9
Areas of ICE in‐vehicle operating conditions on Engine map
TORQUE
“Usual”
& Urban/Extra‐urban driving
“Performance”
& Motorway driving
Homologation Driving Cycle
RPM
DE
ETC
by G. Cipolla
18 April 2013
10



DE
ETC
by G. Cipolla
18 April 2013
11
ICE control “3 layers variability & control” scenario
for in‐vehicle ICE optimization
Throttle
Fuel CR
Turbo
Exhaust
DE
ETC
by G. Cipolla
18 April 2013
Mani‐
folds
Valves
12
Variable Compression Ratio (VCR)
DE
ETC
by G. Cipolla
18 April 2013
13
Throttling & Throttle Body
DE
ETC
by G. Cipolla
18 April 2013
14
Variable Intake System (VIS)
DE
ETC
by G. Cipolla
18 April 2013
15
Variable Geometry Compressor (VGC)
OVERSPEED
SURGE
CHOKING
DE
ETC
by G. Cipolla
18 April 2013
16
Variable Valve systems (VVx)
 VVT (Variable Valve Timing): motion of cam phasing device
 VVL (Variable Valve Lift): switching to different cam profiles
 VVA (Variable Valve Actuation): combined VVT & VVL features
 Camless actuation
Phasing
DE
ETC
by G. Cipolla
{
electromagnetic systems
electrohydraulic systems
Duration
18 April 2013
Lift
Phasing, Lift and
Opening Duration
17
Waste Gate Turbo (WGT) DE
ETC
by G. Cipolla
18 April 2013
18
Variable Geometry Turbine (VGT)
DE
ETC
by G. Cipolla
18 April 2013
19
Exhaust Gas Recirculation (EGR)
Inlet Throttle
VGT Turbocharger Aftertreatment system
C
T

 DUAL
DUALLOOP
LOOPEGR
EGRSYSTEM
SYSTEM
Intercooler
Air
clea
ner AFM
EGR Valve

 LOW
LOWPRESSURE
PRESSUREEGR
EGRSYSTEM
SYSTEM

 HIGH
HIGHPRESSURE
PRESSUREEGR
EGRSYSTEM
SYSTEM
DE
ETC
by G. Cipolla
18 April 2013
20
Volumetric efficiency
Variable Exhaust System (VES)
“4 in 1”
manifold indipendent pipes
Engine speed (RPM)
DE
ETC
by G. Cipolla
18 April 2013
21



