Spark-assisted compression ignition (SACI) offers more practical combustion phasing control and a lower pressure rise rate than homogeneous charge compression ignition (HCCI) combustion and improved thermal efficiency and lower NOx emissions than spark ignition (SI) combustion. Any practical passenger car engine, including one that uses SACI in part of its operating range, must be robust to changes in ambient conditions. This study investigates the effects of ambient temperature and humidity on stoichiometric SACI combustion and emissions. It is shown that at the medium speed and load SACI test point selected for this study, increasing ambient air temperature from 20 °C to 41 °C advances combustion phasing, increases maximum pressure rise rate, causes a larger fraction of the charge to be consumed by auto-ignition (and a smaller fraction by flame propagation), and increases NOx. Increasing ambient humidity from 32% to 60% retards combustion phasing, reduces maximum pressure rise rate, increases coefficient of variation (COV) of indicated mean effective pressure (IMEP), reduces NOx, and increases brake-specific fuel consumption (BSFC). These results show that successful implementation of SACI combustion in real-world driving requires a control strategy that compensates for changes in ambient temperature and humidity.

References

References
1.
Cracknell
,
R.
,
Ariztegui
,
J.
,
Barnes
,
K.
,
Bessonette
,
P.
,
Cannella
,
W.
,
Douce
,
F.
,
Kelecom
,
B.
,
Kraft
,
H.
,
Lampreia
,
I.
,
Rickeard
,
D. J.
,
Savarese
,
M. C.
,
Williams
,
J.
, and
Rose
,
K. D.
,
2008
, “
Advanced Combustion for Low Emissions and High Efficiency: A Literature Review of HCCI Combustion Concepts
,” CONCAWE, Brussels, Belgium, Report No. 4/08.
2.
Yao
,
M.
,
Zheng
,
Z.
, and
Liu
,
H.
,
2009
, “
Progress and Recent Trends in Homogeneous Charge Compression Ignition (HCCI) Engines
,”
Prog. Energy Combust. Sci.
,
35
(
5
), pp.
398
437
.
3.
Stanglmaier
,
R. H.
, and
Roberts
,
C. E.
,
1999
, “
Homogeneous Charge Compression Ignition (HCCI): Benefits, Compromises, and Future Engine Applications
,”
SAE
Paper No. 1999-01-3682.
4.
Lavoie
,
G.
,
Ortiz-Soto
,
E.
,
Babajimopoulos
,
A.
,
Martz
,
J. B.
, and
Assanis
,
D. N.
,
2012
, “
Thermodynamic Sweet Spot for High-Efficiency, Dilute, Boosted Gasoline Engines
,”
Int. J. Engine Res.
,
14
(
3
), pp.
260
278
.
5.
Manofsky
,
L.
,
Vavra
,
J.
,
Assanis
,
D. N.
, and
Babajimopoulos
,
A.
,
2011
, “
Bridging the Gap Between HCCI and SI: Spark-Assisted Compression Ignition
,”
SAE
Paper No. 2011-01-1179.
6.
Lavoie
,
G. A.
,
Martz
,
J.
,
Wooldridge
,
M.
, and
Assanis
,
D.
,
2010
, “
A Multi-Mode Combustion Diagram for Spark Assisted Compression Ignition
,”
Combust. Flame
,
157
(
6
), pp.
1106
1110
.
7.
Lindhjem
,
C.
,
Chan
,
L.
,
Pollack
,
L.
, and
Kite
,
C.
,
2004
, “
Applying Humidity and Temperature Corrections to On and Off-Road Mobile Source Emissions
,”
EPA 13th International Emission Inventory Conference: Working for Clean Air in Clearwater
, Clearwater, FL, June 8–10.
8.
Rakopoulos
,
C. D.
,
1988
, “
Ambient Temperature and Humidity Effects on the Performance and Nitric Oxide Emission of Spark Ignition Engined Vehicles in Athens/Greece
,”
Sol. Wind Technol.
,
5
(
3
), pp.
315
320
.
9.
