Holistic Engine and EAT System Simulationfrom Concept to Series Development
GT Conference 2018
8. October 2018, Frankfurt am Main
Martin Weber, Dr.-Ing. Reza Rezaei, Rico Möllmann, Hendrik Rauch, Dávid Kovács and Christopher Hayduk
Agenda
• Model-based development process
• Virtual field test and evaluation
• Conception with holistic system approach
• Series calibration support
• Summary & Conclusion
IAV 10/2018 TPC1 MW2 Status: released for GT conference2
Agenda
• Model-based development process
• Virtual field test and evaluation
• Conception with holistic system approach
• Series calibration support
• Summary & Conclusion
IAV 10/2018 TPC1 MW2 Status: released for GT conference3
Model-based development process
Concept Development Phase
Focus: Functional Feasibility
Detailed Design
Requirements Analysis
Integration TestingSystem Conception
by CAE
Concept Implementation
System Testing
Module Testing Production Planning
Requirements Refinement
Integration TestingFinal Series Design
Series Implementation
System Testing
Module Testing
Series Development Phase
Focus: Series Production Robustness
Re-use of detailed
concept phase models
Model-based engine and exhaust aftertreatment calibration
Continuous feedback of test results for validation and fine-tuning of component and system models
IAV 10/2018 TPC1 MW2 Status: released for GT conference4
Agenda
• Model-based development process
• Virtual field test and evaluation
• Conception with holistic system approach
• Series calibration support
• Summary & Conclusion
IAV 10/2018 TPC1 MW2 Status: released for GT conference5
Virtual field evaluation and test
IAV 10/2018 TPC1 MW2 Status: released for GT conference6
• Various applications of commercial engines must comply with RDE legislation
• Operation under high-altitude or extreme ambient temperature conditions
• Evaluation of engine calibration in critical field cycles
• Investigation of the effect of thermal management strategies
Main Challenges
• Exhaust temperature increase without fuel consumption deterioration
• Effect on raw emissions as well as EAT performance (NO2/NOX, space
velocity) requires further investigations
• Some field problems (DOC clogging, DPF ashing, etc.) can mostly only be
estimated
MA
N-I
AV
: „V
ari
ab
le v
alv
e tra
ins in
HD
en
gin
es”,
11
th M
TZ
Cha
rge
Exch
an
ge
Con
f, 2
01
6
Holistic system simulation for evaluation of engine and EAT functions
Optimization of thermal management and EAT efficiency for various
applications
On-highway
Hoh
l, Y
ve
s:
“Lie
bh
err
exp
eri
en
ce
with
SC
R o
n f
ilte
r syste
m”,
SA
EH
D S
ym
po
siu
m 2
01
6
Off-highway
Agenda
• Model-based development process
• Virtual field test and evaluation
• Conception with holistic system approach
• Series calibration support
• Summary & Conclusion
IAV 10/2018 TPC1 MW2 Status: released for GT conference7
Conception with holistic system approach
Engine model with predictive combustion and NOx model can replace investigation on test bench
Coupled simulation system enables holistic statement about system behavior in different load cycles
Engine test bench
GT-SUITE engine model
Inlet boundary:
• Exhaust mass flow
• Exhaust gas temp.
• Concentrations
Coupling to
EAT models
GT-SUITE EAT models
IAV 10/2018 TPC1 MW2 Status: released for GT conference8
…
End of pipe
emissions
En
gin
e s
pe
ed
[-]
0.2
0.4
0.6
0.8
1.0
No
rma
lize
d c
um
ula
ted
va
lue
s [-]
0.0
0.1
0.2
0.3
0.4
0.5
Cold start validation cycle time [s]
0 120 240 360 480 600 720 840 960
Cumulated NOx mass Cumulated fuel mass Cumulated exhaust gas mass
Measurement
Simulation
Te
mp
. L
P-
Tu
rbin
e o
ut
50K
En
gin
e to
rqu
e [-]
0.0
0.2
0.4
0.6
0.8
1.0 Measured Simulated
Conception with holistic system approach
IAV 10/2018 TPC1 MW2 Status: released for GT conference9
Engine model
• 12l-HD diesel R6 engine
• 2100 bar CR DI injection
• EGR-emission concept
• Physical modelling approach to ensure predictability
• DI-Pulse combustion model
• IAV-NOx kinetic* implemented as user code reference
• Cold start cycle used to validate the correct behavior
in terms of:
• Torque
• Temperature after low-pressure turbine
• Cumulated NOX mass
• Cumulated exhaust gas mass
Rau
ch
, H
., R
eza
ei, R
., W
eb
er,
M.,
Ko
va
cs, D
. e
t a
l., “H
olistic D
eve
lop
me
nt
of F
utu
re L
ow
NO
x
Em
issio
n C
on
ce
pts
fo
r H
ea
vy-D
uty
Ap
plica
tio
ns,”
SA
ET
ech
nic
al P
ap
er
20
18
-01
-17
00
, 2
01
8
Rezaei, R., Dinkelacker, F., Tilch, B., Delebinski, T., et al., “Phenomenological modeling of combustion and NOX emissions
using detailed tabulated chemistry methods in diesel engines," International Journal of Engine Research 17(8):846-856.