DE
ETC
by G. Cipolla
18 April 2013
22
Longitudinal sound waves in air & gas
DE
ETC
by G. Cipolla
18 April 2013
23
ICE like Organ‐Trumpet‐Trombone music instruments
DE
ETC
by G. Cipolla
18 April 2013
24
ICE wave generation & matching with pipe frequency
Pressure waves situation
at ICE “design point” rev’s
DE
ETC
by G. Cipolla
18 April 2013
25
Pressure waves matching during gas exchange
over the whole ICE speed range
Pressure waves situation
out of ICE “design point” rev’s
DE
ETC
by G. Cipolla
Valve timing sensitivity on ICE fuel economy & emissions
18 April 2013
26
Variable Valve systems (VVx)
Phasing
Duration
Phasing, Lift and
Opening Duration
Lift
DE
ETC
by G. Cipolla
18 April 2013
27
WOT torque shaping
VVT High performance (over whole speed range)
“narrow” overlap
High low‐end torque (for driveability)
“large” overlap
High max power
(for performance)
DE
ETC
by G. Cipolla
large
18 April 2013
narrow
28
Unthrottled load control
Conventional throttling
DE
ETC
by G. Cipolla
Early intake valve closing
18 April 2013
29
Charge motion, Kinetic energy and Combustion optimization by means of Swirl & Tumble control
Flow field
(throttled)
DE
ETC
by G. Cipolla
K‐epsilon
(VVA)
18 April 2013
30
“effective” VCR effect (at fixed “geometrical” CR) by means of IVC shift
Influence of Intake Valve Closing (IVC) on effective compression ratio at low speed
DE
ETC
by G. Cipolla
18 April 2013
31
Operation with Miller Atkinson cycle (i.e. ER > CR)
18 April 2013
by G. Cipolla
32
Internal EGR
Valve lift [mm]
1.
2.
a post-opening of the exhaust valve during the intake phase
a pre-opening of the intake valve during the exhaust phase
10
9
8
7
6
5
4
3
2
1
0
1
3
Valve lift [mm]
0
90
180 270 360 450 540 630 720
CA [deg]
10
9
8
7
6
5
4
3
2
1
0
3
0
DE
ETC
90
2
180 270 360 450 540 630 720
CA [deg]
by G. Cipolla
18 April 2013
33
Emissions, fuel consumption & performance trade‐off (by IVC control)
DE
ETC
by G. Cipolla
18 April 2013
34
Engine‐Brake effect (for Diesel)
Valve lift (mm)
INTAKE
NORMAL OPERATION
EXHAUST
ENGINE BRAKE OPERATION
Engine crank angle (CA)
DE
ETC
by G. Cipolla
18 April 2013
35
Variable Valve Actuation (VVA) : Closing Remarks
VVA systems offer great opportunities to fulfill such requirements with relatively simple, reliable & economic engineering solutions
DE
ETC
by G. Cipolla
18 April 2013
36
DE
ETC
Development
Engineering Consulting
for Energy in Torino
Exploratory Workshop:
“Variable Valve Actuation (VVA).
A technique towards more efficient engines”
Giovanni Cipolla
GM-PoliTo Institute for Automotive Research & Education (IARE) Director
Politecnico di Torino, Italy
DE
ETC
by G. Cipolla
18 April 2013
37
Consistent Enhancement
of Variable Valve Actuation
Prof. Dr.-Ing. Kurt Kirsten, Eduard Golovatai-Schmidt
Research & Development, Engine Systems Division
Schaeffler AG & Co. KG
Consistent Enhancement of Variable Valve Actuation
Agenda
1
Motivation to Use Variable Valve Trains
2
Process of Conventional Combustion Engines
3
Overview of Different Variable Valve Trains
4
Degree of Improvement of Conventional Combustion Engines
5
Variable Valve Train in Combination with Sequential Turbocharging
6
Conclusive Remarks
Universitatea Pitesti, 18.04.2013
Page 2
Agenda
1
2
3
4
5
6
Conclusive Remarks
Page 3
Motivation to use Variable Valve Trains
Grams CO2 per Kilometer NEDC test
Mean Values for CO2 Emissions
270
Actual Data
250
Nearest Targets
Enacted
230
Proposed Targets
210
Australia
190
USA
China
170
EU
150
South Korea
130
Japan
110
90
2002
2004
2006
2008
2010
2012
2014
2016
2018
2020
Based on ICCT March 2010
Page 4
Efficiency Chain in a Gasoline Engine
100%
100%
89%
89%
Crude Oil
Petrol
Station
87%
87%
Engine
32%
32%
Mechanical Energy
after Combustion
21%
21%
18%
18%
14%
14%
Mechanical
Energy
Tyres
Propulsion
ENERGY
-4% Braking Losses
-3% Powertrain Losses
-2,5% Auxiliary Drive
-8,5% Friction
Sphere of Influence
of Valve Train
-25% Heat Losses Exhaust Gas
-25% Heat Losses Coolant
-5, -8 % Charge Cycle
-2% Convection
-11% Raffinery/Transport
Page 5
Agenda
1
2
3
4
5
Variable
Valve
Train in Combination with Sequential Turbocharging
Conclusive
Remarks
6
Conclusive Remarks
Page 6
Technologies for future Gasoline Engines
Variable Charge
Motion
Variable Valve
Actuation
GDI
Stratified
Improved
Engine
Efficiency
Controlled
Auto-ignition
Auto-ignition
Cylinder
Deactivation
Super / Turbo
Turbo-Charging
Reduced
parasitic
losses,
improved
energy
management
Shifting of
Operation
Points
Page 7
Most of the Gasoline
engine technologies
under development
are heading for
improved thermal
efficieny
Improved friction and
energy management
as add-on to any
technology
Variable Valve
Actuation
GDI
Stratified
Controlled
Auto-ignition
Auto-ignition
Naturally Aspired Engine
20
18
Super / Turbo
Turbo-Charging
20
18
16
14
14
12
12
10
10
8
8
120km/h
90km/h
120km/h
6
90km/h
4
4
2
2
0
1.000 2.000 3.000 4.000 5.000 6.000
0
1.000 2.000 3.000 4.000 5.000 6.000
Engine Speed [rpm]
Page 8
Charged Engine
16
6
Cylinder
Deactivation
BMEP [bar]
Variable Charge
Motion
BMEP [bar]
Fuel Economy Improvement by Shifting of Operation Points
Engine Speed [rpm]
Agenda
1
2
3
different Variable
Overview of Different
Variable Valve
Valve Trains
Trains
4
5
Variable
Valve
Conclusive
Remarks
6
Conclusive Remarks
Page 9
Motivation and Basics
Mean Consumption Values for CO2
Emissions
Loss Distribution
max
Throttled
De-Throttled
 bLaWe
 bLaWe
Friction
 bWW
Charge Cycle
 bPA
min
Page 10
Process
Torque
Required Variabilities
A
A
B
Max. Torque
Max. Power
Maximum Volumetric Efficiency
Early Closure (Short Valve Event)
C
Full Lift
Late Closure
Greater Overlap
Optimization of Pumping Losses
Optimization of Pumping Losses
(Combustion Optimization)
F
D
Combustion Optimization
(Charge Motion)
Engine Speed
Page 11
Miller
Atkinson
Port Deactivation
IC’
Valve Phasing
IC
Cylinder Deactiv.
Event Length
De-Throttling Concept
Improved Cycle (Cooling Effect  EIC)
Page 12
Miller
Atkinson
IC’
Port Deactivation
Valve Phasing
IC
Cylinder Deactiv.
Event Length
De-Throttling Concept
Excess Gas Mass is recharged during
Compression
Page 13
Miller
Atkinson
Port Deactivation
Valve Phasing
Conventional
Intake Port Pool
Swirl
Port
Cylinder Deactiv.
Event Length
Stable and effective Combustion
Page 14
Miller
Atkinson
Port Deactivation
Valve Phasing
Swirl
Port
Conventional
Intake Port Pool
IC’
Cylinder Deactiv.
Event Length
Combination of De-Throttling and Charge
Motion
Page 15
IC
Swirl Number and Flow Coefficient Mappings
Flow Coefficient αk
Swirl Number cu / ca [-]
8
8
7
6
2.5
2.5
6
3.0
3.0
5
3.5
3.5
4.0
4.0
5
4
5.0
5.0
6.0
6.0
7.0
7.0
8.0
8.0
4
3
3.5
3
2.5
2
2
2.5
2.5
1.5
1
2.0
2.0
1.0
1.0
0
0
1
1
1.5
1.5
2
0.10
0.100
0.100
7
Valve Lift Swirl Port [mm]
Valve Lift Swirl Port [mm]
8
2.0
2.0
7
0.09
0.090
0.090
6
0.08
0.080
0.080
0.07
5
0.070
0.070
0.06
0.060
0.060
4
0.05
0.050
0.050
3
0.04
0.040
0.040
0.03
0.030
0.030
2
0.020
0.020
0.02
1
0.010
0.010
0.01
0
3
4
5
6
7
8
Valve Lift Charge Port [mm]
0
1
2
3
4
5
6
7
8
Valve Lift Charge Port [mm]
Source: Carsten Kopp, Dissertation 2006, Magdeburg
Page 16
Miller
Atkinson
be max
be min
Port Deactivation
be min
Valve Phasing
Cylinder Deactiv.
Drag Curve
be min
Event Length
Shift of Area of Operation
De-throttling and Improvement in High Cycle
Efficiency
Page 17
Miller
Atkinson
Cylinder 1
Cylinder 3
Port Deactivation
Cylinder 4
Exhaust Gas
Reverse Flow
Valve Phasing
Cylinder Deactiv.
PSR
PExhaust Gas
Event Length
Intake
Opening
Exhaust
Closing
Avoid Interacting of Exhaust Ports (I4 Engine)
Improve EGR Scavenging
Page 18
Overview of Valve Train Variabilities
Variable Valve Train
Lift and Timing
Phasing
Continuous
Discrete (switchable)
Continuous
Hydraulic
Electro-Mechanical
Two-Step
Electro-Magnetic
Tappet
Pivot Element
Finger Follower
Shifting Cam
Roller Lifter
Three-Step
Rocker Arm
Shifting Cam
Page 19
Mechanical
e.g. Valvetronic
Electro-Hydraulic
UniAir
Overview of Schaeffler Valve Train Variabilities
Switchable
Tappet
Switchable Pivot
Element
Electro-Hydraulic Actuated
Electro-Mechanical Actuated
(Enlarged Temperature Range)
Profile Switching
Valve Deactivation
(1 Valve per Cylinder)
Cylinder Deactivation
(All Valves per Cylinder)
Internal EGR
(Recharge)
Internal EGR
(Recapture)
Crossing of Valve
Events
2-Step
3-Step
Page 20
Switchable Roller
Finger Follower
Shifting Cam
Lobe
Overview of fully variable Valve Train Variabilities
Mechanical
INA
EcoValve
BMW
Toyota
Valvetronic II Valvematic
Electro-Magnetic
Nissan
Presta
VVEL DeltaValveControl
Suzuki
SNVT
Yamaha
CVVT
Delphi
VVA
Mahle
VLD
Hilite
Univalve
Meta
VVH
Mitsubishi
MIVEC
Honda
A-VTEC
Fiat
3D-CAM
Toyota
3D-CAM
Valeo
E-Valve
FEV
MV2T
Electro-Hydraulic
INA / FIAT
UniAir/
MultiAir
AVL /
Bosch
EHVT
INA
3CAM
= Systems in Mass Production
Page 21
Sturman
HVA
Lotus
AVT
Complete Vehicle Simulation
NEDC
el
u
F
ap n
M
e
in
tio
Eng nsump
Co
Fre
q
Dis uency
trib
utio
n
Engine Map Fuel Consumption
 enhanced models (gas exchange and high pressure process)
Page 22
Evaluation of Potential: Procedure
bar
Basis Motor
NEDC
Downsizing Concept
(turbocharged 4 Cylinder-DI-Engine)
Vehicle Model
Medium-Sized Vehicle
Manual Transmission
min -1 (Speed)
Cylinder 1
Cylinder 2
Cylinder 3
Cylinder 4
2-Step
2-Step
(CDA)
Valve Lift
Evaluation
of Potential
of different
Switching
Stages
3-Step
Optimization
Effort
3-Step
(Cylinder
selective)
Page 23
No Lift
No Lift
Example of Optimization
Fuel Consumption Improvement
relative to Base Version
t in %
20
10.0
9.5
bar
9.0
8.5
8.0
7.5
16
7.0
6.5
6.0
14
5.5
5.0
4.5
BMEP
12
4.0
3.5
3.0
10
2.5
hV= 6,2 - 7,4 mm
2.0
1.5
8
1.0
1.9
6
hV= 4,4 - 4,7 mm
hV= 3,5 mm
0.9
0.8
3.4
0.7
4.8
0.6
0.5
4
6.0
9.9
10.8
2
9.4
9.6 9.3
0.4
0.3
6.5
9.6
0.2
0.1
0.0
0
0
500
1000
1500
2000
Speed
Page 24
2500
min-1
3500
n = 2100 min-1, BMEP = 1,1bar
Valve Lift
90
BMEP
g/kWh
ºCA
°
Exhaust
Gas Rate
Phase of Intake
70
60
50
30
Valve Lift
40
Lowest Consumption
Inlet
Pressure
Crank Angle
20
2
3
4
5
6
Lift of Intake
Page 25
7
mm
9
140
Valve Lift
ºCA
100
Crank Angle
60
40
Exhaust Gas Rate in %
20
Valve Lift
Phase of Intake
80
Crank Angle
0
1
2
3
4
5
6
7
8
mm
10
Valve Lift
Internal EGR (Residual Gas
↑)
▪ Improved Gas Properties
→ Reduction of Proces Temperature
→ Reduction of Energy Losses to Coolant
▪ But: Increase of Combustion Duration
Page 26
140
Valve Lift
ºCA
36
36
100
38
38
Crank Angle
42
42
80
60
44
44
46
46
48
48
50
50
40
Valve Lift
Phase of Intake
40
40
52
52
54
54
20
Combustion Duration in ºCA
0
1
2
3
4
5
6
7
8
mm
Valve Lift
Page 27
10
Crank Angle
140
Valve Lift
ºCA
350
350
100
Crank Angle
80
60
700
700
40
Valve Lift
Phase of Intake
450
450
950
950
20
Inlet Pressure in mbar
Crank Angle
0
1
2
3
4
5
6
7
8
mm
Valve Lift
Page 28
10
Agenda
1
2
3
4
Degree of improvement
Improvement of Conventional Combustion Engines
5
Variable
Valve
Conclusive
Remarks
6
Conclusive Remarks
Page 29
Degree of improvement of Conventional Combustion Engines
2-Step (all Cylinders)
100%
-5,7%
-6%
-10,2%
-11%
3-Step (all Cylinders)
3-Step (Cylinder sel.)
Basis
2-Step
3-Step
NEDC
NEDC
Page 30
2-Step
(CDA)
3-Step
(Cylinder
selective)
Results with customer-specific Drive Profiles
The Hyzem cycles
consist of an urban cycle,
an extra-urban cycle, and
a highway cycle.
Higher dynamics than
NEDC.
Page 31
Degree of improvement of Conventional Combustion Engines
NEDC
100%
-10,2%
-11%
-3,3%
-7,4%
Hyzem
3-Step (Cylinder sel.)
Basis
3-Step
2-Step (CDA) (Cylinder
selective)
NEDC
NEDC
Page 32
2-Step
(CDA)
3-Step
(Cylinder
selective)
Hyzem
Hyzem
Potential for Consumption Improvements
Friction Improvements
Thermodynamic Improvements
<3%
Diesel
<7%
Gasoline
4-6%
Friction Reduction
2-3%
Demand Controlled
Accessories
Further Improvements
1-2%
Thermo-Management
5-8%
Downsizing
3-5%
Stop-Start Function
Combustion System
Optimization
Pumping Losses
Gasoline
Page 33
2-3%
Agenda
1
2
3
4
5
Variable
Valve
Conclusive
Remarks
6
Conclusive Remarks
Page 34
Principle of Sequential Turbocharging
Conventional 2-Stage T/C
With Split Exhaust Ports
Exhaust Port Group 1
Intercooler
Exhaust Port Group 2
Intercooler
Control
Valve
Bypass
Valve
Bypass
Valve
WG 1
High Press. T/C
WG 1
High Press. T/C
WG 2
WG 2
Bypass
Valve
Low Press. T/C
Bypass
Valve
Page 35
Low Press. T/C
Activation of Ports for Sequential Turbocharging
EPG 1 Activ
EPG 2 Activ
EPG 1
EPG 1+2 Activ
EPG 1
EPG 1
EPG 2
EPG 2
Page 36
EPG 2
BMEP
Sequential Activation of Exhaust Ports
EPG 2
EPG 1
Engine Speed
Page 37
BMEP
Sequential Activation of Exhaust Ports
EPG 1+2
EPG 2
EPG 1
Engine Speed
Page 38
Exhaust Valve Opening
Lower Engine Speed
10
Valve Lift [mm]
Exhaust Valve Group 1
8
Short event, low lift
Exhaust gas removal from cylinder,
6
Loading of primary T/C
4
Exhaust Valve Group 2
2
Late phasing, variable lift and event
EGR scavenging, loading secondary
T/C
0
0
90
180
270
360
450
540
630
720
Crank Angle
Page 39
Exhaust Valve Opening
Middle to High engine Speed
10
Exhaust Valve Group 1+2
Valve Lift [mm]
8
Similar to basis engine
Exhaust gas removal from cylinder,
Loading of both T/C
6
4
2
0
0
90
180
270
360
450
540
630
720
Crank Angle
Page 40
Benefits of Sequential Turbocharging
21
BMEP [bar]
19
17
Basis engine with T/C
Conventional sequential T/C
Sequential T/C with splited ports
15
13
11
1000
2000
3000
4000
5000
6000
Engine Speed [rpm]
Significant increase of Low-End-Torque compared to turbocharged basis
engine (smaler turbine).
Additional Low-End-Torque enhancement (compare green and blue), due to
better exhaust gas scavenging and lower enthalpy.
Page 41
Agenda
1
2
3
4
5
6
Conclusive Remarks
Page 42
Conclusions
Conclusive Remarks
Nobody
Nobody knows
knows exactly
exactly what
what the
the powertrain
powertrain world
world will
will really
really look
look like
like in
in
2020
2020 and
and beyond
beyond
But:
But: The
The potential
potential for
for further
further innovations,
innovations, and
and the
the associated
associated opportunities
opportunities
for
for reducing
reducing CO2
CO2 emissions
emissions are
are highly
highly promising
promising and
and far
far from
from beeing
beeing
exhausted
exhausted
Variable
Variable valve
valve train
train technology
technology is
is aa key
key element
element in
in realizing
realizing further
further
improvements
improvements
Variable
Variable valve
valve train
train leverages
leverages other
other ICE
ICE technologies
technologies like:
like: turbocharging,
turbocharging,
cylinder
cylinder deactivation,
deactivation, aftertreatment,
aftertreatment, etc.
etc.
Drive
Drive cycle
cycle and
and drive
drive train
train layout
layout need
need to
to be
be included
included to
to come
come to
to aa final
final
evaluation
evaluation
The
The assessment
assessment of
of improvement
improvement potential
potential also
also need
need to
to consider
consider the
the
impact
impact and
and aspects
aspects of
of the
the monitoring
monitoring and
and control
control technology
technology
Page 43
Eduard Golovatai-Schmidt
Research & Development, Engine Systems Division
Schaeffler AG, Herzogenaurach
Page 44
VVA and Turbochargers: possible synergies for Gazoline engines?
Stéphane GUILAIN
Technical Expert in PWT Aerodynamics and Engine Air Filling
VVA Workshop – 2013 April 18th
DIM
DCT – DESV (SGN)
April 18th 2013
RENAULT PROPERTY
Plan
DIM
DCT – DESV (SGN)
1 Introduction
Looking for PMEP reduction through
2 VVA or Turbo ?
VVA & Turbo: improving the scavenging
3 at low engine speed with 4 cylinder engines
VVA & Turbo: improving the scavenging
4 at low engine speed with 3 cylinder engines
5 Conclusions
April 18th 2013
RENAULT PROPERTY
1 Introduction
DIM
DCT – DESV (SGN)
April 18th 2013
RENAULT PROPERTY
PLAN
1 Introduction
Need of Fuel Consumption decrease