Brown
,
W. J.
,
Gendernalik
,
S. A.
,
Kerley
,
R. V.
, and
Marsee
,
F. J.
,
1970
, “
Effect of Engine Intake-Air Moisture on Exhaust Emissions
,”
SAE
Paper No. 700107.
10.
Krause
,
S. R.
,
1971
, “
Effect of Engine Intake-Air Humidity, Temperature, and Pressure on Exhaust Emissions
,”
SAE
Paper No. 710835.
11.
Manos
,
M. J.
,
Bozek
,
J. W.
, and
Huls
,
T. A.
,
1972
, “
Effect of Laboratory Ambient Conditions on Exhaust Emissions
,”
SAE
Paper No. 720124.
12.
Larson
,
R. E.
,
1989
, “
Vehicle Emission Characteristics Under Cold Ambient Conditions
,”
SAE
Paper No. 890021.
13.
Yoon
,
S. H.
, and
Lee
,
C. S.
,
2012
, “
Effect of Undiluted Bioethanol on Combustion and Emissions Reduction in a SI Engine at Various Charge Air Conditions
,”
Fuel
,
97
, pp.
887
890
.
14.
Jamriska
,
M.
,
Lorawska
,
L.
, and
Mergersen
,
K.
,
2008
, “
The Effect of Temperature and Humidity on Size Segregated Traffic Exhaust Particle Emissions
,”
Atmos. Environ.
,
42
(
10
), pp.
2369
2382
.
15.
Andreae
,
M. M.
,
Cheng
,
W. K.
,
Kenney
,
T.
, and
Yang
,
J.
,
2007
, “
Effect of Air Temperature and Humidity on Gasoline HCCI Operating in the Negative-Valve-Overlap Mode
,”
SAE
Paper No. 2007-01-0221.
16.
Aroonsrisopon
,
T.
,
Foster
,
D. E.
,
Morikawa
,
T.
, and
Iida
,
M.
,
2002
, “
Comparison of HCCI Operating Ranges for Combinations of Intake Temperature, Engine Speed and Fuel Composition
,”
SAE
Paper No. 2002-01-1924.
17.
Persson
,
H.
,
Agrell
,
M.
,
Olsson
,
J.
,
Johansson
,
B.
, and
Ström
,
H.
,
2004
, “
The Effect of Intake Temperature on HCCI Operation Using Negative Valve Overlap
,”
SAE
Paper No. 2004-01-0944.
18.
Sjöberg
,
M.
, and
Dec
,
J. E.
,
2004
, “
An Investigation of the Relationship Between Measured Intake Temperature, BDC Temperature, and Combustion Phasing for Premixed and DI HCCI Engines
,”
SAE
Paper No. 2004-01-1900.
19.
Mendrea
,
B.
,
Chang
,
Y.
,
Akkus
,
Y. Z. A.
,
Sterniak
,
J.
, and
Bohac
,
S. V.
,
2015
, “
Investigations of the Effect of Ambient Condition on SACI Combustion Range
,”
SAE
Paper No. 2015-01-0828.
20.
Gamma Technologies
,
2015
, “
GT-SUITE: A Revolutionary MBSE Tool
,”
Gamma Technologies, Inc.
, Westmont, IL.
21.
Woschni
,
G. A.
,
1967
, “
Universally Applicable Equation for the Instantaneous Heat Transfer Coefficient in the Internal Combustion Engine
,”
SAE
Paper No. 670931.
22.
Persson
,
H.
,
Hultqvist
,
A.
,
Johansson
,
B.
, and
Remón
,
A.
,
2007
, “
Investigation of the Early Flame Development in Spark Assisted HCCI Combustion Using High Speed Chemiluminescence Imaging
,”
SAE
Paper No. 2007-01-0212.
23.
Ortiz-Soto
,
E. A.
,
Lavoie
,
G. A.
,
Martz
,
J. B.
,
Wooldridge
,
M. S.
, and
Assanis
,
D. N.
,
2014
, “
Enhanced Heat Release Analysis for Advanced Multi-Mode Combustion Engine Experiments
,”
Appl. Energy
,
136
, pp.
465
479
.
You do not currently have access to this content.