Simulation of liquefied petroleum gas jet in combustion chamber of spark ignition engine

Based on the mathematical validated by experimental data, the present paper introduces the evolution of concentration and velocity fields of Liquefield Petroleum Gas (LPG) jet in combustion chamber of spark ingnition enegine under effects of injection conditions and surrounding environment. The results allow us to predict the development of jet for an efficient organization of mixture preparation and combustion process in LPG direct injection spark ignition engine

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LES study on mixing and combustion in a Direct Injection Spark Ignition engine

Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles ◽

10.2516/ogst/2018028 ◽

2018 ◽

Vol 73 ◽

pp. 32

Author(s):

Nicolas Iafrate ◽

Anthony Robert ◽

Jean-Baptiste Michel ◽

Olivier Colin ◽

Benedicte Cuenot ◽

...

Keyword(s):

Ignition Time ◽

Direct Injection ◽

Combustion Process ◽

Spark Ignition ◽

Spark Ignition Engine ◽

Pollutant Emissions ◽

Spark Ignition Engines ◽

Eddy Simulation ◽

Mixture Preparation ◽

The Impact

Downsized spark ignition engines coupled with a direct injection strategy are more and more attractive for car manufacturers in order to reduce pollutant emissions and increase efficiency. However, the combustion process may be affected by local heterogeneities caused by the interaction between the spray and turbulence. The aim for car manufacturers of such engine strategy is to create, for mid-to-high speeds and mid-up-high loads, a mixture which is as homogeneous as possible. However, although injection occurs during the intake phase, which favors homogeneous mixing, local heterogeneities of the equivalence ratio are still observed at the ignition time. The analysis of the mixture preparation is difficult to perform experimentally because of limited optical accesses. In this context, numerical simulation, and in particular Large Eddy Simulation (LES) are complementary tools for the understanding and analysis of unsteady phenomena. The paper presents the LES study of the impact of direct injection on the mixture preparation and combustion in a spark ignition engine. Numerical simulations are validated by comparing LES results with experimental data previously obtained at IFPEN. Two main analyses are performed. The first one focuses on the fuel mixing and the second one concerns the effect of the liquid phase on the combustion process. To highlight these phenomena, simulations with and without liquid injection are performed and compared.

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Potential of alcohol fuels in active and passive pre-chamber applications in a passenger car spark-ignition engine

International Journal of Engine Research ◽

10.1177/14680874211053168 ◽

2021 ◽

pp. 146808742110531

Author(s):

Patrick Burkardt ◽

Christian Wouters ◽

Stefan Pischinger

Keyword(s):

Combustion Chamber ◽

Alternative Fuels ◽

Direct Injection ◽

Combustion Process ◽

Spark Ignition ◽

Spark Ignition Engine ◽

Passenger Car ◽

Excess Air ◽

Lean Limit ◽

Alcohol Fuels

Both the shift from fossil to alternative fuels and the implementation of a pre-chamber combustion system allow for an increase in the efficiency of an internal combustion engine through optimizing its combustion process, while simultaneously reducing the engine-out emissions. The combination of alcohol-based fuels and pre-chamber combustion concepts has not been investigated on spark-ignition engines with high compression ratios in a passenger car size. This study presents investigations to show the potential in maximum achievable lean limit and net indicated efficiency. In particular, we present investigations of two alternative alcohol fuels on a direct-injection spark-ignition single-cylinder research engine for passenger car applications with a compression ratio of 16.4. The engine was operated with both an active and a passive pre-chamber, and the experimental results were compared to those of conventional spark-ignition operation. Direct injection was used for both the main combustion chamber and the pre-chamber. Methanol and ethanol were used as fuels for the main combustion chamber, whereas exclusively ethanol was used for the pre-chamber fueling. The performance of the alcohol fuels in all combustion configurations was evaluated in both part-load and high-load conditions. In particular, investigations of the combustion behavior over a variation of the excess air ratio at indicated mean effective pressures of 6 and 15 bar were performed. It can be concluded that with the use of methanol as fuel for the main combustion chamber, both higher excess air ratios and higher indicated efficiencies were achieved compared to the use of ethanol as the main combustion chamber fuel. In particular, a maximum net indicated efficiency of 48% at an excess air ratio of 2.0 was achieved with methanol. Moreover, active pre-chamber operation extended the lean limit to an excess air ratio of 2.3 compared to the maximum lean limit of 1.7 in passive pre-chamber operation.

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