*
Te
mp
. D
OC
in
Measurement Simulation
50K
Cu
mu
late
d N
Ox
tailp
ipe
em
iss
ion
s [
-]
0.0
0.2
0.4
0.6
0.8
1.0
1.2
WHTC cycle time [s]
0 300 600 900 1200 1500 1800
Te
mp
. D
PF
in
50K
Te
mp
. S
CR
in
50K
Baseline aftertreatment system model
• Baseline EAT system with: DOC + DPF + SCR
• Temperatures at DOC, DPF and SCR inlet
show good match to measured temperatures
• AdBlue dosing strategy was implemented as
soft ECU
• Differences in SCR efficiency caused by a
different SCR technology used for validation
Conception with holistic system approach
IAV 10/2018 TPC1 MW2 Status: released for GT conference10
Rau
ch
, H
., R
eza
ei, R
., W
eb
er,
M.,
Ko
va
cs, D
. e
t a
l., “H
olistic D
eve
lop
me
nt
of F
utu
re L
ow
NO
x
Em
issio
n C
on
ce
pts
fo
r H
ea
vy-D
uty
Ap
plica
tio
ns,”
SA
ET
ech
nic
al P
ap
er
20
18
-01
-17
00
, 2
01
8
Conception with holistic system approach
IAV 10/2018 TPC1 MW2 Status: released for GT conference11
DOC DPF SCR
Size [liter] 10.3 26 32
Catalyst technology Pt - Cu-zeolite
Max. NH3 storage [g/l] @ 250 °C - - 1.57
Cell density [cpsi] /
wall thickness [in]
300/
0.006
200/
0.012
300/
0.006
SCRF SCR
Size [liter] 26 5
Catalyst technology Cu-zeolite Cu-Zeolite
Max. NH3 storage [g/l] @ 250 °C 1.57 1.57
Cell density [cpsi] /
wall thickness [in]
200/
0.012
300/
0.006
Stage V baseline EAT system Stage V SCRF + SCR EAT system
• Comparison of two EAT layouts and technologies
• Baseline Stage V system
• SCRF + SCR layout
• Cu-zeolite SCR technology
• Both layouts have the same downpipe length
• Equal SCR size for both layouts
• Equal maximum NH3 of all SCR catalysts
• NH3 storage is initialized empty in all simulations
Rau
ch
, H
., R
eza
ei, R
., W
eb
er,
M.,
Ko
va
cs, D
. e
t a
l., “H
olistic D
eve
lop
me
nt
of F
utu
re L
ow
NO
x
Em
issio
n C
on
ce
pts
fo
r H
ea
vy-D
uty
Ap
plica
tio
ns,”
SA
ET
ech
nic
al P
ap
er
20
18
-01
-17
00
, 2
01
8
Conception with holistic system approach
IAV 10/2018 TPC1 MW2 Status: released for GT conference12
Engine results
• Intake throttling is enhanced by an EGR cooler
bypass during the cold start only
• Intake throttling during low loads increases the
exhaust gas temperature throughout the load cycle
• EGR cooler bypass increases the exhaust gas
temperature and engine out NOx emissions
Fastest EAT heat up expected with cold start
optimized combustion calibration + intake
throttle + EGR cooler bypass
Cold start NRTC
En
gin
e s
pe
ed
[rp
m]
600
1000
1400
1800
2200
En
gin
e t
orq
ue [
Nm
]
-500
0
500
1000
1500
2000
2500
Tem
p.
