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Journal ArticleDOI

A computational study and experiments to investigate the combustion and emission characteristics of a small naturally aspirated diesel engine through changes in combustion chamber geometry, injection parameters and EGR

01 Aug 2020-Vol. 912, Iss: 4, pp 042031
About: The article was published on 2020-08-01 and is currently open access. It has received 2 citations till now. The article focuses on the topics: Naturally aspirated engine & Combustion chamber.
Citations
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Journal ArticleDOI
TL;DR: In this paper , the shape of the combustion chamber of a two-cylinder diesel engine with high-pressure common rail direct injection (CRDI) system was determined by comparing the fuel economy and soot emission of diesel engines.

1 citations

Journal ArticleDOI
TL;DR: In this paper , a 3-dimentional transient model of in-cylinder flow and combustion process is established by the Forte platform, and the engine test system is set up.
Abstract: Heavy-fuel aviation piston engines (HF-APEs) are widely used in general aviation and unmanned aerial vehicle (UAV) due to their safety and fuel economy. This paper describes a numerical and experimental study of scavenging and combustion processes on a 2-Stroke Direct Injected HF-APEs for light aircraft, with its cylinder specifically designed as cross scavenging. A 3-Dimentional transient model of in-cylinder flow and combustion process is established by the Forte platform, and the engine test system is set up. By comparing the simulation results to the experimental results, it showed that multi-ports cross scavenging can generate unbalanced aerodynamic torque in the cylinder. In the compression process, the swirl ratio (SR) gradually increases, and the peak SR reaches 15. Moreover, approximately 25% of exhaust residual gas in the cylinder is conducive to the fuel atomization and evaporation process in a high-altitude environment. When the injection timing is between −8 °CA and −16 °CA, the engine has the optimal power and economy performance at different altitudes. Finally, when the injection advance angle moves forward by 4 °CA, the maximum pressure increases by 2 MPa, with the rising rate decreasing gradually. The results have important significance for the development of the combustion system of small 2-Stroke Direct Injected HF-APEs.
References
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Proceedings ArticleDOI
TL;DR: In this paper, the effects of temperature T and equivalence ratio Φ on soot formation at high pressures up to 5 MPa were investigated in a diesel engine and the trajectory in relation to both soot and NO formation region gives suggestion of a possibility of high temperature mixture combustion to reduce particulate formation in diesel engines.
Abstract: Experiments on the effects of temperature T and equivalence ratio Φ on soot formation at high pressures up to 5 MPa were conducted. Discussion of the trajectory in relation to both soot and NO formation region gives suggestion of a possibility of high temperature ― rich mixture combustion to reduce particulate formation in diesel engines

289 citations

Journal ArticleDOI
Gautam Kalghatgi1
TL;DR: In this article, the authors proposed that high antiknock quality fuels, those with high research octane number and preferably low motor octane numbers, will enable future spark-ignition engines to reach their full potential.
Abstract: The demand for transport energy is increasing, but this increase is heavily skewed toward heavier fuels such as diesel and jet fuel while the demand for gasoline might decrease. As spark-ignition engines develop to become more efficient, abnormal combustion such as knock and preignition will become more likely. High antiknock quality fuels, those with high research octane number and preferably low motor octane number, will enable future spark-ignition engines to reach their full potential. Higher fuel antiknock quality is also likely to mitigate “superknock” resulting from preignition—an abnormal combustion problem in turbocharged spark-ignition engines. In many parts of the world, fuel antiknock specifications are set on the assumption that higher motor octane number contributes to increased knock resistance. Specifications for fuel antiknock quality have a great impact on fuels manufacture and will need to be revised as this mismatch between existing specifications and engine requirements widens. The pr...

188 citations

Proceedings ArticleDOI
01 May 1996
TL;DR: In this paper, the replacement of some of the inlet air with EGR modifies the diesel combustion process and thereby affects the exhaust emissions, and the effects of oxygen replacement on ignition delay were isolated and quantified.
Abstract: This is a first of a series of papers describing how the replacement of some of the inlet air with EGR modifies the diesel combustion process and thereby affects the exhaust emissions This paper deals with only the reduction of oxygen in the inlet charge to the engine (dilution effect) The oxygen in the inlet charge to a direct injection diesel engine was progressively replaced by inert gases, whilst the engine speed, fuelling rate, injection timing, total mass and the specific heat capacity of the inlet charge were kept constant The use of inert gases for oxygen replacement, rather than carbon dioxide (CO 2) or water vapour normally found in EGR, ensured that the effects on combustion of dissociation of these species were excluded In addition, the effects of oxygen replacement on ignition delay were isolated and quantified Results from final set of tests are also presented during which the inlet charge temperature was raised progressively to quantify the effect that EGR temperature has on combustion and emissions The reduction in the inlet charge oxygen (dilution effect) resulted in very large reductions in exhaust NO x level at the expense of rises in particulates and unburnt hydrocarbon emissions The engine power output and fuel economy also deteriorated substantially Raising the inlet charge temperature increases NOx but also, substantially, the exhaust smoke and particulate emissions © 1996 Society of Automotive Engineers, Inc

186 citations

Journal ArticleDOI
TL;DR: In this paper, the effect of reentrant piston bowl geometries on pollutant emissions from a single-cylinder diesel engine was investigated. But the simulation results indicated that the selected piston bowl geometry could actually be reducing the incylinder swirl and turbulence and the emission reduction may be entirely due to the introduction of the sac-less injector.

166 citations