Measurement of Diesel Spray Formation and Combustion upon Different Nozzle Geometry using Hybrid Imaging Technique

Zhang, Anqi; Montanaro, Alessandro; Allocca, Luigi; Naber, Jeffrey; Lee, Seong-Young

doi:10.4271/2014-01-1410

Cited by 30 publications

(18 citation statements)

References 17 publications

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“…In both studies, authors perform numerical simulations of isothermal and evaporative sprays for cylindrical and conical nozzles, showing that the penetration curves start to diverge after a certain time has passed and aerodynamic interaction has played its part, even though the effect of nozzle geometry is just introduced as boundary conditions at the orifice interface. Note that Montanaro et al [17] observed the same trend in their experimental results, presented in the same paper but discussed in detailed further by Zhang et al [18].…”

Section: Comparing Nozzlessupporting

confidence: 69%

“…Contrasting these studies, several authors show that the flow inside the nozzle influences the near-nozzle region of the spray in terms of liquid-phase break-up, liquid length, and spray angle [5][6][7][8][9][10][11]. Many other studies also evidence the effects of nozzle flow characteristics over the macroscopic spray [6,[12][13][14][15][16][17][18]. This contrast, along with the remaining uncertainty on the effect of nozzle geometry on entrainment, combustion, and pollutant formation, leaves room for fundamental questions on the subject.…”

Section: Introductionmentioning

confidence: 96%

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The effect of nozzle geometry over the evaporative spray formation for three different fuels

Payri

Viera

Gopalakrishnan

et al. 2017

Fuel

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Section: Comparing Nozzlessupporting

confidence: 69%

Section: Introductionmentioning

confidence: 96%

The effect of nozzle geometry over the evaporative spray formation for three different fuels

Payri

Viera

Gopalakrishnan

et al. 2017

Fuel

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“…In both studies, authors perform numerical simulations of the liquid spray for cylindrical and conical nozzles, showing that the penetration curves start to diverge after a certain time has passed and aerodynamic interaction has played its part, even though the effect of nozzle geometry is just introduced as boundary conditions at the orifice interface. Note that Montanaro et al [6] observed the same trend in their experimental results, presented in the same paper but detailed further by Zhang et al [20]. Finally, it is important to point out that the difference between the behavior of the two nozzles is not independent of fuel, and is smaller for n-dodecane in comparison to the Surrogate fuel case shown in Fig.…”

Section: Distance [Mm]supporting

confidence: 55%

“…Contrasting these studies, several authors show that the flow inside the nozzle influences the nearnozzle region of the spray in terms of liquid-phase break-up, liquid length, and spray angle [9][10][11][12][13][14][15][16]. Many other studies also evidence the effects of nozzle flow characteristics over the macroscopic spray [3,4,6,11,[17][18][19][20]. This contrast, along with the remaining uncertainty on the effect of nozzle geometry on entrainment, combustion, and pollutant formation, leave room for fundamental questions on the subject.…”

Section: Introductionmentioning

confidence: 77%

The effect of nozzle geometry over internal flow and spray formation for three different fuels

Payri

Viera

Gopalakrishnan

et al. 2016

Fuel

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h i g h l i g h t sTwo single hole nozzle (cylindrical and convergent) are used. A complete hydraulic characterization is done along with spray visualization. A fast pulsed light source is synchronized to a fast camera working at 160 kHz. The effect of nozzle geometry is analyzed for three different fuels. A large set of experimental data was obtained, which could be used for model validation. a b s t r a c tThe influence of internal nozzle flow characteristics over macroscopic spray development is studied experimentally for two different nozzle geometries and three fuels. The measurements include a complete hydraulic characterization consisting of instantaneous injection rate and spray momentum flux measurements, followed by a high-speed visualization of isothermal liquid spray in combination with cylindrical and conical nozzle configurations. Two of the fuels are pure components-n-heptane and ndodecane-while the third fuel consists of a three-component surrogate to better represent the physical and chemical properties of diesel fuel. The cylindrical nozzle with 8.6% larger diameter, in spite of higher mass flow rate and momentum flux, shows slower spray tip penetration when compared to the conical nozzle. The spreading angle is found to be inversely proportional to the spray tip penetration. The spreading angle is largely influenced by the nozzle geometry and the ambient density. Rail pressure was found to have weak influence on the near-field spreading angle and no influence on the standard deviation of the spreading angle. n-Heptane spray shows slowest penetration rates while n-dodecane and the surrogate fuel mixture show very similar spray behavior for variations in injection pressure and back pressure. However, the surrogate fuel mixture shows higher penetration than n-dodecane when using the conical nozzle and lower penetration than n-dodecane when using cylindrical nozzle.