LP
-tu
rbin
e
ou
t [d
eg
C]
050
100150200250300350400
NRTC cycle time [s]
0 300 600 900 1200
EGRcBypass
Comb. cal. 1 Comb. cal. 2 Comb. cal. 2 + intake throttle
Comb. cal. 2 + intake throttle + EGRcBypass
Comb. cal. 2 Comb. cal. 1
Rau
ch
, H
., R
eza
ei, R
., W
eb
er,
M.,
Ko
va
cs, D
. e
t a
l., “H
olistic D
eve
lop
me
nt
of F
utu
re L
ow
NO
x
Em
issio
n C
on
ce
pts
fo
r H
ea
vy-D
uty
Ap
plica
tio
ns,”
SA
E T
ech
nic
al P
ap
er
20
18
-01
-17
00
, 2
01
8
• Comb. cal. 1: High efficiency mode, low exhaust
gas temperature as “normal operation”
• Comb. cal. 2: Retarding of SOI and lowering of
boost pressure as heating measures
Baseline EAT results
• SCR storage initialized as empty
• Limited AdBlue dosage release at 200°C at SCR
inlet to prevent blocking
• AdBlue dosing with pre control & NH3 storage
controller
• NOx reduction by approx. 40% achieved with intake
throttle and combustion calibration 2
Conception with holistic system approach
IAV 10/2018 TPC1 MW2 Status: released for GT conference13
Fast heat up of EGR cooler bypass can’t
compensate the higher raw NOx emission
Rau
ch
, H
., R
eza
ei, R
., W
eb
er,
M.,
Ko
va
cs, D
. e
t a
l., “H
olistic D
eve
lop
me
nt
of F
utu
re L
ow
NO
x
Em
issio
n C
on
ce
pts
fo
r H
ea
vy-D
uty
Ap
plica
tio
ns,”
SA
ET
ech
nic
al P
ap
er
20
18
-01
-17
00
, 2
01
8 Te
mp
. S
CR
in
[d
eg
C]
100
150
200
250
300
350
AdBlue dosage release
SC
R N
H3
sto
rag
e l
eve
l [g
/l]
0.0
0.10.20.30.40.50.6
Comb. cal. 1
Comb. cal. 2 Comb. cal. 2 + intake throttle Comb. cal. 2 + intake throttle + EGRcBypass
Cu
mu
late
d N
Ox t
ail-
pip
e e
mis
sio
ns
[g
]
05
10152025303540
NRTC cycle time [s]
0 300 600 900 1200
871 mg/kWh
680 mg/kWh569 mg/kWh
514 mg/kWh
Cold start NRTC
SCRF + SCR EAT results
• NH3-slip over SCRF is needed to distribute NH3 to
the SCR
• After cold start, thermal management is needed to
prevent the EAT from cooling down
Conception with holistic system approach
IAV 10/2018 TPC1 MW2 Status: released for GT conference14
Rau
ch
, H
., R
eza
ei, R
., W
eb
er,
M.,
Ko
va
cs, D
. e
t a
l., “H
olistic D
eve
lop
me
nt
of F
utu
re L
ow
NO
x
Em
issio
n C
on
ce
pts
fo
r H
ea
vy-D
uty
Ap
plica
tio
ns,”
SA
ET
ech
nic
al P
ap
er
20
18
-01
-17
00
, 2
01
8
Te
mp
. S
CR
F in
[d
eg
C]
050
100150200250300350
AdBlue dosage release
Comb. cal. 1
Comb. cal. 2 Comb. cal. 2 + intake throttle Comb. cal. 2 + intake throttle + EGRcBypass
SC
RF
NH
3 s
tora
ge
lev
el
[g/l
]
0.00
0.05
0.10
0.15
0.20
SC
RF
NH
3 s
lip
[p
pm
]
0
50
100
150
200
250
SC
R N
H3
sto
rag
e le
vel
[g/l
]
0.00.10.20.30.40.50.60.70.8
SCRF NH3 slip
leads to NH 3
storage in SCR
Cu
mu
late
d N
Ox t
ail
-p
ipe
em
iss
ion
s [
g]
0
510152025
30
NRTC cycle time [s]
0 300 600 900 1200
700 mg/kWh
570 mg/kWh
382 mg/kWh
377 mg/kWh
Fast heat up of EGR cooler bypass can’t
compensate the higher raw NOx emission
Baseline EAT: 514 mg/kWh
SCRF + SCR EAT: 377 mg/kWh
- 27 %
Cold start NRTC
Conception with holistic system approach
IAV 10/2018 TPC1 MW2 Status: released for GT conference15
Conclusion
• In a coupled simulation environment, different
thermal management measures can be
investigated
• The effect on different EAT systems and
therefore deNOx efficiency is clearly visible
• SCRF systems can improve the trade-off
between fuel consumption and NOx emission
The NOX-/be trade-off can be loosened by
the investigation of different EAT layouts
230
232
234
236
238
300 400 500 600 700 800 900
Fu
el c
on
su
mp
tio
n [
g/k
Wh
]
NOx tailpipe emissions [mg/kWh]
Baseline EAT
SCRF + SCR
Cold start NRTC
Rau
ch
, H
., R
eza
ei, R
., W
eb
er,
M.,
Ko
va
cs, D
. e
t a
l., “H
olistic D
eve
lop
me
nt
of F
utu
re L
ow
NO
