This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Reducing Pressure Fluctuations at High Loads by Means of Charge Stratification in HCCI Combustion with Negative Valve Overlap
ISSN: 0148-7191, e-ISSN: 2688-3627
Published June 15, 2009 by SAE International in United States
Annotation ability available
Future demands for improvements in the fuel economy of gasoline passenger car engines will require the development and implementation of advanced combustion strategies, to replace, or combine with the conventional spark ignition strategy. One possible strategy is homogeneous charge compression ignition (HCCI) achieved using negative valve overlap (NVO). However, several issues need to be addressed before this combustion strategy can be fully implemented in a production vehicle, one being to increase the upper load limit. One constraint at high loads is the combustion becoming too rapid, leading to excessive pressure-rise rates and large pressure fluctuations (ringing), causing noise.
In this work, efforts were made to reduce these pressure fluctuations by using a late injection during the later part of the compression. A more appropriate acronym than HCCI for such combustion is SCCI (Stratified Charge Compression Ignition). The approach was evaluated in tests with a single-cylinder metal research engine and a single-cylinder optical engine. The latter was used to characterize the combustion in laser-based analyses including laser-induced florescence (LIF) determinations of fuel tracer, OH and CH2O (formaldehyde) distributions. A high speed camera was also used for direct imaging of chemiluminescence.
The effects of two main parameters were studied: the proportion of fuel injected late to create a stratified charge and the timing of the late injection. In addition, two fuels were used: a certification gasoline fuel and a blend of n-heptane, iso-octane and 3-pentanone. Both fuels were used in the metal engine for comparison. Use of a stratified charge allowed the maximum pressure-rise rates and ringing intensity to be reduced at the expense of increases in NOx and CO emissions, regardless of fuel type. Optical results indicated that both the fuel distribution and combustion were not homogenous.
CitationDahl, D., Andersson, M., Berntsson, A., Denbratt, I. et al., "Reducing Pressure Fluctuations at High Loads by Means of Charge Stratification in HCCI Combustion with Negative Valve Overlap," SAE Technical Paper 2009-01-1785, 2009, https://doi.org/10.4271/2009-01-1785.
- The European Automobile Manufacturers Association http://www.acea.be 2009
- European Federation for Transport and Environment http://www.transportenvironment.org/Article185.html 2006
- Heywood, J. B. Internal Combustion engine fundamentals Singapore Macgraw-Hill Book Company 1988
- Willand, J. Niederding, R-G. Vent, G. Enderle, C. “The Knocking Syndrome - Its cure and Its Potential” SAE Technical Paper Series, SAE paper 982483 1998
- Denbratt, I. “Method of controlling the process of combustion in an internal combustion engine with means for controlling the engine valves” Volvo Car Corporation 1998
- Koopmans, L. Denbratt, I. “A Four Stroke Camless Engine, Operated in Homogeneous Charge Compression Ignition Mode with Commercial Gasoline” SAE Technical Paper Series, SAE paper 2001-01-3610 2001
- Koopmans, L. Ogink, R. Denbratt, I. “Direct Gasoline Injection in the Negative Valve Overlap of a Homogeneous Charge Compression Ignition Engine” JSAE SAE Technical Paper Series, JSAE paper 20030195, SAE Paper 2003-01-1854 2003
- Dahl, D. Denbratt, I. Koopmans, L. “An Evaluation of Different Combustion Strategies for SI Engines in a Multi-Mode Combustion Engine” SAE Technical Paper Series, SAE paper 2008-01-0426 2008
- Eng, J.A. “Characterization of Pressure Waves in HCCI Combustion” SAE Technical Paper Series, SAE Paper 2002-01-2859
- Burgdorf, K. Denbratt, I. “Cylinder Pressure Based Knock Detection Methods” SAE Technical Paper Series, SAE paper 972932 1997