CAFE Targets require optimization of all components
2 VVA/Turbo
& PMEP
3 VVA/Turbo
& Scavenging
with 4 cyl.
4 VVA/Turbo
& Scavenging
with 3 cyl.
5 Conclusion
DIM
DCT – DCFM (SGN)
April 18th 2013
CONFIDENTIAL
RENAULT PROPERTY
4
PLAN
1 Introduction
2 VVA/Turbo
& PMEP
Need of Fuel Consumption decrease
 FE to CO2 gap have to be kept under control for customers
Outrage: How manufacturers are fiddling. The Fuel Economy Lie
Motor Press Evaluates Real World Fuel Efficiency
3 VVA/Turbo
& Scavenging
with 4 cyl.
4 VVA/Turbo
& Scavenging
with 3 cyl.
5 Conclusion
Comparison Road Distribution
[% km]
37
d
cheate
23 26
d
palliate
Urban
40 39
Rural
NEDC
t
hones
DIM
DCT – DCFM (SGN)
April 18th 2013
CONFIDENTIAL
RENAULT PROPERTY
MBVT
Autobild
5
37
77 74
63
35
Highway
Extra-Urba
(Rural+Highw
Source: Autobild 05.09.200
PLAN
1 Introduction
2 VVA/Turbo
& PMEP
Turbocharged Gazoline Engine and
Fuel consumption improvement
Torque
5
250
3 VVA/Turbo
& Scavenging
with 4 cyl.
3
4
4 VVA/Turbo
& Scavenging
with 3 cyl.
27
1
280
PME [bar]
5 Conclusion
249
2
Colors = BSFC Levels
0
1000
1500
2000
2500
3000
3500
4000
4500
N [rpm]
DIM
DCT – DCFM (SGN)
April 18th 2013
CONFIDENTIAL
RENAULT PROPERTY
6
5000
Engine
5500 speed
PLAN
1 Introduction
VVA and turbocharger contributions on BSFC Map
2 VVA/Turbo
& PMEP
3 VVA/Turbo
& Scavenging
with 4 cyl.
4 VVA/Turbo
& Scavenging
with 3 cyl.
5 Conclusion
DIM
DCT – DCFM (SGN)
April 18th 2013
CONFIDENTIAL
RENAULT PROPERTY
7
PLAN
1 Introduction
Illustration of VVA and turbocharger contributions
2 VVA/Turbo
& PMEP
3 VVA/Turbo
& Scavenging
with 4 cyl.
TCE 115
4 VVA/Turbo
& Scavenging
with 3 cyl.
4
cyl engine / 16 valves
TCE 90
3
cyl engine / 12 valves
5 Conclusion
1.2
0.9
L
Bore
x Stroke : 72.2 /73.1
Compression
DIM
DCT – DCFM (SGN)
Ratio : 9.5 :1
L
Bore
Compression
GDI
MPI
2
1
VVT
April 18th 2013
x Stroke : 72.2 x 73.1
CONFIDENTIAL
RENAULT PROPERTY
intake VVT
8
Ratio : 9.5 :1
2
DIM
DCT – DESV (SGN)
Looking for PMEP reduction through
VVA ou Turbo ?
April 18th 2013
RENAULT PROPERTY
PLAN
1 Introduction
VVA + open wastegate in partial load

Interest to open the wastegate in NA region
2 VVA/Turbo
& PMEP
3 VVA/Turbo
& Scavenging
with 4 cyl.
4 VVA/Turbo
& Scavenging
with 3 cyl.
5 Conclusion
BSFC reduction in partial load
(VVA/turbo)
thanks pumping losses reduction
DIM
DCT – DCFM (SGN)
April 18th 2013
CONFIDENTIAL
RENAULT PROPERTY
10
PLAN
1 Introduction
VVA + opened wastegate at partial load

The drawback : Turbo speed
2 VVA/Turbo
& PMEP
3 VVA/Turbo
& Scavenging
with 4 cyl.
4 VVA/Turbo
& Scavenging
with 3 cyl.
5 Conclusion
Every time, PMEP and BSFC are improved thanks
turbocharger or VVA.
The turbo speed is reduced
DIM
DCT – DCFM (SGN)
April 18th 2013
CONFIDENTIAL
RENAULT PROPERTY
11
PLAN
1 Introduction
VVA + opened wastegate at partial load

A drawback: the transient behavior
2 VVA/Turbo
& PMEP
3 VVA/Turbo
& Scavenging
with 4 cyl.
4 VVA/Turbo
& Scavenging
with 3 cyl.
5 Conclusion
BSFC reduction in partial load
( for instance VVA/turbo)
and transient improvement
are opposite
=> Need to promote countermeasures to help the transients
at low end speed
DIM
DCT – DCFM (SGN)
April 18th 2013
CONFIDENTIAL
RENAULT PROPERTY
12
3
DIM
DCT – DESV (SGN)
VVA & Turbo : improving the scavenging
at low end speed with 4 cylinder engines
April 18th 2013
RENAULT PROPERTY
PLAN
1 Introduction
VVA/Turbo and 4 cylinder engines

2 VVA/Turbo
& PMEP
4 cylinder issue: scavenging period closed to exhaust
blowdown
5500 rpm
1500 rpm
3 VVA/Turbo
& Scavenging
with 4 cyl.
4 VVA/Turbo
& Scavenging
with 3 cyl.
5 Conclusion
Pint < Pcyl< Pexh
Exhaust.
TDC
Intake.
Intake
Air + Burnt gas
With no VVT, due to the fixed
timing imposed by idle conditions,
savenging is impossible
Exhaust valve duration is shorten
to reduce the backflow during
overlap period
BDC
DIM
DCT – DCFM (SGN)
April 18th 2013
CONFIDENTIAL
RENAULT PROPERTY
14
PLAN
1 Introduction

2 VVA/Turbo
& PMEP
The 4 cylinder issue: Interest to have VVTs at low engine
speeds
1500 rpm
3 VVA/Turbo
& Scavenging
with 4 cyl.
4 VVA/Turbo
& Scavenging
with 3 cyl.
5 Conclusion
Pint > Pcyl> Pexh
Exhaust.
TDC
Intake.
Intake
Air + Burnt gas
BDC
DIM
DCT – DCFM (SGN)
April 18th 2013
CONFIDENTIAL
RENAULT PROPERTY
15
Late EVO
=> scavenging
is possible
PLAN
1 Introduction

Solving 4 cylinder issue: using VVTs at low engine speeds
1500 rpm
2 VVA/Turbo
& PMEP
3 VVA/Turbo
& Scavenging
with 4 cyl.
4 VVA/Turbo
& Scavenging
with 3 cyl.
5 Conclusion
Pint > Pcyl> Pexh
Exhaust.
TDC
Intake.
Intake
Air + Burnt gas
BDC
DIM
DCT – DCFM (SGN)
April 18th 2013
CONFIDENTIAL
RENAULT PROPERTY
16
even late EVO
=> scavenging
is reinforced
PLAN
1 Introduction

Solving 4 cylinder issue: using VVTs at low engine speeds
2 VVA/Turbo
& PMEP
3 VVA/Turbo
& Scavenging
with 4 cyl.
4 VVA/Turbo
& Scavenging
with 3 cyl.
5 Conclusion
Thanks to the increase of The
plenum volumetric efficiency, boost
pressure is enhanced.
Torque at 1000 rpm can be
improved up to 20 %
DIM
DCT – DCFM (SGN)
April 18th 2013
CONFIDENTIAL
RENAULT PROPERTY
17
PLAN
1 Introduction

2 VVA/Turbo
& PMEP
Solving 4 cylinder issue: increasing the scavenging potential
through exhaust manifold
3 VVA/Turbo
& Scavenging
with 4 cyl.
4 VVA/Turbo
& Scavenging
with 3 cyl.
5 Conclusion
Twinscroll
Separation wall
Twinscroll turbine housing allow to
separate consecutive cylinders.
An issue: casting thin walls of
twinscroll housing for small engines
DIM
DCT – DCFM (SGN)
April 18th 2013
CONFIDENTIAL
RENAULT PROPERTY
An emerging alternative:
Having the separation only
within the manifold
18
PLAN
1 Introduction

3 VVA/Turbo
& Scavenging
with 4 cyl.
4 VVA/Turbo
& Scavenging
with 3 cyl.
without
2 VVA/Turbo
& PMEP
Solving 4 cylinder issue: Effect of separation wall in turbine
housing
5500 rpm
1500 rpm
with
5 Conclusion
A synergy of 2-4 % of torque can be promoted
between 1000 to 1750 rpm and better transient
DIM
DCT – DCFM (SGN)
April 18th 2013
CONFIDENTIAL
RENAULT PROPERTY
19
PLAN
1 Introduction

2 VVA/Turbo
& PMEP
VVT + Turbo in transient.
1500 rpm
3 VVA/Turbo
& Scavenging
with 4 cyl.
Huge synergy between
VVts and turbochargers
through the scavenging
process.
4 VVA/Turbo
& Scavenging
with 3 cyl.
Turbocharger behavior
is transformed.
5 Conclusion
A difficulty :
Knowing accuratly the
trapped air mass to
adapt injection duration
DIM
DCT – DCFM (SGN)
April 18th 2013
CONFIDENTIAL
RENAULT PROPERTY
20
4
DIM
DCT – DESV (SGN)
VVA & Turbo : improving the scavenging
at low end speed with 3 cylinder engines
April 18th 2013
RENAULT PROPERTY
PLAN
1 Introduction

2 VVA/Turbo
& PMEP
3 cylinder engines: natural favourable situation
1500 rpm
3 VVA/Turbo
& Scavenging
with 4 cyl.
4 VVA/Turbo
& Scavenging
with 3 cyl.
5 Conclusion
Pint > Pcyl> Pexh
Exhaust.
TDC
Intake.
Intake
Air + Burnt gas
Scavenging is
natural with 3
cylinder engine
BDC
DIM
DCT – DCFM (SGN)
April 18th 2013
CONFIDENTIAL
RENAULT PROPERTY
22
PLAN
1 Introduction
2 VVA/Turbo
& PMEP

3 cylinder engines: natural favourable situation
5500 rpm
3 VVA/Turbo
& Scavenging
with 4 cyl.
4 VVA/Turbo
& Scavenging
with 3 cyl.
5 Conclusion
Pint > Pcyl> Pexh
Exhaust.
TDC
Intake.
Intake
Air + Burnt gas
BDC
DIM
DCT – DCFM (SGN)
April 18th 2013
CONFIDENTIAL
RENAULT PROPERTY
23
Due to the
shape of the
pulsations,
we are close to
scavenge at
max power
PLAN
1 Introduction

In transient
2 VVA/Turbo
& PMEP
Huge synergy between
VVts and turbochargers
through the scavenging
process.
3 VVA/Turbo
& Scavenging
with 4 cyl.
4 VVA/Turbo
& Scavenging
with 3 cyl.
Turbocharger behavior
is also transformed.
5 Conclusion
Same difficulty:
knowing the trapped
mass flow rate and thus
the trapped in-cylinder
Air/fuel ratio
DIM
DCT – DCFM (SGN)
April 18th 2013
CONFIDENTIAL
RENAULT PROPERTY
24
PLAN
1 Introduction

