Effects of Gas Density and Vaporization on Penetration and Dispersion of Diesel Sprays

Naber, Jeffrey; Siebers, Dennis L.

doi:10.4271/960034

Cited by 809 publications

(769 citation statements)

References 26 publications

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“…In addition, we do not directly simulate the mixing of the injected fuel and hot air, instead using the results of mixing experiments and other modeling studies as described by Naber and Siebers 39 as follows. The start of injection takes place about 10 degrees before Top Dead Center (TDC, the point at which the piston reaches the most compressed point in its cycle) in Dec's engine 15 , so the compressed air already has a relatively high temperature and pressure.…”

Section: Modeling Approachmentioning

confidence: 99%

Chemical Kinetic Modeling Study of the Effects of Oxygenated Hydrocarbons on Soot Emissions from Diesel Engines

2006

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A detailed chemical kinetic modeling approach is used to examine the phenomenon of suppression of sooting in diesel engines by addition of oxygenated hydrocarbon species to the fuel. This suppression, which has been observed experimentally for a few years, is explained kinetically as a reduction in concentrations of soot precursors present in the hot products of a fuel-rich diesel ignition zone when oxygenates are included. Oxygenates decrease the overall equivalence ratio of the igniting mixture, producing higher ignition temperatures and more radical species to consume more soot precursor species, leading to lower soot production. The kinetic model is also used to show how different oxygenates, ester structures in particular, can have different soot-suppression efficiencies due to differences in molecular structure of the oxygenated species.4

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Section: Modeling Approachmentioning

confidence: 99%

Chemical Kinetic Modeling Study of the Effects of Oxygenated Hydrocarbons on Soot Emissions from Diesel Engines

2006

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“…For vaporizing Diesel [25], [26] but also gasoline [27] sprays, this technique shows the boundary between vaporized fuel and ambient gases because (1) refractive index differences exist between the fuel and ambient gases and (2) density gradients are created in mixture as the vaporized fuel spray cools the mixture. The good temporal resolution of this technique allows characterizing the spray even for a fast response injectors [28].…”

Section: Schlieren Imagingmentioning

confidence: 99%

Experimental characterization of diesel ignition and lift-off length using a single-hole ECN injector

Benajes

Payri

Bardi

et al. 2013

Applied Thermal Engineering

141

126

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“…Such non-reacting studies have been focused on the detailed description of quantitative spray parameters, such as vapor spray tip penetration, liquid length, or local equivalence ratio. Classical examples are those by Naber and Siebers [7], which have provided nonreacting penetration data in a wide range of gas densities (from 3.3 kg/m 3 to 58.6 kg/m 3 ) and air temperature values (from 600 to 1400K). More recent works [8] confirm that current knowledge of spray flow evolution under inert conditions is quite deep.…”

Section: Introductionmentioning

confidence: 99%

An experimental analysis on the evolution of the transient tip penetration in reacting Diesel sprays

Desantes

Pastor

García-Oliver

et al. 2014

Combustion and Flame

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Schlieren imaging has helped deeply characterize the behavior of diesel spray when injected into an oxygen-free ambient. However, when considering the transient penetration of the reacting spray after autoignition, i.e. the Diesel flame, few studies have been found in literature. Differences among optical setups as well as among experimental conditions have not allowed clear conclusions to be drawn on this issue. Furthermore, soot radiation may have a strong effect on the image quality, which cannot be neglected.The present paper reports an investigation on the transient evolution of Diesel flame based upon schlieren imaging. Experimental conditions have spanned values of injection pressure, ambient temperature and density for typical Diesel engine conditions. An optimized optical setup has been used, which makes it possible to obtain results without soot interference. Based on observations for a long injection event (4 ms Energizing Time), the analysis has resorted to extensive comparison of inert and reacting sprays parameters, which have made it possible to define different phases after autoignition.Shortly after autoignition, axial and radial expansion of the spray have been observed in terms of axial penetration and radial cone angle. After that, during a stabilization phase, the reacting spray penetrates at a similar rate as the inert one. Later, the reacting spray undergoes an acceleration period, where it penetrates at a faster rate than the inert one. Finally, the flame enters a quasi-steady penetration phase, where the ratio of reacting and inert penetration stabilizes at a nearly constant value. The duration of the reacting spray penetration stages shows modifications when varying engine parameters such as air temperature, air density, injection pressure, and nozzle diameter. However, the proportionality between reacting and inert penetration has been observed to depend mainly on temperature, in agreement with observed reductions in entrainment when shifting from inert to reacting conditions.

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Effects of Gas Density and Vaporization on Penetration and Dispersion of Diesel Sprays

Cited by 809 publications

References 26 publications

Chemical Kinetic Modeling Study of the Effects of Oxygenated Hydrocarbons on Soot Emissions from Diesel Engines

Chemical Kinetic Modeling Study of the Effects of Oxygenated Hydrocarbons on Soot Emissions from Diesel Engines

Experimental characterization of diesel ignition and lift-off length using a single-hole ECN injector

An experimental analysis on the evolution of the transient tip penetration in reacting Diesel sprays

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