x
Em
issio
n C
on
ce
pts
fo
r H
ea
vy-D
uty
Ap
plica
tio
ns,”
SA
ET
ech
nic
al P
ap
er
20
18
-01
-17
00
, 2
01
8
Comb. cal. 1Comb. cal. 2
Comb. cal. 2 + intake throttle
Comb. cal. 2 + intake throttle + EGRcBypass
Agenda
• Model-based development process
• Virtual field test and evaluation
• Conception with holistic system approach
• Series calibration support
• Summary & Conclusion
IAV 10/2018 TPC1 MW2 Status: released for GT conference16
Series calibration supportCalibration of DPF soot load detection
• Calibration of the ECU DPF soot
load detection nearly impossible
without physico-chemical models
• Passive and active regeneration
are modelled physico-chemically
in GT-Suite
• Model-based calibration of the
ECU functionality
• Validation of the models against
DPF weighting on engine test
bench is necessaryEngine or catalytic
test bench
Pre-calibrated
ECU model
3: Optimization of the
ECU model
Endurance
run with DPF
weighting
1: Calibration of the
physico-chemical model
2: Calibration of
fast- running
ECU model
Validated physico-
chemical model
Validated and
optimized ECU model
IAV 10/2018 TPC1 MW2 Status: released for GT conference17
Series calibration supportCalibration of DPF soot load detection
IAV 10/2018 TPC1 MW2 Status: released for GT conference18
Calibration of fast-running ECU model from
physico-chemical model
• Soot mass in DPF is kept constant via
PI controller
• Inlet boundaries are varied from case to
case to find the characteristics of the DPF
• Passive and active regeneration can be
investigated & calibrated
Model-based calibration of the
DPF soot burn functionality
PI controller
• Inlet concentrations
• Exhaust gas mass flow
• Exhaust gas temperature
• Outlet concentrations
• Soot mass in DPF
dmSoot,DPFus mSoot,DPF
DPF
model
Target DPF
soot mass
Series calibration supportCalibration of DPF soot load detection
IAV 10/2018 TPC1 MW2 Status: released for GT conference19
• DPF soot load measured in various load cycles
• Predictions of engine ECU show good fit with measured soot load
for different cycles
• Multiple soot regeneration strategies are evaluated in real cycles
• Active regeneration was achieved by late post injection
• ECU soot burn model is able to describe burned soot mass
precisely
Evaluation of DPF soot model in multiple real field cyclesDP
F s
oot
mass [
g]
0
20
40
60
80
100
Time [s]
0 600 1200 1800 2400 3000 3600 4200 4800
Calculated soot mass by ECU Measurement
Tem
pera
ture
[°C
]
0
150
300
450
600
750 Exhaust gas Temperature after DPF
PM
[g]
0
20
40
60
80
100
Time [h]
0 20 40 60 80 100 120 140 160 180
WHTC ECU WHTC Low Load Driving Cycle 1 ECU Low Load Driving Cycle 1 Low Load Driving Cycle 2 ECU Low Load Driving Cycle 2
Agenda
• Model-based development process
• Virtual field test and evaluation
• Conception with holistic system approach
• Series calibration support
• Summary & Conclusion
IAV 10/2018 TPC1 MW2 Status: released for GT conference20
Summary and conclusion
• Diversity in applications and therefore in load collectives in HD applications
• The holistic engine and EAT optimization approach is introduced and evaluated by IAV
• Main targets of holistic system evaluation are:
Engine emission concept development and EAT design optimization
Testing comb. system and EAT concept and calibration under real field cycles
Evaluation of RDE conformity problems in critical customer cycles
• Series calibration tasks can be supported with physico-chemical modelling in GT Suite
Holistic engine and EAT system optimization for virtual concept development, ensuring PEMS
conformity, preventing field issues in real field cycles!