Scavenging and MPI engine: take care to emissions and BSFC
2 VVA/Turbo
& PMEP
3 VVA/Turbo
& Scavenging
with 4 cyl.
4 VVA/Turbo
& Scavenging
with 3 cyl.
5 Conclusion
With MPI engine, fuel is
included within the scavenged
air and goes directly to the
exhaust
VVT Actuation have to be
limited in time
DIM
DCT – DCFM (SGN)
April 18th 2013
CONFIDENTIAL
RENAULT PROPERTY
25
5 Conclusion
DIM
DCT – DESV (SGN)
April 18th 2013
RENAULT PROPERTY
PLAN
1 Introduction
Conclusion

2 VVA/Turbo
& PMEP
Huge synergies between turbo and VVTs
Torque
250
3 VVA/Turbo
& Scavenging
with 4 cyl.
4
4 VVA/Turbo
& Scavenging
with 3 cyl.
280
PME [bar]
5 Conclusion
249
The scavenging have to be
promoted
Natural with 3 cyl engines
Some limitations with MPI
engines
Limitations
with the
transient
behavior
Big
potential
in steady
state
2
Colors = BSFC Levels
0
1000
1500
2000
2500
3000
3500
4000
4500
N [rpm]
DIM
DCT – DCFM (SGN)
April 18th 2013
27
CONFIDENTIAL
RENAULT PROPERTY
27
5000
Engine
5500 speed
PLAN
1 Introduction
Conclusion

2 VVA/Turbo
& PMEP
Optimal setting for full VVA System at full load
Engine
Engine
3 cylinder
4 cylinder
speed
speed
3 VVA/Turbo
& Scavenging
with 4 cyl.
4 VVA/Turbo
& Scavenging
with 3 cyl.
5 Conclusion
Exhaust
Intake
Exhaust
Crank
angle
DIM
DCT – DCFM (SGN)
April 18th 2013
CONFIDENTIAL
RENAULT PROPERTY
Intake
Crank
angle
28
PLAN
1 Introduction
Conclusion

Perspectives of future researches
2 VVA/Turbo
& PMEP

Potential improvement of steady state BSFC and transient
behavior
3 VVA/Turbo
& Scavenging
with 4 cyl.

