Investigating the importance of mass transfer on the formation of HCCI engine emissions using a multi-zone model

The focus of the present study is to investigate the importance of mass transfer on the formation of the most important HCCI engine emissions, i.e. unburned HC and CO emissions. A multi-zone model is used for this purpose. The multi-zone model includes sub-models for the heat transfer between zones and to the cylinder wall and for the mass transfer between the hotter and colder regions of the combustion chamber. The combustion mechanism is modeled using a reduced set of chemical reactions coupled with a chemical kinetics solver. The results indicate that mass transfer during combustion and expansion plays a significant role on the formation of both the unburned HC and the CO emissions and therefore must be taken into account for the closed part of the engine cycle, i.e. compression, combustion and expansion. According to the model results, the formation of these emissions is located mainly at the crevice and the near-the-wall regions and is determined by the temperature field and mass transfer. It is shown that neglecting mass transfer in these regions during combustion and expansion would result to a significant deviation from the values predicted with the inclusion of mass transfer.

[1]  Rolf D. Reitz,et al.  Assessment of Wall Heat Transfer Models for Premixed-Charge Engine Combustion Computations , 1991 .

[2]  Jing-Tang Yang,et al.  Approximate Solution—One-Dimensional Energy Equation for Transient, Compressible, Low Mach Number Turbulent Boundary Layer Flows , 1989 .

[3]  Alex C. Alkidas,et al.  Combustion advancements in gasoline engines , 2007 .

[4]  P. Lettieri,et al.  An introduction to heat transfer , 2007 .

[5]  Song-Charng Kong,et al.  Modeling Combustion in Compression Ignition Homogeneous Charge Engines , 1992 .

[6]  Bengt Johansson,et al.  Reacting Boundary Layers in Homogeneous Charge Compression Ignition (HCCI) Engine , 2001 .

[7]  John B. Heywood,et al.  Internal combustion engine fundamentals , 1988 .

[8]  Dimitrios T. Hountalas,et al.  Description of in-Cylinder Combustion Processes in HCCI Engines Using a Multi-Zone Model , 2005 .

[9]  G. A. Lavoie,et al.  Modeling of HCCI Combustion and Emissions Using Detailed Chemistry , 2001 .

[10]  Valeri Golovitchev,et al.  Gasoline HCCI Modeling: An Engine Cycle Simulation Code with a Multi-Zone Combustion Model , 2002 .

[11]  N. P. Komninos,et al.  Development of a New Multi-Zone Model for the Description of Physical Processes in HCCI Engines , 2004 .

[12]  Dimitrios T. Hountalas,et al.  A parametric investigation of hydrogen hcci combustion using a multi-zone model approach , 2007 .

[13]  Bengt Johansson,et al.  A Study of the Homogeneous Charge Compression Ignition Combustion Process by Chemiluminescence Imaging , 1999 .

[14]  Robert W. Dibble,et al.  A Multi-Zone Model for Prediction of HCCI Combustion and Emissions , 2000 .

[15]  Robert W. Dibble,et al.  Effect of Mixing on Hydrocarbon and Carbon Monoxide Emissions Prediction for Isooctane HCCI Engine Combustion Using a Multi-zone Detailed Kinetics Solver , 2003 .

[16]  Steve Richardson,et al.  Modelling of HCCI Engines: Comparison of Single-zone, Multi-zone and Test Data , 2005 .

[17]  M. Jia,et al.  A Comparative Study of Multi-zone Combustion Models for HCCI Engines , 2008 .

[18]  W. J. D. Annand,et al.  Heat Transfer in the Cylinders of Reciprocating Internal Combustion Engines , 1963 .

[19]  M. David Checkel,et al.  Novel Method of Setting Initial Conditions for Multi-Zone HCCI Combustion Modeling , 2007 .

[20]  Fabian Mauss,et al.  NOx and N2O formation in HCCI engines , 2005 .

[21]  Scott B. Fiveland,et al.  Development of a Two-Zone HCCI Combustion Model Accounting for Boundary Layer Effects , 2001 .

[22]  Bengt Johansson,et al.  Homogeneous Charge Compression Ignition (HCCI) Using Isooctane, Ethanol and Natural Gas - A Comparison with Spark Ignition Operation , 1997 .

[23]  M. D. Checkel,et al.  Investigating the Effects of Reformed Fuel Blending in a Methane- or n-Heptane-HCCI Engine Using a Multi-Zone Model , 2007 .

[24]  Robert W. Dibble,et al.  A Decoupled Model of Detailed Fluid Mechanics Followed by Detailed Chemical Kinetics for Prediction of Iso-Octane HCCI Combustion , 2001 .

[25]  Stanislaw E. Golunski,et al.  Use of catalytic reforming to aid natural gas HCCI combustion in engines: experimental and modelling results of open-loop fuel reforming , 2005 .

[26]  Fabian Mauss,et al.  Supercharged Homogeneous Charge Compression Ignition , 1998 .

[27]  Fabian Mauss,et al.  Sources of CO emissions in an HCCI engine: A numerical analysis , 2006 .

[28]  Seref Soylu.  Examination of combustion characteristics and phasing strategies of a natural gas HCCI engine , 2005 .

[29]  Ming Jia,et al.  Numerical simulation of homogeneous charge compression ignition combustion using a multi-dimensional model , 2007 .