Use of Detailed Chemical Kinetics to Study HCCI Engine Combustion With Consideration of Turbulent Mixing Effects

2002 ◽  
Vol 124 (3) ◽  
pp. 702-707 ◽  
Author(s):  
S.-C. Kong ◽  
R. D. Reitz
Keyword(s):  
Chemical Kinetics ◽  
Turbulent Mixing ◽  
Combustion Process ◽  
Reaction Rates ◽  
Detailed Chemical Kinetics ◽  
Wide Range ◽  
Hcci Engines ◽  
Heavy Duty Diesel ◽  
Flame Chemistry ◽  
Detailed Chemical

Detailed chemical kinetics was used in an engine CFD code to study the combustion process in HCCI engines. The CHEMKIN code was implemented in KIVA such that the chemistry and flow solutions were coupled. The reaction mechanism consists of hundreds of reactions and species and is derived from fundamental flame chemistry. Effects of turbulent mixing on the reaction rates were also considered. The results show that the present KIVA/CHEMKIN model is able to simulate the ignition and combustion process in three different HCCI engines including a CFR engine and two modified heavy-duty diesel engines. Ignition timings were predicted correctly over a wide range of engine conditions without the need to adjust any kinetic constants. However, it was found that the use of chemical kinetics alone was not sufficient to accurately simulate the overall combustion rate. The effects of turbulent mixing on the reaction rates need to be considered to correctly simulate the combustion and heat release rates.

Modeling Direct-Injection Gasoline HCCI Combustion Using Detailed Chemistry and CFD

2001 ◽  
Author(s):  
Song-Charng Kong ◽  
Rolf D. Reitz
Keyword(s):  
Turbulent Mixing ◽  
Direct Injection ◽  
Combustion Process ◽  
Reaction Rates ◽  
Injection Timing ◽  
Detailed Chemical Kinetics ◽  
Detailed Chemistry ◽  
Hcci Combustion ◽  
Wide Range ◽  
Hcci Engines

Abstract Detailed chemical kinetics was implemented into an engine CFD code to study the combustion process in Homogeneous Charge Compression Ignition (HCCI) engines. The CHEMKIN code was implemented into KIVA-3V such that the chemistry and flow solutions were coupled. Effects of turbulent mixing on the reaction rates were also considered. The model was validated using experimental data from a direct-injection Caterpillar engine operated in the HCCI mode using gasoline. The results show that good levels of agreement were obtained using the present KIVA/CHEMKIN model for a wide range of engine conditions including various injection timings, engine speeds, and loads. It was found that the effects of turbulent mixing on the reaction rates needed to be considered to correctly simulate the combustion phasing. It was also found that the presence of residual radicals could enhance the mixture reactivity and hence shorten the ignition delay time. The NOx emissions were found to increase as the injection timing was retarded, in agreement with experimental results.

The Combustion of Lean Mixtures of Methane and Air—A Kinetic Investigation

1986 ◽  
Vol 108 (4) ◽  
pp. 336-342 ◽  
Author(s):  
M. Hanna ◽  
G. A. Karim
Keyword(s):  
Combustion Process ◽  
Kinetic Scheme ◽  
Reaction Rates ◽  
Chemical Kinetic ◽  
Energy Utilization ◽  
Wide Range ◽  
Lean Mixtures ◽  
The Times ◽  
Combustion Processes ◽  
Detailed Chemical

The combustion of lean mixtures of methane, representing natural gas, in air is examined analytically employing a detailed chemical kinetic scheme involving 14 species and made up of 32 reaction steps that proceed simultaneously. The changes with time in the concentrations of the major relevant reactive species are determined throughout, right from the commencement of the preignition reactions to the time of achieving near equilibrium conditions. The results of such an approach to the combustion process are considered over a wide range of temperature (1200 K–2200 K) and equivalence ratios (from 0.20 to the stoichiometric value). Information is then presented in relation to some important combustion parameters that included the ignition delay, overall reaction rates and the times needed for completing the combustion process. Some guidelines are suggested for effecting eventually improved energy utilization and reduced environmental pollution from combustion processes involving lean mixtures of methane and air.

A Simulation of the Combustion of N-Heptane Fueled HCCI Engines Using a 3-D Model With Detailed Chemical Kinetics

2005 ◽  
Author(s):  
Chengke Liu ◽  
Ghazi A. Karim
Keyword(s):  
Carbon Monoxide ◽  
Combustion Chamber ◽  
Chemical Kinetics ◽  
Combustion Process ◽  
Combustion Characteristics ◽  
Chamber Wall ◽  
Detailed Chemical Kinetics ◽  
Hcci Engine ◽  
Initial Location ◽  
Detailed Chemical

A CFD multi-dimensional computational approach has been developed through a combination of a modified KIVA3 code together with a detailed chemical kinetics scheme for the oxidation of n-heptane in air while considering the effects of turbulence. The effects of adding different quantities of hydrogen, methane and carbon monoxide to the heptane on the combustion characteristics of the HCCI engine under different conditions were investigated both experimentally and numerically. The effects of changes in the combustion chamber wall surface temperature on the combustion characteristics of the HCCI engine were examined. It was found that the presence with n-heptane of some hydrogen, methane or carbon monoxide could delay to various extents the autoignition, while changes in the values of the combustion chamber wall temperature influence the autoignition timing and its initial location. It is suggested that the supplementing of the liquid fuel with gaseous fuels and/or application of a suitable glow-plug surface of optimum size and location fitted with temperature control may aid in controlling the combustion process of an HCCI engine while obtaining higher power output without producing knock.

Numerical CFD evaluation of a flameless burner using detailed chemical kinetics

2017 ◽  
Author(s):  
Marco Antonio Nascimento ◽  
Lucilene Oliveria Rodrigues ◽  
Fagner Luis Goulart Dias
Keyword(s):  
Chemical Kinetics ◽  
Detailed Chemical Kinetics ◽  
Flameless Burner ◽  
Detailed Chemical

PARALLEL SOLVER FOR THE SIMULATIONS OF DETONATION WAVES ON UNSTRUCTURED GRIDS

2020 ◽  
Author(s):  
A. I. Lopato ◽  
◽  
A. G. Eremenko ◽  
Keyword(s):  
Chemical Kinetics ◽  
Numerical Scheme ◽  
Unstructured Grids ◽  
Numerical Study ◽  
Numerical Approach ◽  
Detonation Waves ◽  
Detailed Chemical Kinetics ◽  
Parallel Solver ◽  
Further Development ◽  
Detailed Chemical

Recently, we developed a numerical approach for the simulation of detonation waves on fully unstructured grids and applied it to the numerical study of the mechanisms of detonation initiation in multifocusing systems. Current work is devoted to further development of our numerical approach, namely, parallelization of the numerical scheme and introduction of more comprehensive detailed chemical kinetics scheme.

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