Wall separation of turbine housing of 4 cylinder engines

Trapped Air & fuel mass estimation under transient
conditions
4 VVA/Turbo
& Scavenging
with 3 cyl.
5 Conclusion
DIM
DCT – DCFM (SGN)
April 18th 2013
CONFIDENTIAL
RENAULT PROPERTY
29
TRENDS IN APPLICATION OF VVA SYSTEMS
FOR FUEL EFFICIENT POWERTRAIN
Presentation for
University of Pitesti
VVA Workshop
Pitesti, 18th April 2013
Dr. Hubert FRIEDL
Product Manager
Powertrain Engineering
AVL List GmbH, Austria
INTRODUCING AVL
AVL is the world’s largest
private and independent
engineering company
Development of powertrain
systems with internal
combustion engines
Software for engine and
vehicle simulation
Prof.
Prof. Helmut
Helmut List
List
Owner
Owner and
and CEO
CEO
Pitesti-VVT Workshop, H. Friedl, 2013
Instrumentation and test
systems for engine and
vehicle development
2
AVL COVERS ALL CUSTOMER SEGMENTS
Engineering
Passenger Cars
2-Wheelers
Racing
Simulation
Construction
Agriculture
Commercial Vehicle
Testing
Locomotive
Marine
Power Plants
3
AVL – TECHNICAL CENTERS POWERTRAIN
Ann Arbor,MI
Haninge
UK
Sweden
Södertalje
Headquarters Graz
Moscow
Plymouth, MI
Tokio
Nagoya
Lake Forest, CA
Korea
China
Sao Paulo
Germany
France
Munich
Regensburg
Stuttgart
Ingolstadt
India
Remscheid
Turkey
Australia
5
Presentation for
University of Pitesti
VVA Workshop
Pitesti, 18th April 2013
Dr. Hubert FRIEDL
Product Manager
Powertrain Engineering
AVL List GmbH, Austria
Content of Presentation:
1. Market Trends
•Global PC Production Survey
•VVA Market Penetration
2. Challenges due to Forthcoming Regulations
•CO2 Reduction
•Legislation and Test Procedures (WLTP, RDE)
3. Technology - Examples of VVA Applications
•Cam Phaser: CBR, Cylinder Deactivation
•Profile switching: TGDI - Turbocharged GDI
•Variable Valve Lift: CSI - Compression and Spark Ignition
4. Summary and Outlook
8
GLOBAL ENGINE PRODUCTION BY REGION
(PC and LCV, Status 10-2012)
ROW
REST OF ASIA
SOUTH KOREA
JAPAN
INDIA
CHINA
SOUTH AMERICA
NORTH AMERICA
WEST EUROPE
EAST EUROPE
 Ca. 20% drop in engine production by 2009
 2011 significant impact due to Japan downtime
 2013 moderate growth expectation EU, US and Asia
 China maintain strongest growth regions
100
90
Mio. units produced
80
70
Asia
60
50
40
America
30
20
Europe
10
1995
2000
2005
Source: IHS 10/2012
2010
2015
9
GLOBAL ENGINE PRODUCTION BY PROPULSION
TECHNOLOGY (PC and LCV, Status 10-2012)
ALCOHOL FUEL
GASOLINE GDI
GASOLINE PFI
GASOLINE charged
DIESEL CHARGED
DIESEL NA
CNG/LPG
Full HYBRID
ELECTRIC
 Market penetration for new propulsion technologies
(e.g. Hybrid, Electro Vehicles) usually is slow (>10 years)
100
90
Diesel
Mio. units produced
80
70
GDI
60
50
40
30
20
10
1995
Gasoline
Significant Technology Evolution:
 Strong growth of GDI direct injection and
Turbocharging expected for gasoline engines
 CNG, E100, Hybrid and EV forecasted to globally
grow stronger than PC-Diesel
2000
2005
Source: IHS 10/2012
charged
2010
2015
10
GLOBAL VEHICLE PRODUCTION PER REGION
AND BY PROPULSION TECHNOLOGY
100
Diesel
H2/Electric
90
Full Hybrid
80
E100
70
E85
Gasoline
60
50
40
30
20
Source: IHS 10-2012
11
2019
2012
Global 2007
2019
2012
S. ASIA + ROW 2007
2019
2012
S. AMERICA 2007
2019
2012
2019
2012
JAPAN/KOREA 2007
Region/Year
CHINA 2007
2019
2012
NAFTA 2007
2019
2012
10
EUROPE 2007
Engines Produced
 Europe: Future growth expected in SI and alternative technologies
 NAFTA: Growth expected for Hybrids and Flex Fuel
 China: Growth forecasted mainly with conventional technology
 Japan/Korea: growth with Hybrids, shrinking (local) production
CNG/LPG
VALVETRAIN TECHNOLOGY SHARES FOR
GASOLINE PASSENGER CARS BUILT IN EUROPE
SI Engines without VVT/VVL
Million
14
Source: IHS 2013
Valve Lifting only
Cam Changing only
Cam Phasing only
12
Cam Phasing/Valve Lifting
Cam Phasing/Cam Changing
10
8
6
4
2
0
2011
2012
2013
2014
2015
2016
2017
2018
2019
12
Million
VALVETRAIN TECHNOLOGY SHARES FOR
GASOLINE PASSENGER CARS BUILT IN JAPAN
SI Engines without VVT/VVL
12
Source: IHS 2013
Valve Lifting only
Cam Changing only
10
Cam Phasing only
Cam Phasing/Valve Lifting
Cam Phasing/Cam Changing
8
6
4
2
0
2011
2012
2013
2014
2015
2016
2017
2018
2019
13
1. Market Trends
•CO2 Reduction
15
DEPLOYMENT OF VEHICLE CO2-AVERAGE IN EUROPE
240
CO2 in NEDC (g/km)
220
CO2 Fleet Average in Europe
Fleet average improvement strongly affected by
scrapping bonus 2009 (focus on smaller cars)
 still far distance to 2020 targets
Gasoline
Diesel
200
All Fuels
180
160
137 g/km
140
CO2 Target for 2015
120
CO2 Target for 2020
100
80
1990
Source: EEA Report, Monitoring CO2 emissions from new passenger cars in the EU; summary of data for 2011, published 2012
1995
2000
2005
2010
2015
2020
16
MARKET DISTRIBUTION OF VEHICLE SEGMENT GROUPS
AND SHARE OF DIESEL - EUROPE
Diesel
Source: IHS and AutomotiveWorld 2011
17
CO2 EMISSION OF PASSENGER CARS VERSUS
VEHICLE WEIGHT AND PROPOSED CO2 LIMITS
450
Gasoline NA
400
CO2 Emission in NEDC [g/km]
Diesel
350
Gasoline Turbo
300
Gasoline Hybrid
250
CNG Turbo
200
150
China Stage 3
revised - CO2 [g/km]
100
EU-proposed CO2
Limit
50
0
500
1000
1500
Vehicle Curb Weight [kg]
2000
2500
Source: AR 2012
18
Light Duty Emission Legislation
EU Limits
Emission
CO
Compression HC + NOx
Ignition
NOx
Engines
PM
(Diesel)
PN
mg/km
CO
HC
HC + NOx
NOx
NMHC
PM only GDI
PN
mg/km
Positive
Ignition
Engines
(Gasoline)
mg/km
EU-1
1992
EU-2
1996
EU-3
2000
EU-4
2005
2720
970
1000
700
140
80
640
560
500
50
500
300
250
25
500
230
180
5
2720
2200
2300
200
1000
100
1000
100
1000
100
1000
100
970
500
150
80
60
68
5
60
68
4.5
60
68
4.5
6E12
mg/km
mg/km
#/km
mg/km
mg/km
mg/km
mg/km
mg/km
#/km
Moderate Reduction (<30%)
•
EU-5 EU-5+ EU-6
2009 2011 2014
500
500
230
170
180
80
4.5
4.5
6E11 6E11
Large Reduction (>30%)
The main challenge for Gasoline Engine with EU6 is not the nominal limit of Gaseous Emissions,
but the significantly more strict Diagnostic Requirements, PN limit 6E11 by 2018 for all PC
19
PC Emission Legislation - Expected Changes
2013
2014
2015
2016
2017
2018
2019
2020
EU 6c
EU 6b
2022
2023
EU 7
NEDC (Emissions)
NEDC (CO2)
2021
WLTP (Emissions)
WLTP (CO2)
RDE (monitoring)
RDE (compl. factors open)
RDE (stringent compl. factors)
PFI: no limit
DI: 6*1011 /km (6*1012 on dem.)
CI: 6*1011 /km
CI, DI: 6*1011 /km
130 g/km (or adapted to WLTP)
adopted
discussed, no proposal available
adopted proposal
rumors
tbd (WLTP); mod. procedure?
95 g/km (or adapted to WLTP)
Source: 110. MVEG, ACEA: Summary of Euro 6 open issues, 25.10.2011,
http://ec.europa.eu/clima/policies/transport/vehicles/index_en.htm,
Commission Regulation: No 459/2012 of 29.5.2012, 6th EU-WLTP Meeting ,
EUROPEAN COMMISSION: Possible scenarios of implementation WLTC
into European type approval legislation, 10.04.2012 20
PC Emission Legislation – Type Approval
or
WLTP
PEMS
RTC
(world light duty test
procedure)
(portable emission
measurement)
(random test cycles)
acceleration m/s2
mean velocity km/h
idle share %
WLTP
1.8
46
13
NEDC
1.0
33
23
•driven by EC
•on board measurement
•real on-road driving
•real temp. condition
•curr. no PN measurement
•possibly HC excluded
•driven by OEMs on their
cost
•OEMs need to prove similar
results as PEMS
•tested at chassis dyno
•random based on EU
database (20.000 trips)
22
Md - Nm
Load Collective NEDC vs. RDE
RandomTest
Prio 2
Options for RDE:
Random Test
Prio 1
PEMS: all modes possible
•Random test cycle:
Chassis Dyno
Simulation
•PEMS:
Measurement in
customer driving with
PEMS
NEDC
 Decision open
N - upm
23
1. Market Trends
•CO2 Reduction
25
TECHNOLOGIES AND POTENTIALS FOR EFFICIENCY
IMPROVEMENT OF PASSENGER CARS
Hybrid-Drives,
Electrification
Friction Optimization
Start/Stop
Navigation
Aerodynamics
Low Friction
Lube Oil
Weight
Fuel
Intelligent Alternator Control
Tires
Downsizing and
Turbocharging
Dual Clutch,
Automatic Transm.
Fully variable
Valvetrain
Braking Energy
Recuperation
Electrified
Auxiliary Drives
Direct Injection
and Lean Mixture
Air Conditioning
Photo Source: Esso Exxon
Thermal-Management,
Heat Recovery
26
GASOLINE ENGINE TECHNOLOGY
Cylinder Dectivation
-Mechanical
-Electronical
Boosting
-2-stage
-electric boosting
-water cooled VGT
Variable Valvetrain
-2-step / 3-step
-fully flexible
Combustion System
-high BMEP TGDI
-Low PN
-CNG-DI
2-step
low lift
Exhaust Gas Cooling
- External cooled EGR
- Cooled / integrated
manifold
2-step
high lift
3-step
l/h lift
cont.
Variable Crank Train
-Var. Compression ratio
-Var. Expansion ratio
“Smart Hybridization”
-electric auxiliaries
-48V systems
27
Future Gasoline Engine
Cam phasing, CDA
GDI homogeneous
Current
Main stream
Premium
Niche appl.
Turbocharging
Micro hybrid
High charge motion
Cooled EGR, cooled exhaust
Variable valvetrain (Miller, Atkinson)
GDI stratified lean
Means to increase EGR rate
Var. compression ratio, var. expansion
Alt. combustion (HCCI, qual. control)
Mild hybrid
Full hybrid
Plug-in hybrid (certification!?)
E-vehicle; range extender
Time
28
Overview Variable Valve Timing/Lift/Duration
Variable Valve Actuation can be segmented into Variable Valve Timing
(Phasing) as well as variating the Valve Lift and Opening Duration
Fully-variable lift curve
Valve lift
Variable valve lift
Valve lift
Valve lift
Variable cam-phasing
Crank angle
Crank angle
Crank angle
Variable Charge Motion,
Charged GDI
Controlled Auto Ignition
29
1. Market Trends
•CO2 Reduction
30
VARIABLE CHARGE MOTION SYSTEM
PATENTED AS AVL - CONTROLLED BURN RATE
CBR 1
External
EGR Feed
Port deactivation
by slider or
butterfly valve
Twin spray injector
on
-o
ff
Tangentialport
Neutral port
CBR 2
Internal EGR
Feed by means
of Cam Phaser
swirl
Neutral
Tangential
very stable
combustion
andport
tolerance forport
high EGR-rates
enable low fuel consumption
31
VARIABLE CHARGE MOTION SYSTEMS
- Examples of Series Applications
CBR 1
CBR 2
Source: FIAT
Source : Opel
32
Evolution of AVL´s CBR - Technology by “Intelligent
Simplification”
CBR 1
n
n
n
n
n
n
n
Spec. port design
1 EGR Valve
1 EGR-Distrib. System
4 Flaps
4 Axles + Levers
1 Connecting System
1 Actuator (on-off)
CBR 2
n
n
n
n
n
Spec. port design
1 (2) Cam Phaser
1 Low Cost Slider
1 Lever
1 Actuator (on-off)
CBR 3
n
n
n
Spec. port design
1 (2) Cam Phaser
Exh. valve masking
Internal EGR Feed by means of Cam Phaser
33
APPLYING LATE ATKINSON CYCLE WITH AVL CBR II SYSTEM
Shift of Intake and Exhaust Camshaft, Open Valve Injection
Part Load Operation
Exh. Cam
EGR
Int. Cam
Int. Cam
Aspiration
Exh. Cam
Backflow
Valve Lift
(mm)
Valve
Lift
(mm)
10
High Load
9
Exhaust
8
Intake
7
Low Load
Exhaust
6
Intake
5
4
3
2
1
0
120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 440 460 480 500 520 540 560 580 600 620 640
Crank Position (deg. CrA )
Crankshaft
Position (deg.CrA)
Injection Timing at High Load
Injection Timing at Low Load (Stratification at BDC)
34
The Principle of 2-Valve CBR –
Impact of Valve Masking for Swirl Generation
Intake Swirl
Exhaust Port
(with Masking)
2-Valve CBR System
successfully in series
application since many years
irection
Main Flow D
 High charge motion is
enabler for high EGR-rates
 intake dethrottling for
low pumping losses
Exhaust Swirl
Spark Plug
Intake
(Tangential Port)
35
CONTROLLED BURN RATE III - CBR 3rd Generation
Features of CBR III for 2- and 4-Valve Engines:
• No port deactivation
• Internal EGR and Atkinson Cycle by cam phase shifter(s)
• Swirl/Tumble generation by tangential intake and exhaust ports
• Swirl/Tumble enhanced with masking and asymetric exhaust valve
lift with 4-valve engines
Fuel economy improvement: approx. 3 - 5 %
Good example of „Intelligent Simplicity“
36
CYLINDER DEACTIVATION
(Valves fully closed, piston and cylinder act as spring)
Honda V6 Odyssey (USA)
VW Golf/Polo 1.4 TSI
Potential for FC Improvement
for Cylinder Deactivation:
•transient operation: up to 7%
•constant speed: up to 20%
strongly depending on engine size and
NVH restrictions
37
AVL´s ELECTRONIC CYLINDER DEACTIVATION
PRINCIPLE OF WORK FOR V6-ENGINE
Mind:
purely electronic
no mech. valve
closing devices
×
×
×
Left Cylinder Bank:
Cam timing for minimum
fuel consumption
ti = 2 x ti average
+ friction
Right Cylinder Bank:
Cam timing for minimum
pumping losses
ti = 0
Intake and Exhaust Valve Lift Curves
8
8
7
7
6
6
Valve Lift [mm]
Valve Lift [mm]
Intake and Exhaust Valve Lift Curves
5
4
3
5
4
3
2
2
1
1
0
0
120
160
200
240
280
320
360
400
440
480
520
560
Crank Shaft Position [°CRA]
600
640
680
120
160
200
240
280
320
360
400
440
480
520
560
600
640
680
Crank Shaft Position [°CRA]
AVL patent application
Gas exchange TDC
Gas exchange TDC
38
“4=2” – Cost Effective Electronic Cylinder Deactivation
for 4-Cylinder Engines
Cylinder deactivation just by
fuel cut off
Exhaust system with complete flow
seperation up to catalyst
Cylinder group 1
ti = 0
Air Exhaust
Cylinder group 2
ti = 2 x ti - be
Separating
wall
Sealing mat
placed in groove
Single brick
catalyst
AVL patent application
39
Electronic Cylinder Deactivation:
4 Cylinder; Fuel Consumption Optimisation
1010
88
66
5
44
660
3
22
1
Engine uses single cam phaser;
intake and exhaust valves can be
retarded parallel.
In part load both valves are operated
in retarded position (low pumping
losses and internal EGR)
BSFC - g/kWh
0 0 40 80 120 160 200 240 280 320 360 400 440 480 520 560 600 640 680
40 120 200 280Crank360
440 520 600 680
Position [°CrA]
Crank Position - °CrA
4 cyl; 2000/1; BSFC
25% residual gas
ECDA;2000/1; BSFC
tolerance limit for 4 cyl.
4 cyl; 2000/1; RG
40
ECDA; 2000/1; RG
640
35
620
30
600
25
580
20
560
15
540
10
520
5
500
350
0
360
370
380
390
400
410
420
Overlap Position - °aTDC
40
Residual Gas Content - %
7
Valve Lift [mm]
Valve Lift - mm
9
Electronic Cylinder Deactivation:
4 Cylinder; Fuel Consumption Optimisation
1010
7
66
5
44
660
22
1
Engine uses single cam phaser;
intake and exhaust valves can be
retarded parallel.
In part load both valves are operated
in retarded position (low pumping
losses and internal EGR)
BSFC - g/kWh
0 0 40 80 120 160 200 240 280 320 360 400 440 480 520 560 600 640 680
40 120 200 280Crank360
440 520 600 680
Position [°CrA]
Crank Position - °CrA
Residual gas tolerance
limit outside operating
area for 2 cyl.
40
640
35
620
30
600
25
580
20
10% benefit
3
4 cyl; 2000/1; BSFC
ECDA;2000/1; BSFC
4 cyl; 2000/1; RG
ECDA; 2000/1; RG
560
540
15
10
520
5
500
350
0
360
370
380
390
400
410
420
Overlap Position - °aTDC
41
Residual Gas Content - %
88
Valve Lift [mm]
Valve Lift - mm
9
120
80
40
0
900
800
700
600
500
400
300
200
100
0
0
100
200
300
400
500
600 700
Time - s
800
900
900
800
700
600
500
400
300
200
100
0
1000 1100 1200
T in Pre Cat - °C
T before Cat - °C
Bank 2
Bank 1
Vehicle Speed – km/h
Electronic Cylinder Deactivation: Toggling = Switching
between the 2 Cylinder Banks to maintain Catalyst active
Temperature in Cat
controlled above 400°C
POWERFUL – Low Consumption Demo Vehicle
Exhaust (Masking)
1,4l 4 cyl. 2 valve
0,9l 2 cyl. 4 valve
180
Intake
(Tangential
140
Port)
1010
9
88
2 cyl is better with MT
Exhaust Swirl
160
Spark Plug
Equal FC with AMT!
120
100
7
Valve Lift [mm]
6 6 80
5
4 4 60
1
0 0 40 20
80 120 160 200 240 280 320 360 400 440 480 520 560 600 640 680
40 120 200 280Crank360
440 520 600 680
Position [°CrA]
Crank
Position
°CrA
0
Clutch Actuator and Control Unit
MT
3
2 2 40
MT
Var. Oil Pump
Intake Swirl
Valve
- mm
CO2Lift
Emission
- g/km
Fiat Punto EVO
FIRE 2V CBR III Engine
Electronic Cylinder
Deactivation
Friction Reduction
Electric Supercharging
Robotised Gearbox with
long gear ratios
Drag Reduction
< 100 g/km CO2
Gear
Actuator
Underbody Cover
DLC Shimless Tappets
700
600
Force - N
500
E- Supercharger
Clutch
Marelli Production AMT
400
y = 0.025x2 + 0.6923x + 93.949
300
Gearshift
Lever
200
Measured Coast Down
Target Coast Down
Original Coast Down
100
Poly. (Measured Coast Down)
Project N° SCP8-GA-2009-234032
0
0
50
100
Vehicle Speed - km/h
150
43
1. Market Trends
•CO2 Reduction
44
Switchable valve lift systems including Cylinder deactivation
Switchable Valve Lift systems in production
Porsche
Volvo
Honda
Mitsubishi
Honda
Mazda
AUDI AVS
VW CDA
Mercedes
AMG
Source: enTec CONSULTING, Haus der Technik, 2009
45
GLOBAL SHARE OF BOOSTED GASOLINE ENGINES
PER LEADING BRANDS IN THIS CATEGORY
100%
80%
Share of charged Engines of each
OEM´s Global Production - Gasoline
AUDI
BMW
+MINI
VW
60%
Daimler
Ford
40%
FIAT
20%
GM
PSA
• Share of boosted Gasoline
engines also dependent on
product portfolio (entry level
vehicles  NA)
• Daimler following NA-GDI
stratified charge
• BMW most aggressive in
downsizing even with lower
cylinder number
Source: IHS 09/2011
0%
2009 2010 2011 2012 2013 2014 2015 2016 2017
46
BMEP BENCHMARK WITH
PASSENGER CAR GDI-TC
Brake Mean Effektive Pressure [bar]
30
BMW 2.0
28
N20
26
Technical Features
24
22
Engine
Charging
Camphaser
BMW
2.0
N20
1 TC
Twin scroll
IN+EX
AUDI 1.8
T
EA888Gen 3 1
1 TC
Single
scoll
IN+EX
Alfa 1.8
Fam.B
1.75 TBI
1 TC
Single
scroll
IN-EX
20
18
16
14
12
10
8
Var.
Valve
Lift /
Charge
Motion
IN
continuos
EX 2step +
Tumble
flap-
Exh.
manifold
Sheet
metal
welded
TC
Integrated
CI
welded
6
1000
2000
3000
4000
5000
6000
Engine Speed [rpm]
47
BMEP BENCHMARK WITH
30
28
26
Technical Features
24
22
20
Engine
Charging
Camphaser
BMW
2.0
N20
1 TC
Twin scroll
IN+EX
AUDI 1.8
T
EA888Gen 3 1
1 TC
Single
scoll
IN+EX
Alfa 1.8
Fam.B
1.75 TBI
1 TC
Single
scroll
IN-EX
BMW 2.0
N20
18
16
14
Audi 1,8 T
EA 888 Gen 3
12
10
8
Var.
Valve
Lift /
Charge
Motion
IN
continuos
EX 2step +
Tumble
flap-
Exh.
manifold
Sheet
metal
welded
TC
Integrated
CI
welded
6
1000
2000
3000
4000
5000
6000
Engine Speed [rpm]
48
BMEP BENCHMARK WITH
Technical Features
30
28
26
Alfa 1.8
Fam.B 1.75 TBI
80 kW/l >90 kW/l
Engine
Charging
Camphaser
BMW
2.0
N20
1 TC
Twin scroll
IN+EX
AUDI 1.8
T
EA888Gen 3 1
1 TC
Single
scoll
IN+EX
Alfa 1.8
Fam.B
1.75 TBI
1 TC
Single
scroll
IN-EX
24
22
20
BMW 2.0
N20
18
16
14
Audi 1,8 T
EA 888 Gen 3
12
10
8
6
1000
2000
3000
4000
5000
6000
Var.
Valve
Lift /
Charge
Motion
IN
continuos
EX 2step +
Tumble
flap-
Exh.
manifold
Sheet
metal
welded
TC
Integrated
CI
welded
Alfa 1.8: Sophisticated software as
enabler for aggressive scavenging
 competitive performance w/o
expensive components (variable valve
lift, Twinscroll-TC, etc.)
Engine Speed [rpm]
49
EVOLUTION OF TURBOCHARGED GDI
24
BMEP [bar]
22
Significant improvements by:
•refined combustion systems
•increased functionality of the
valve train
•improved exhaust gas cooling
(water cooled / integrated
