A chemical kinetics based investigation on laminar burning velocity and knock occurrence in a spark-ignition engine fueled with ethanol–water blends

Fuel ◽  
2020 ◽  
Vol 280 ◽  
pp. 118587
Author(s):  
J.L.S. Fagundez ◽  
R.L. Sari ◽  
A. Garcia ◽  
F.M. Pereira ◽  
M.E.S. Martins ◽  
...  
Keyword(s):  
Chemical Kinetics ◽  
Burning Velocity ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Laminar Burning Velocity

A Laminar Burning Velocity Correlation for Hydrogen/Air Mixtures Valid at Spark-Ignition Engine Conditions

2003 ◽  
Author(s):  
Sebastian Verhelst ◽  
Roger Sierens
Keyword(s):  
Chemical Kinetics ◽  
Laminar Flame ◽  
Burning Velocity ◽  
Spark Ignition ◽  
Flame Speed ◽  
Spark Ignition Engine ◽  
Laminar Flame Speed ◽  
Spark Ignition Engines ◽  
Laminar Burning Velocity ◽  
Velocity Correlation

During the development of a quasi-dimensional simulation programme for the combustion of hydrogen in spark-ignition engines, the lack of a suitable laminar flame speed formula for hydrogen/air mixtures became apparent. A literature survey shows that none of the existing correlations covers the entire temperature, pressure and mixture composition range as encountered in spark-ignition engines. Moreover, there is ambiguity concerning the pressure dependence of the laminar burning velocity of hydrogen/air mixtures. Finally, no data exists on the influence of residual gases. This paper looks at several reaction mechanisms found in the literature for the kinetics of hydrogen/oxygen mixtures, after which one is selected that corresponds best with available experimental data. An extensive set of simulations with a one-dimensional chemical kinetics code is performed to calculate the laminar flame speed of hydrogen/air mixtures, in a wide range of mixture compositions and initial pressures and temperatures. The use of a chemical kinetics code permits the calculation of any desired set of conditions and enables the estimation of interactions, e.g. between pressure and temperature effects. Finally, a laminar burning velocity correlation is presented, valid for air-to-fuel equivalence ratios λ between 1 and 3 (fuel-to-air equivalence ratio 0.33 < φ < 1), initial pressures between 1 bar and 16 bar, initial temperatures between 300 K and 800 K and residual gas fractions up to 30 vol%. These conditions are sufficient to cover the entire operating range of hydrogen fuelled spark-ignition engines.

Modeling laminar burning velocity of gasoline using an energy fraction-based mixing rule approach

2018 ◽  
Vol 233 (5) ◽  
pp. 1245-1258 ◽  
Author(s):  
Joohan Kim ◽  
Kyoungdoug Min
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Burning Velocity ◽  
Direct Injection ◽  
Velocity Model ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Mixing Rule ◽  
Laminar Burning Velocity ◽  
Direct Injection Spark Ignition

To determine an optimum combustion chamber design and engine operating strategies, computational fluid dynamics simulations of direct-injection spark-ignition engines have become an indispensable step in the powertrain development process. The laminar burning velocity of gasoline is known as an essential input parameter for combustion simulations. In this study, a new methodology for modeling the laminar burning velocity of gasoline for direct-injection spark-ignition engine simulations is proposed. Considering the gasoline as a complex mixture of hydrocarbon fuel, three hydrocarbons, iso-octane, n-heptane, and toluene were incorporated as surrogate fuel components to represent gasoline with distinct aromatic laminar flame characteristics compared to alkane. A mixing rule, based on energy fractions, was adopted to consider the compositional variation of gasoline. The laminar burning velocities of iso-octane, n-heptane, and toluene were calculated under wide thermo-chemical conditions in conjunction with detailed chemical reaction kinetics in the premixed flame simulation. Finally, a set of laminar burning velocity model equations was derived by curve-fitting the flame simulation results of each hydrocarbon component in consideration of the effect of temperature, pressure, and diluent. The laminar burning velocity model was validated against the measurement data of gasoline’s laminar burning velocity found in the literature, and was applied to the computational fluid dynamics simulation of a direct-injection spark-ignition engine under the various operating conditions to explore the prediction capability.

scholarly journals A laminar burning velocity and flame thickness correlation for ethanol–air mixtures valid at spark-ignition engine conditions

Fuel ◽  
2012 ◽  
Vol 102 ◽  
pp. 460-469 ◽  
Author(s):  
J. Vancoillie ◽  
J. Demuynck ◽  
J. Galle ◽  
S. Verhelst ◽  
J.A. van Oijen
Keyword(s):  
Burning Velocity ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Laminar Burning Velocity ◽  
Flame Thickness

Comparison of Burning Rates in a Natural-Gas-Fueled Spark Ignition Engine

1985 ◽  
Vol 107 (4) ◽  
pp. 908-913 ◽  
Author(s):  
A. L. Jones ◽  
R. L. Evans
Keyword(s):  
Natural Gas ◽  
Burning Velocity ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Laminar Burning Velocity ◽  
Crank Angle ◽  
Turbulence Effects ◽  
Release Analysis ◽  
Burning Rates ◽  
Ignition Delay Period

A series of tests was conducted on a Toyota, four-cylinder, spark ignition engine which was modified to run on either gasoline or natural gas. The aim of the experiment was to investigate the performance and combustion behavior of natural gas, with particular emphasis on its low burning velocity. A pressure transducer installed in the cylinder head was used to obtain pressure versus crank angle curves from which mass burn rates and burning velocities were calculated, using a heat release analysis program. Results indicate that the low laminar burning velocity of natural gas extends its ignition delay period (time to 1 percent burned) by up to 100 percent compared with gasoline. This contrasts with the remainder of the combustion period which is dominated by turbulence effects that produce very similar burning velocities for the two fuels.

scholarly journals Combustion Modelling to Evaluate Turbulent Burning Velocities During Spark Ignition Engine Combustion

1991 ◽  
Author(s):  
E. H. James
Keyword(s):  
Combustion Chamber ◽  
Computer Model ◽  
Burning Velocity ◽  
Exhaust Emissions ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Unknown Quantity ◽  
Engine Combustion ◽  
Pattern Development ◽  
Turbulent Burning Velocity

Abstract “Phenomenological” computer models of the spark ignition engine combustion process are predominantly used in a “predictive” mode i.e. the modeller develops the computer program by utilising the best current understanding of phenomena associated with the process. Thus, suitable expressions are incorporated to depict turbulent burning velocity, heat exchange with the surroundings, flame pattern development, exhaust emissions etc.. The accuracy of the model is then tested by subsequent comparison with pertinent “global” engine performance parameters such as pressure-time diagrams, average flame speeds and exhaust emissions. The “predictiveness” of the model arises from the inclusion of the turbulent burning velocity expression and assumed flame pattern development. These are notoriously difficult to specify precisely and resort is often made to generalised approximations. Thus, turbulent burning velocity is frequently accounted for by the use of expressions developed from experiments on dissimilar engine designs or even “out-of-engine” flames. Accurate flame pattern development is an equally unknown quantity since it is influenced by turbulence and swirl levels, combustion chamber surface temperatures and design, mixture homogeneity etc.. These difficulties are invariably overcome by subsuming them in a general inaccurate assumption that the flame development is spherical in nature and centred at the spark plug. Even though the “global” computer model predictions may be acceptably accurate with such assumptions, it is highly unlikely that the detailed flame progression across the chamber is modelled correctly. To overcome such criticisms, the computer model can be used in a different operational mode (1) with the ultimate aim of more precise specifications of turbulent burning velocity and how it varies across the combustion chamber.

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