IAV 10/2018 TPC1 MW2 Status: released for GT conference21
Contact
M. Sc. Martin Weber
Advanced Engineering & Model Based Development
Commercial Vehicle Powertrain
IAV GmbH
Nordhoffstraße 5, 38518 Gifhorn (Germany)
www.iav.com
Series calibration supportHigh altitude engine calibration
Validation setup at IAV test bench with altitude simulator (Altitudes up to 4000m possible)
IAV 10/2018 TPC1 MW2 Status: released for GT conference23
Pressure downstream turbine is
controlled with a compressor
EGR-cooler
intercooler
turbine
compressor
air filter
Pressure upstream compressor
is controlled with a throttle valve
engine
Tu
rbo
ch
arg
er
Sp
ee
d [
10
00
/min
]
80
90
100
110
120
130
140
En
gin
e o
ut
tem
pe
ratu
re [
K]
650
700
750
800
850
900
950
Operation Point
1 2 3 4 5 6 7 8 9 10
measured values simulated values 50 m
To
rqu
e [
Nm
]
Engine Speed [rpm]
1000 1500 2000 2500 3000
4
7
10
3
6
9
2
5
8
1
Series calibration supportHigh altitude engine calibration
Model was calibrated only
for height of 50 m
No further calibration with
high altitude conditions
Simulation shows good match with test bench data
IAV 10/2018 TPC1 MW2 Status: released for GT conference24
Tu
rbo
ch
arg
er
Sp
ee
d [
10
00
/min
]
80
90
100
110
120
130
140
En
gin
e o
ut
tem
pe
ratu
re [
K]
650
700
750
800
850
900
950
Operation Point
1 2 3 4 5 6 7 8 9 10
measured values simulated values 50 m 2000 m
Tu
rbo
ch
arg
er
Sp
ee
d [
10
00
/min
]
80
90
100
110
120
130
140
En
gin
e o
ut
tem
pe
ratu
re [
K]
650
700
750
800
850
900
950
Operation Point
1 2 3 4 5 6 7 8 9 10
measured values simulated values 50 m 2000 m 3500 m
Full Load 90% Load 75% Load
Innovative raw emission modeling approach
IAV 10/2018 TPC1 MW2 Status: released for GT conference25
IAV tabulated NOx
kinetics show
improved accuracy
compared to Zeldovich
NO
x [
ppm
]
Case [-]
1 2 3 4 5 6 7 8 9
Measured Simulated with the DI-Pulse combustion model,
using the tabulated NOx kinteics Simulated with the DI-Pulse combustion model,
using the Zeldovich mechanism
Torq
ue [
Nm
]E
ngin
e s
peed [
1/m
in]
Engine speed Torque
400
300
Me
an
effe
ctive
pre
ssu
re [b
ar]
Engine speed [1/min]
600 900 1200 1500 1800 2100
OP4
OP5
OP6
OP1
OP2
OP3
OP7
OP8
OP9Phenomenological
Modeling
Physics based
Data-driven
Modeling
Empirical (DoE)
NOx
Soot
HC
CO
• For most applications, a
phenomenological NOx
model can be calibrated to
a good fit
• The formation of other
pollutants is highly
dependent on 3D in-
cylinder processes
Much harder to model
• Empirical models can
improve the prediction of
other pollutants
123
4
5
6
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8
9
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6263
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69
qin
j [m
g]
Engine speed [1/min]
Soot [F
SN
]
Case [-]
0 10 20 30 40 50 60 70
Measured class. Model
0.1 FSN
Soot [F
SN
]
Case [-]
0 10 20 30 40 50 60 70
Measured class. Model hybr. Model
0.1 FSN
Innovative raw emission modeling approach
• Validation of models based on different operating points
• Emission models were not trained with the validation points below
Hybrid emission modeling approach is investigated in the IAV internal research activity
“Classical”
DoE
emission
model
Hybrid
emission
model
(GT + DoE)
nEng
mFuel
λExhaust
SOImain
TCyl,max
…
λExhaust
EGR + res. gas
COHR
TCyl,max
Ignition delay
Burn duration
…
IAV 10/2018 TPC1 MW2 Status: released for GT conference26