exhaust manifold, water
cooled turbine housing)
20
18
16
14
12
13
20
5
200
MY 2005
MY 2007
MY 2009
MY 2010
MY 2013
340
BSFC [g/kWh]
320
300
280
260
240
RON 95
220
1000
2000
3000
4000
Engine Speed [rpm]
5000
6000
50
Cam Timing for TGDI: Exhaust VVL; Intake VVL for Miller
IN‐Lo
Short exhaust camshaft
for scavenging at low
engine speed
IN‐Hi
EX‐Lo
Long exhaust camshaft
for part load and high
speed
EX‐Hi
Early intake
closing for
Miller
53
BSFC Maps of Current and future GTDI Technology
Contribution from VVA Systems:
VVL for Exhaust
Miller VVL for Intake
180
180
100
160
Engine Torque [Nm]
80
60
300
40
120
0
25
35
100
0
20
0
140
250
120
260
250
140
275
Engine Torque [Nm]
160
80
1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000
Engine Speed [rpm]60
23 0
40
2 40
275 300
20
Future engines
offer wider 3sweet
spot
50
0
area and more
favorable full load
1000 1500 2000 2500 3000 3500 4000 4500 5000
Engine Speed [rpm]
5500 6000
54
7-Speed Transmission with Current and Future Engines
7-Speed Transmission
7-Speed Transmission
10
10
Best Efficiency
8
Traction Force – kN
Traction Force – kN
8
6
4
6
4
2
2
Road Load
0
0
20
40 60
80 100 120 140 160 180 200
0
0
Road Load
20
40 60
80 100 120 140 160 180 200
55
4-Speed Transmission enhanced with e-Motor
Hybridization allows
electric driving at low
power requirements
where the ICE would
otherwise operate
inefficiently
+
recharging
operation
Road Load
0
20
40 60
80 100 120 140 160 180 200
56
1. Market Trends
•CO2 Reduction
58
Principles and Functional Categories of CVVL Systems
(Continuously Variable Valve Lift)
Direct Acting VVL
Mechanic or
Electrohydraulic
Electromagnetic
EMVT (camless)
Electrohydraulic
EHVS (camless)
CVVL (Continuously Variable
Valve Lift) Systems shall offer
unlimited flexibility for:
•de-throttling in part load
•controlling timing/duration
within complete map.
Besides of system oncost the
energy demand as well as
operational safety has to be
considered very carefully.
59
CSI Engine (Compression and Spark Ignition)
Electro hydraulic
solenoid valve for
internal EGR control
Spark Plug for
conventional spark
ignited mode
Cam phaser
intake
EHVA
AVL - tappet
EHVA
tappet
Switchable
tappet intake
Piston shape for
strat. idle operation
Gasoline direct
injection
63
CSI ENGINE LAYOUT – OPERATION STRATEGY
Operation range and different combustion modes
Exhaust Valves
Intake Valves
1x Exhaust Valve hydraulically
Direct Injection
BMEP
HCSI - = 1,0
HCSI -  = 1,0 + int. EGR
HCCI -  > 1,0
SCSI -  > 1,0
Engine Speed
64
COMBUSTION MODE TRANSITION
Smooth transient by applying transition algorithm
SI
HCCI
MFB50% [deg CA]
20
15
10
5
0
-5
-10
-15
Switching algorithm activ (0.7s)
Cyl. press. rise [bar/°CA]
-20
10
8
6
4
2
0
40
45
50
55
60
65
70
75
80
Cycle
66
1. Market Trends
•CO2 Reduction
67
MARKET & TECHNOLOGY TRENDS
GASOLINE ENGINES
Technology
Cam Phaser
Variable Valve Lift
2 / 3 Step
Variable Valve Lift
Continuous
Cylinder
Deactivation
NA Homogeneous
GDI
TC Homogeneous
MPI / GDI
Huge diversivication
of base technologies
Friction reduction +
energy management
as add-on for all
technologies
GDI Stratified
Controlled Auto
Ignition
Highly sensitive
balancing of costto benefit-ratio
Reduced
parasitic
losses
Improved
thermal
management
Energy
recovery
Start / Stop
Hybridization
……
68
MARKET & TECHNOLOGY TRENDS
GASOLINE ENGINES (April 2013)
Technology
Micro PC
Engines
< 1,0 l
Small PC
Engines
1,0 - 1,5 l
Medium PC
Engines
1,5 - 2,4 l
Large PC
Engines
> 4 cyl
LDT / MDT
Truck
Cam Phaser
General Market
Trends:
New /current
Mainstream:
Variable Valve Lift
2 / 3 Step
Variable Valve Lift
Continuous
Cylinder
Deactivation
NA Homogeneous
GDI
TC Homogeneous
MPI / GDI
?
GDI Stratified
Controlled Auto
Ignition
?
?
?
?
?
note: general worldwide trends, local trends might differ
69
NEDC FUEL ECONOMY POTENTIAL RELATED TO
FORMER AND NEW BASELINE TECHNOLOGY LEVEL
Technology
Former Baseline:
4V – NA MPFI
New Baseline:
4V –GDI –TCI
2–4%
-
Variable Valve Lift
2 / 3 Step
5–8%
2–3%
Variable Valve Lift
Continuous
6 – 10%
3–5%
4 – 8%
3–6%
NA Homogeneous
GDI
1 – 3%
-
TC Homogeneous
MPI / GDI
5 – 14%
-
10 – 15%
4–8%
8 – 13%
3–7%
Cam Phaser
Cylinder
Deactivation
GDI Stratified
Controlled Auto
Ignition
New Gasoline Base Technology
Miller/high
EGR as
alternative
for stratified
lean
5-10%
Options for Further Improvement
70
Conclusion, Outlook for Future VVA Systems
• Technology will continue to extend the efficiency of internal
combustion engines.
• It is assumed that most of future engines will have VVA system in
very different degree of sophistication and complexity.
• Switchable valve lift quickly will rise in numbers, cam phaser will
become standard with gasoline engines (Diesel will follow with
smaller extent)
• Competition of VVA systems will continue, but not as stand alone
feature, but even more to provide benefits complementary to other
technologies.
• System oncost for mechanics and controls, as well as energy
consumption of VVA system have to be assessed very carefully.
71
Thank you very much
for your kind attention !
72
Abbreviations (1/3)
ADD
Aggressive Downsized Diesel
AER
All Electrical range
BMEP
Brake Mean Effective Pressure (spec. value for engine torque)
BSFC
Brake Specific Fuel Consumption
CAI
Controlled Auto Ignition (general expression for HCCI)
CBR
Controlled Burn Rate (AVL patented combustion system for var. charge motion)
CNG
Compressed natural Gas
CSI
Compression and Spark Ignition (AVL patented comb. system featuring HCCI)
DDE
Derated Diesel Engine
DeNOx
Nitrogen oxide reducing catalyst
DVCP
Double Variable Cam Phaser
DPF
Diesel Particulate Filter
EGR
Exhaust Gas Recirculation
EURO6
European Emission Limit Stage 6
EV
Electric Vehicle
FE
Fuel Economy
74
Abbreviations (2/3)
FTP
Federal Test Procedure (USA)
GDI
Gasoline Direct Injection
Gen.1
Generation 1 (first development stage of engine technology)
HCCI
Homogeneous Charge Compression Ignition
HSDI
High Speed Direct Injected (Diesel)
ITW
Vehicle Inertia Test Weight (curb weight)
LNT
Lean NOx Trap
LPG
Liquified Petrol Gas
MPI
Multipoint Port Fuel Injection
MPV
Multi Purpose Vehicle
MY
Model Year
NA
Naturally Aspirated
NEDC
New European Driving Cycle
OBD
On Board Diagnosis
OEM
Original Equipment Manufacturer (=brand)
ROW
Rest of the World
75
Abbreviations (3/3)
PEMS
Portable Emission Measurement System
RDE
Real Driving Emission
RPM
Revolutions per Minute (engine speed)
SCR
Selective Catalytic Reduction (for NOx)
SI
Spark Ignited
SULEV
Super Ultra Low Emission Vehicle (US, California Emission Standard)
SUV
Sport Utility Vehicle
TCI
Turbo Charged Intercooled
TWC
3-Way Catalyst
VVL
Variable Valve Lift
VVT
Variable Valve Timing
WLTP
World Harmonised Light Duty Vehicle Test Procedure
76
77
Advanced combustion and engine
integration of a Hydraulic Valve
Actuation system
Romain LE FORESTIER
Volvo Group Trucks Technology
VVA conference - University of Pitesti - Romania
1
April 18th 2013
Content
 Introduction
 Engine concept
 Results
– Miller cycle on A25 (1200 rpm – 25% load)
– Miller cycle results B25 and C25 (1500 rpm & 1800 rpm – 25%
load)
– Optimization on B25 and B50 (1500 rpm - 25% and 50% load)
 Conclusion on pHCCI combustion
 Hydraulic Valve Actuation features
 Next tests
Content
 Introduction
 Engine concept
 Results
load)
 Next tests
+ Clean with 3-way
Catalyst
- Poor low & part load
Combustion concepts
efficiency
+ High efficiency
- Emissions off NOx
and soot
Background
Spark Ignition (SI)
engine (Gasoline, Otto)
+ High efficiency
+ Ultra low NOx
Compression Ignition
(CI) engine (Diesel)
Homogeneous Charge
(HCCI)
Partly
Homogeneous
Compressed
Combustion
Ignition (pHCCI)
Spark Assisted
(SACI)
Gasoline HCCI
- Combustion control
- Power density
+ Injection controlled
- Less emissions
advantage
Source: Bengt Johansson, Lund Univ.
pHCCI = PCI = PPC = PCCI…
•
pHCCI: One name of several for low NOx/ low soot combustion region
Content
 Introduction
 Engine concept
 Results
load)
 Next tests
Engine Concept – HVA VGT-EGR SST
•
Engine: Volvo Diesel 10,8L displacement.
US04 base
•
360hp at 1800 rpm; 1750 Nm at 1200
rpm
•
FIE: Bosch APCRS B-sample6x745cc/30sx140°
•
Cylinder unit: piston ratio 16:1
•
Air management: VGT – short route EGR
•
Valvetrain: hydraulic valve actuation
Content
 Introduction
 Engine concept
 Results
load)
 Next tests
•
Use of Miller effect by modifying the IVC (Intake Valve Closing), equivalent in this case
to modify the Intake Valve Opening duration
Classic mechanical intake valve
14 Classic mechanical exhaust valve
Close angle 340°, duration 200°
Open angle 380°, duration 75°
1
12
1.2
Intake and Exhaust Valve lifts
Mechanical classic lifts vs. Camless lifts
10
lift [mm]
0.8
Exhaust valve
8
Intake valve
0.6
6
0.4
4
Earl Miller Late Miller
2
0.2
0
0
0
45
90
135 180 225 270 315 360 405 450 495 540 585 630 675 720
Crank1 Angle
Effective Compression Ratio
•
Effective compression ratio range
from 10 to 16 with both Early and
Late Miller effect
17
16
15
14
13
12
11
10
9
70
90
110
130
150
170
190
210
230
250
Intake valve opening duration [°CA]
80
•
A25. Impact on cylinder pressure at
top dead center with an early Miller
setting: 90° intake valve opening
duration instead of 160°
Cylinder Pressure [bar]
70
60
Reference
Early Miller
Injector pulse
50
40
30
20
10
0
-60
-40
-20
0
20
Crank angle degree
40
60
Intake Valve Opening duration sweep on A25 1200 rpm – 25% Load
All other parameters kept constant
Soot
Relative Soot [%]
100
50
0
70
90
110
130
150
170
190
210
230
250
-50
5
0
NOx
20
110
130
150
170
190
210
230
250
EGR [%]
0
110
130
150
170
190
210
230
250
230
250
EGR
40
10
90
90
-5
Relative Nox [%]
10
70
-100
-10 70
BSFC
15
relativ BSFC [%]
•
•
35
30
25
-20
-30
20
70
-40
A25 - 1200 rpm 438 Nm - 5 bar BMEP
reference 160°CA inlet valve opening duration
Early Miller 90°CA inlet valve opening duration
Late Miller 240°CA inlet valve opening duration
90
110
130
150
170
190
210
SNOx AVL439 soot BSFC Temp af.turb.
%
%
%
°C
reference reference reference
315
-5
-54
+6
419
-28
-59
+4
395
A25 1200 rpm - 25% load
Relative CO [%]
3000
200
2500
CO
HC
2000
1500
150
100
1000
50
500
0
0
70
•
Relative HC[%]
250
3500
90
110 130 150 170 190 210 230
Intake valve opening duration [°C A]
250
HC and CO increase with early and late Miller
Exhaust temp after
turbine [°C]
A25 1200 rpm - 25% load - Exhaust temp. After turbine
500
450
400
350
300
70
•
90
110 130 150 170 190 210
230
250
Temperature after turbine increase with Miller
Rate of Heat Release comparison between Early Miller 90°CA intake
ROHR filt.reference 160° intake duration J/°CA
duration and no Miller (160°CA intake duration)
ROHR filt.90° intake duration J/°CA
EGR = 34% for reference
 = 16
 = 1.7
CombEff = 99.80%
1000
45
800
40
EGR = 25% for 90° intake duration
 = 12
 = 1.2
CombEff = 98.84%
700
600
35
30
500
25
400
20
300
15
200
10
100
5
0
0
-5
0
5
10
Crank Angle Degree
15
20
Injector current [AU]
RoHr [J/CAD] and Injection
rate [mm3/ms]
900
50
injection rate
•
Intake Valve Opening duration sweep on B25 and C25
•
Exhaust Valve lift, injection timing, VGT position, injection pressure are kept constant
B25 - 1500 rpm 418 Nm - 4.8 bar BMEP
C25 - 1800 rpm 358 Nm - 4.1 bar BMEP
Early Miller 110°CA inlet valve opening duration
%
%
%
°C
301
-33
-45
+4
390
%
%
%
°C
289
-8
-98
+3
365
-3
-88
+2
356
•
Injection timing sweep on B25 with the pre-defined late Miller setting: 230° CA intake
valve opening duration instead of 160°
VGT position, injection pressure are kept constant
B25: Main Timing swing on Late Miller setting
700
B25 1500 rpm - 418 Nm; Optimization around initial Miller
optimum setting
600
0
12
10
500
-20 -4
-2
0
2
4
6
8
10
12
-40
-60
Main Timing Swing
reference w/o Miller before optimization
reference w/o Miller after optimization
-80
-100
ROHR [J/°CA]
Relative Soot [%]
20
ROHR filt. Timing 10°BTDC
ROHR filt.reference
ROHR filt. Timing -3°BTDC
Injection rate Main Timing 10°BTDC
Injection rate Main Timing 2°BTDC
Injection rate Main Timing -3°BTDC
Inj. Pulse Main Timing 10°BTDC
Inj. Pulse Main Timing 2°BTDC
Inj. pulse Main Timing -3°BTDC
8
400
6
300
4
200
2
100
Main Timing [°CA BTDC]
Relative SNOx [%]
0
70
60
50
40
30
20
10
0
Main Timing Swing
reference w/o Miller before optimization
-4
-2
0
2
4
6
Main Timing [°CA BTDC]
8
10
0
-15
B25 1500 rpm - 418 Nm; Optimization around initial Miller
optimum setting
12
-10
-5
0
5
10
Crank angle degree
15
20
25
30
Injector pulse and injection rate
•
B25 1500 rpm - 418 Nm; Optimization around initial Miller optimum
setting: 230°CA intake valve opening duration instead of 160°CA
60
Main Timing Swing
reference w/o Miller before optimization 40
Relative Soot [%]
20
EGR swing with Main Timing -3°CA BTDC
-100
0
-50
50
-20 0
4
3
EGR = 33%
6°CA
-40
8°CA
 = 1.54
2
CombEff = 98.67 -60
%
0
-1
-80
-2 -3°CA
-100
SNOx [%]
SNOx
%
AVL415S Soot
%
BSFC
%
Temp af.turb.
°C
reference 160°CA inlet valve opening
duration, Main Timing 2°BTDC
reference
reference
reference
282
Late Miller 230°CA inlet valve opening
dur. after opt., Main Timing -3°BTDC
-64
-82
+14
393
B25 - 1500 rpm 418 Nm - 4.8 bar BMEP
10°CA
1st: Injection pressure increase on B50 with late Miller setting
•
2nd: Injection timing sweep
•
3rd: EGR increase
Relative Soot [%]
•
B50 1500 rpm - 50% load; Optimization around initial B25 Miller
optimum setting: 230°CA intake valve opening duration
1650 bar
20
0
-20-100
-80
-60
-40
-20
0
200020bar
-5°CA
-40 reference B50 w/o Miller
-60 Prail increase starting from B25 Miller settings
Main Timing Swing
-80 EGR swing at -5°CA Main Timing
reference B50 w/o Miller
-100
Relative SNOx [%]
0°CA
40
60
2°CA
4°CA BTDC
B50. Late Miller setting, late Main Injection, high EGR
Cylinder pressure; 2000 bar injection pressure; Timing -5°BTDC
Injector pulse
600
RoHR
Injection rate
90
Cylinder pressure [bar]
500
70
60
400
50
300
40
30
200
20
100
10
0
0
-30
-20
-10
0
10
20
Crank angle degree
30
40
50
60
Rate Of Heat Release [J/°CA]
and Injection rate [mm3/ms]
80
Content
 Introduction
 Engine concept
 Results
load)
 Next tests
Conclusion from 2005-2007 tests
•
•
•
•
•
•
The combination of low effective compression ratio, relatively high EGR level and
operation close to stoichiometry provides the "no Soot/ no NOx" conditions
pHCCI is only possible at the expense of relatively low combustion efficiency and
high emissions of CO and HC.
Lowest soot values when combustion started after end of injection.
The simultaneous soot and NOx reduction seems to be a combination of good
premixing, due to longer ignition delay, and low local combustion temperature due to
lack of oxygen.
Such "No Soot/ No NOx" conditions cannot be reached on 50% load even if NOxSoot trade off is improved compared to normal reference Diesel combustion without
Miller.
This pHCCI combustion is also very interesting for after treatment systems and
especially SCR
Content
 Introduction
 Engine concept
 Results
load)
 Next tests
HVA system architecture
Low pressure tank
Medium pressure rail
Low pressure tank
High pressure rail
•
One electro-hydraulic actuator per valve
•
Independent oil circuit with low viscosity oil
•
Engine separated oil pump
•
Dedicated control unit (VDM+)
•
High pressure circuit for power (100 / 210 bar)
•
Medium pressure circuit for control (30 / 35 bar)
•
Low pressure circuit for pump loop (1 bar)
HVA system control
SENSOR
SENSOR BOX
Offset (0V)
Amplification (0-2V)
ANALOG FILTERING BOX
 3kHz filtering frequency
 1 pole (-20dB/dec)
ANALOG/DIGITAL CONVERTER
 10kHz sampling
Vent and supply
valves command
FEEDBACK/FEEDFORWARD CONTROLLERS
 Valve open timing
 Valve lift command
 Debounce depth
 Debounce duration
 Valve close timing
 Landing knee command
 Landing rate command
OPEN LOOP MAPS
LIFT CONVERTER
 2nd order polynomial fit
VALVE LIFT CALIBRATION
 Seat (0mm)
 Boost stop (3,5mm)
 Hardstop (12mm)
HVA system flexibility
•
Valve lift timing and duration
10 Valve lift (mm)
9,5
9
8,5
8
7,5
7
6,5
6
5,5
5
4,5
4
3,5
3
2,5
2
1,5
1
0,5
0
-0,5-360 -340 -320 -300 -280 -260 -240 -220 -200 -180 -160 -140 -120 -100 -80
Crankshaft angle (deg)
-60
•
•
•
Valve lift height
Valve landing velocity
10
Valve lift (mm)
9,5
9
8,5
8
7,5
7
6,5
6
5,5
5
4,5
4
3,5
3
2,5
2
1,5
1
0,5
0
-0,5-360 -340 -320
-300
-280
-260
-240
-220
-200
-180
-160
-140
•
•
•
•
Valve lift height
Valve events per cycle
10 Valve lift (mm)
9,5
9
8,5
8
7,5
7
6,5
6
5,5
5
4,5
4
3,5
3
2,5
2
1,5
1
0,5
0
-0,5-360 -300 -240
-180
-120
-60
0
60
120
180
240
300
360
•
•
•
•
•
Valve lift height
Valve opening velocity
10
Valve lift (mm)
9,5
9
8,5
8
7,5
7
6,5
6
5,5
5
4,5
4
3,5
3
2,5
2
1,5
1
0,5
0
-0,5
-360
-340
-320
172bar
-300
-280
-260
-240
-220
-200
138bar
-180
-160
•
•
•
•
•
•
Valve lift height
Valve opening velocity
Intake valve opening
10
Valve lift (mm)
9,5
9
8,5
8
7,5
7
6,5
6
5,5
5
4,5
4
3,5
3
2,5
2
1,5
1
0,5
0
-0,5-420 -400 -380 -360 -340 -320 -300 -280 -260 -240 -220 -200 -180 -160
HVA system performances
•
Comparison with cam-driven valve lifts
Mechanical actuation versus hydraulic actuation at low engine speed
Mechanical actuation versus hydraulic actuation at high engine speed
HVA system performances
•
Accuracy and repeatability
Lift accuracy: +/- 0,2 mm (<3,5mm)
+/- 0,5 mm (>3,5mm)
Open flank duration: < 3 ms
Open timing accuracy: +/- 2 crdeg
Open flank duration: < 3 ms
Close timing accuracy: +/- 3 crdeg
Content
 Introduction
 Engine concept
 Results
load)
 Next tests
Since 2007, confidential tests performed
• Cylinder de-activation
•
•
•
•
What is the impact on fuel?
How much does it improve heat-up
How many cylinders shall be de-activated?
At which load is cylinder de-activation beneficial?
• Exhaust valve re-opening during intake stroke
• Is it beneficial with VGT or FGT?
• What is the impact in transient?
• At which load is exhaust valve re-opening beneficial?
• How much can it limit exhaust temperature?
• Miller effect using exhaust valve instead of intake valve
• Is it beneficial for Early and/or for late Miller?
• What is the impact on NOx?
• What is the impact on fuel?
Thank you!
VVA technique as a way to improve SIE efficiency.
Results obtained at the University of Pitesti in
close cooperation with le Cnam Paris
1,2Adrian
1University
Adrian CLENCI
CLENCI, 2Pierre PODEVIN
of Pitesti, Automotive and Transports Department
2 Le Cnam de Paris, LGP2ES, EA21
18/04/2013
Results obtained at the University of Pitesti in cooperation with Cnam Paris