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“…The physics of the effects of nozzle geometry on in-cylinder spray development and combustion is still of interest to the research community and the auto-industry. For example, the survey in this work [7,28], supported by other investigations [23,24], clearly showed the significant effects of nozzle flow characteristics on spray development. This contrasts with other works [25,26] which suggested negligible influence of nozzle flow characteristics over spray formation.…”

mentioning

confidence: 51%

Fuel spray vapour distribution correlations for a high pressure diesel fuel spray cases for different injector nozzle geometries.

Njere

Emekwuru

2017

Proceedings ILASS–Europe 2017. 28th Conference on Liquid Atomization and Spray Systems

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The evolution of diesel fuel injection technology, to facilitate strong correlations of in-cylinder spray propagation with injection conditions and injector geometry, is crucial in facing emission challenges. More observations of spray propagation are, therefore, required to provide valuable information on how to ensure that all the injected fuel has maximum contact with the available air, to promote complete combustion and reduce emissions. In this study, high pressure diesel fuel sprays are injected into a constant-volume chamber at injection and ambient pressure values typical of current diesel engines. For these types of sprays the maximum fuel liquid phase penetration is different and reached sooner than the maximum fuel vapour phase penetration. Thus, the vapour fuel could reach the combustion chamber wall and could be convected and deflected by swirling air. In hot combustion chambers this impingement can be acceptable but this might be less so in larger combustion chambers with cold walls. The fuel-ambient mixture in vapourized fuel spray jets is essential to the efficient performance of these engines. For this work, the fuel vapour penetration values are presented for fuel injectors of different k-factors. The results indicate that the geometry of fuel injectors based on the k-factors appear to affect the vapour phase penetration more than the liquid phase penetration. This is a consequence of the effects of the injector types on the exit velocity of the fuel droplets. KeywordVapour, spray, k-factor, shadowgraph. IntroductionSpray formation occurs with the introduction of liquid into a gaseous environment through an orifice such that the liquid breaks-up into droplets by interacting with the surrounding gases and causing its own unsteadiness [3]. For diesel engines, spray characteristics (liquid/vapour penetration and distribution) significantly affect the combustion and emission processes. By optimizing these characteristics, the tailpipe emissions, mainly oxides of Nitrogen (NOx) and partciculate matter (PM), can be minimized [2]. Spray penetration, which is usually analysed macroscopically, considers the development of the liquid and vapour components. It is desirable to achieve optimal travel of these spray components to avoid the adverse effects of impingement caused by under/overpenetration of liquid spray [19,20]. Advances in fuel injection system, with the introduction of the common rail technology, have provided increased controllability of the injection event. The analyses of injection system development have been presented from several viewpoints. Nozzle geometry has been studied for the influence on the internal flow and spray characteristics with respect to: atomization [4,5], mixing processes [6,7], emission [9,10] and cavitation [8,13]. Different injection strategies have been investigated to show the effect on pollutant emissions [2,3]. Specific studies have also been conducted with conical and cylindrical nozzles [11,12], and to develop more understanding on the effects of nozzl...

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Measurement of Diesel Spray Formation and Combustion upon Different Nozzle Geometry using Hybrid Imaging Technique

Cited by 30 publications

References 17 publications

The effect of nozzle geometry over the evaporative spray formation for three different fuels

The effect of nozzle geometry over the evaporative spray formation for three different fuels

The effect of nozzle geometry over internal flow and spray formation for three different fuels

Fuel spray vapour distribution correlations for a high pressure diesel fuel spray cases for different injector nozzle geometries.

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