Numerical study of premixed HCCI engine combustion and its sensitivity to computational mesh and model uncertainties

This study used a numerical model to investigate the combustion process in a premixed iso-octane homogeneous charge compression ignition (HCCI) engine. The engine was a supercharged Cummins C engine operated under HCCI conditions. The CHEMKIN code was implemented into an updated KIVA-3V code so that the combustion could be modelled using detailed chemistry in the context of engine CFD simulations. The model was able to accurately simulate the ignition timing and combustion phasing for various engine conditions. The unburned hydrocarbon emissions were also well predicted while the carbon monoxide emissions were under predicted. Model results showed that the majority of unburned hydrocarbon is located in the piston-ring crevice region and the carbon monoxide resides in the vicinity of the cylinder walls. A sensitivity study of the computational grid resolution indicated that the combustion predictions were relatively insensitive to the grid density. However, the piston-ring crevice region needed to be simulated with high resolution to obtain accurate emissions predictions. The model results also indicated that HCCI combustion and emissions are very sensitive to the initial mixture temperature. The computations also show that the carbon monoxide emissions prediction can be significantly improved by modifying a key oxidation reaction rate constant.

[1]  John E. Dec,et al.  A Computational Study of the Effects of Low Fuel Loading and EGR on Heat Release Rates and Combustion Limits in HCCI Engines , 2002 .

[2]  R. Reitz,et al.  Turbulence Modeling of Internal Combustion Engines Using RNG κ-ε Models , 1995 .

[3]  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 .

[4]  Charles K. Westbrook,et al.  Chemical kinetics of hydrocarbon ignition in practical combustion systems , 2000 .

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

[6]  Rolf D. Reitz,et al.  The Influence of Physical Input Parameter Uncertainties on Multidimensional Model Predictions of Diesel Engine Performance and Emissions , 2000 .

[7]  Song-Charng Kong,et al.  Investigation of Hydrocarbon Emissions from a Direct Injection-Gasoline Premixed Charge Compression Ignited Engine , 2002 .

[8]  Rolf D. Reitz,et al.  MODELING THE EFFECT OF EGR AND MULTIPLE INJECTION SCHEMES ON I. C. ENGINE COMPONENT TEMPERATURES , 2000 .

[9]  R. Reitz,et al.  Modeling and Experiments of HCCI Engine Combustion Using Detailed Chemical Kinetics with Multidimensional CFD , 2001 .

[10]  Bengt Johansson,et al.  Influence of Mixture Quality on Homogeneous Charge Compression Ignition , 1998 .

[11]  R. Reitz,et al.  A temperature wall function formulation for variable-density turbulent flows with application to engine convective heat transfer modeling , 1997 .

[12]  R. J. Kee,et al.  Chemkin-II : A Fortran Chemical Kinetics Package for the Analysis of Gas Phase Chemical Kinetics , 1991 .

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

[14]  A. A. Amsden,et al.  KIVA-3V: A Block-Structured KIVA Program for Engines with Vertical or Canted Valves , 1997 .

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

[16]  Rudolf H. Stanglmaier,et al.  Homogeneous charge compression ignition (HCCI): Benefits, compromises, and future engine applications , 1999 .

[17]  Song-Charng Kong,et al.  Application of detailed chemistry and CFD for predicting direct injection HCCI engine combustion and emissions , 2002 .

[18]  D. Foster,et al.  Compression-Ignited Homogeneous Charge Combustion , 1983 .

[19]  R. Reitz,et al.  Use of Detailed Chemical Kinetics to Study HCCI Engine Combustion With Consideration of Turbulent Mixing Effects , 2002 .

[20]  Bengt Johansson,et al.  Optical Diagnostics Applied to a Naturally Aspirated Homogeneous Charge Compression Ignition Engine , 1999 .