Introduction
Experimental results
CFD Simulation
Conclusions
Adrian CLENCI
18/04/2013
2/24
INTRODUCTION
Internal Combustion Engine
=
(still) the main energy source for ensuring road mobility
Problem:
Negative impact on the environment
(fuel consumption and pollution)
EU Regulation no 443/2009
130 g CO2/km in 2015 & 95 g CO2/km in 2020
Adrian CLENCI
18/04/2013
3/24
INTRODUCTION
Adrian CLENCI
18/04/2013
4/24
INTRODUCTION
Overall engine efficiency needs to be improved
rather under low loads and speeds where the overall efficiency decreases
from the not very high peak values (35%) to dramatically lower values (< 10%)
Engine operation area during NEDC – sfc[g/KWh] @ NA engine
VARIABLE VALVE ACTUATION
Adrian CLENCI
18/04/2013
5/24
INTRODUCTION
Sinergy
Adrian CLENCI
18/04/2013
6/24
INTRODUCTION
HARA ViVL
OHC
OHV
Adrian CLENCI
18/04/2013
7/24
Introduction
 Experimental results
CFD Simulation
Conclusions
Adrian CLENCI
18/04/2013
8/24
EXPERIMENTAL RESULTS
Main parameters of the HARA ViVL PFI SI engine prototype
Number of cylinders
4
Stroke [mm]/Bore[mm]
77/76
Volumetric Compression Ratio
9.0
Combustion chamber
Wedge type; 2 valves
Exhaust Valve Law
Minimum Intake Valve Law
(Hmin)
Maximum Intake Valve Law
(Hmax)
Adrian CLENCI
18/04/2013
Maximum Valve Lift, MVL [mm]
7.5
Exhaust Valve Opening, EVO [°CA BBDC]
73
Exhaust Valve Closing, EVC [°CA ATDC]
42
1.165
Intake Valve Opening, IVO[°CA ATDC]
19
Intake Valve Closing, IVC [°CA ABDC]
29
8.275
Intake Valve Opening, IVO [°CA BTDC]
15
Intake Valve Closing, IVC [°CA ABDC]
73
9/24
Lifting laws
Idle operation @ 800 rpm. Stoechiometric operation
9
BDC
TDC
Hmax
BDC
8
7
Valve Lift [mm]
6
5
Variable
4
Exhaust
Intake
3
2
Hmin
1
0
0
60
120
180
240
300
360
[ºCA]
Adrian CLENCI
18/04/2013
10/24
420
480
540
600
660
720
Instrumentation of the engine
Idle operation @ 800 rpm. Stoechiometric operation
Adrian CLENCI
18/04/2013
11/24
Fuel consumption. Cyclic dispersion
Idle operation
800 rpm
Stoechiometric operation
28
25%
1.4
Ch[Kg/h]
Hmax
Hmin
1.2
Improvement[%]
20.2% 20.4%
19.9%
20.9%
24
20%
18.2%
18.2%
Hmax
Hmin
22.9%
18.1%
20
14.4%
0.8
15%
0.6
10%
CoVIMEP[%]
15.6%
Improvement[%]
1.0
16
12
8
0.4
5%
4
0.2
0.0
0%
30
25
20
15
10
5
0
-5
-10
-15
30
IA[ºCA]
Adrian CLENCI
0
25
20
15
10
5
IA[ºCA]
18/04/2013
12/24
0
-5
-10
-15
Indicated diagrams. Heat release
IA = 30° CA
Throttle plate opening:
20,8° Hmin
21,6° Hmax
IA = 30° CA
- Higher peak pressure
ECR = 8.1 for Hmin and 5.8 for Hmax
- Higher RoHR
- Earlier EoC
Adrian CLENCI
18/04/2013
13/24
Conclusions
An improved engine operation at idle for the minimum intake valve law
Causes:
- increased intake flow velocity  increased turbulence 
 improving of the fuel-air mixing process
- a lower amount of residual burned gas as a consequence of a lower IEGR intensity
These two factors led to a better and more repeatable combustion
In order to see the detailed phenomena about the intake flow velocity,
a CFD study was launched.
Adrian CLENCI
18/04/2013
14/24
Introduction
Experimental Results