- Amano, T. Morimoto, S. Kawabata, Y. “Modeling of the Effect of Air/Fuel Ratio and Temperature Distribution on HCCI Engines” SAE Technical Paper Series, SAE Paper 2001-01-1024 2001
- Sjöberg, M. Edling, L.-O. Eliassen, T. Magnusson, L. Ångström, H.-E. “GDI HCCI: Effects of Injection Timing and Air Swirl on Fuel Stratification, Combustion and Emissions Formation” SAE Technical Paper Series, SAE Paper 2002-01-0106 2002
- Marriot, C.D. Reitz, R.D. “Experimental Investigation of Direct Injection-Gasoline for Premixed Compression Ignited Combustion Phasing Control” SAE Technical Paper Series, SAE Paper 2002-01-0418 2002
- Girard, J.W. Dibble, R.W. Flowers, D.L Aceves, S.A “An Investigation of the Effect of Fuel-Air Mixedness on the Emissions from an HCCI Engine” SAE Technical Paper Series, SAE Paper 2002-01-1758
- Urushihara, T. Hiraya, K. Kakuhou, A. Itoh, T. “Expansion of HCCI Operating Region by the Combination of Direct Fuel Injection, Negative Valve Overlap and Internal Fuel Reformation” SAE Paper 2003-01-0749 2003
- Dec, J.E. Sjöberg, M. “Isolating the Effects of Fuel Chemistry on Combustion Phasing in an HCCI Engine and the Potential of Fuel Stratification for Ignition Control” SAE Technical Paper Series, SAE Paper 2004-01-0557 2004
- Aroonsrisopon, T. Werner, P. Waldman, J.O. Sohm, V. Foster, D.E. Morikawa, T. Iida, M. “Expanding the HCCI Operation With the Charge Stratification” SAE Technical Paper Series, SAE Paper 2004-01-1756 2004
- Standing, R. Kalian, N. Ma, T. Zhao, H. Wirth, M. Schamel, A. “Effects of Injection Timing and Valve Timings on CAI Operation in a Multi-Cylinder DI Gasoline Engine” SAE Technical Paper Series, SAE Paper 2005-01-0132 2005
- Leach, B. Zhao, H. Li, Y. Ma, T. “Control of CAI Combustion Through Injection Timing in a GDI Engine With an Air-Assisted Injector” SAE Technical Paper Series, SAE Paper 2005-0134 2005
- Wang, Z. Wang, J.-X. Shuai, A.-J. Ma, Q.-J. “Effects of Spark Ignition and Stratified Charge on Gasoline HCCI Combustion With Direct Injection” SAE Technical Paper Series, SAE Paper 2005-01-0137 2005
- Thirouard, B. Cherel, J. Knop, V. “Investigation of Mixture Quality Effect on CAI Combustion” SAE Technical Paper Series, SAE Paper 2005-01-0141 2005
- Ozaki, J. Iida, N. “Effect of Degree of Unmixedness on HCCI Combustion Based on Experiment and Numerical Analysis” SAE Technical Paper Series, SAE Paper 2006-32-0046 2006
- Li, Y. Zhao, H. Brouzos, N. Ma, T. Leach, B. “Effect of Injection Timing on Mixture and CAI Combustion in a GDI Engine with an Air-Assisted Injector” SAE Technical Paper Series, SAE Paper 2006-01-0206 2006
- Sjöberg, M. Dec, J.E. “Smoothing HCCI Heat-Release Rates Using Partial Fuel Stratification with Two-Stage Ignition Fuels” SAE Technical Paper Series, SAE Paper 2006-01-0629 2006
- Berntsson, A.W. Denbratt, I. “HCCI Combustion Using Charge Stratification for Combustion Control” SAE Technical Paper Series, SAE Paper 2007-01-0210 2007
- Lee, C. Tomita, E. Lee, K. Characteristics of Combustion Stability and Emission in SCCI and CAI Combustion Based on Direct-Injection Gasoline Engine” SAE Technical Paper Series, SAE Paper 2007-01-1872 2007
- Herold, R.E. Foster, D.E. Ghandhi, J.B. Iverson, R.J. Eng, J.A. Najt, P.M. Fuel unmixedness effects in a gasoline homogeneous charge compression ignition engine” Int. J., Engine Res. 8 241 257 2007
- Brewster, S. Cathcart, G. Zavier, C. “The Potential of Enhanced HCCI/CAI Control Through the Application of Spray Guided Direct Injection” SAE Technical Paper Series, SAE Paper 2008-01-0035 2008
- Christensen, M. Homogeneous Charge Compression Ignition (HCCI) Engine Lund Institute of Technology 2000
- Persson, H. Sjöholm, J. Kristensson, E. Johansson, B. Richter, M. Aldén, M. “Study of Fuel Stratification on Spark Assisted Compression Ignition (SACI) Combustion with Ethanol Using High Speed Fuel PLIF SAE Technical Paper Series, SAE Paper 2008-01-2401 2008