CFD Simulation
Conclusions
Adrian CLENCI
18/04/2013
15/24
CFD SIMULATION
Geometry. Meshing. Calculation.
0° CA/TDC :
1 231 195 elements
Dynamic Simulation
with
ANSYS-FLUENT:
i.e. the airflow is driven entirely by
the motion of the piston and valves
Turbulence model:
k-ε Realizable
180° CA/BDC :
1 589 954 elements
Adrian CLENCI
18/04/2013
16/24
CFD SIMULATION
Results. Pressure curves. CFD model validation
The motored engine @ 800 rpm was simulated…
…for a 20.8º throttle opening
for the 2 situations: Hmin and Hmax
Adrian CLENCI
18/04/2013
17/24
CFD SIMULATION
Results. Flow velocity fields
Hmin:
αWSA_max = –272°CA
WSA_max = 160 m/s
Hmax:
αWSA_max = –315°CA
WSA_max = 32 m/s
Adrian CLENCI
18/04/2013
18/24
CFD SIMULATION
Results. In-cylinder air mass
10
CFD_Hmin
CFD_Hmax
9
8
7
5
4
3
2
1
0
-375
-350
-325
-300
-275
-250
-225
-200
-175
-150
-125
-100
-75
-50
-25
[ºCA]
A compromise should be done between internal aerodynamics, pumping and filling efficiency
Adrian CLENCI
18/04/2013
19/24
0
p c y l[b a r]
6
CFD SIMULATION
Results. Large scale movements - Swirl
Fluid particles trajectories
SN 

I  2   n
Hmax
Hmin
the trajectories described by the particles are longer at Hmin,
as a result of the intensification of swirl motion
Adrian CLENCI
18/04/2013
20/24
CFD SIMULATION
Results. Turbulent Kinetic Energy & Turbulent Intensity
80
7
75.87
6.21
70
5.92
6
59.46
60
5
Hmin
Hmax
Hmin
Hmax
4
IT[%]
TKE[m2/s2]
50
40
3
2.47
30
2.16
2
20
1.97
1.21
10.35
10
10.09
1
6.94
2.44
1.05
0.81
0.75
0.92
0
0
α_Wmax_air
Adrian CLENCI
α_intake MVL
End of intake stroke
18/04/2013
End of compression
stroke
21/24
α_Wmax_air
α_intake MVL
End of intake stroke
End of compression
stroke
Introduction
Experimental Results
CFD Simulation

Adrian CLENCI
Conclusions
18/04/2013
22/24
CONCLUSIONS
Gasoline engine evolution
Ignition
Air-fuel ratio
Variable Valve Actuation
Fuel economy
Adrian CLENCI
18/04/2013
+ Pollution reduction
23/24
Thank you!
Merci !
Grazie!
Danke Schon!
Multumesc !
Adrian CLENCI
adrian.clenci@upit.ro, adrian.clenci@cnam.fr
University of Pitesti, Automotive and Transports Department
Le Cnam de Paris, LGP2ES, EA21
Adrian CLENCI
18/04/2013
24/24

Variable Valve Actuation (VVA) - Cnam

Transcription

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