Investigation on the Characteristics of Diesel Fuel Spray

Kuniyoshi, Hikaru; Tanabe, Hideaki; Sato, G. Takeshi; Fujimoto, Hajime

doi:10.4271/800968

Cited by 53 publications

(10 citation statements)

References 9 publications

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“…This observation of large ensembles or structures of fuel are in accordance with the report of Zurlo and Chigier [22], who measured the linear depolarization ratio. They concluded that non-spherical scatterers are mixed with spherical droplets in an outer mixing flow region that has already been described by Kuniyoshi et al [21]. In Figure 16 the velocity distribution of the jet shown in Figure 15 is depicted.…”

Section: Single Droplet Results 1 Ms After Injection Begansupporting

confidence: 57%

“…This observation is in accordance with Kuniyoshi's description of Diesel sprays. He called this part of the jet the "initial region" and claimed that its length is almost independent of the surrounding pressure and equal to lOmm [21]. In Figure 13 the jet is observed at ljet = 5, 7 and 9mm, corresponding to T = 70,75 and 80ps in the first three frames.…”

Section: Processes Leading To Jet Formationmentioning

confidence: 95%

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Holographic Investigations of a Diesel Jet injected into a high‐pressure test chamber

Schaller

Stojanoff

1996

Part & Part Syst Charact

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A Diesel spray injected into a high‐pressure test chamber was investigated with two different holographic techniques. The usual off‐axis recording geometry was used to investigate the very early beginning of the injection. Double pulsing of the recording laser facilitated velocity measurements. By using two different reference angles for the two recording the two images can be separated upon reconstruction of the holograms. Thus superior image quality could be achieved. Processes leading to jet formation could be identified: the spray tip is periodically axially decelerated and radially accelerated. Consequently, liquid moves at the tip off axis. The spray consists of fast central region surrounded by a slower outer jet region. The outer jet region exhibits periodic droplet concentration fluctuations which are interpreted as a result of the periodic processes at the spray tip. Some high concentration regions in the outer jet region were investigated using a dark‐field holographic technique. This technique permits single droplet velocity measurements and local droplet concentration determination at extremely high droplet concentrations. The most important result of these investigations is that no correlation between the local droplet concentration and the droplet velocity could be found.

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Section: Single Droplet Results 1 Ms After Injection Begansupporting

confidence: 57%

Section: Processes Leading To Jet Formationmentioning

confidence: 95%

Holographic Investigations of a Diesel Jet injected into a high‐pressure test chamber

Schaller

Stojanoff

1996

Part & Part Syst Charact

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“…8(c) the liquid mass distributions are very similar among all test nozzles and the relatively higher mass region of the liquid phase inside the spray exists mainly in the central part, closer to the tip of the spray. For a single-hole nozzle spray, droplets in the spray tip region lose their momentum gradually with time, owing to the ambient gas resistance, and are caught up by the droplets injected later, then collide and coalesce with each other [40]. For a group-hole nozzle spray, droplet collision and coalescence occurs additionally in the overlapping part of the two separate jets.…”

Section: Evaporating Free Spraysmentioning

confidence: 99%

An investigation of mixture formation and in-cylinder combustion processes in direct injection diesel engines using group-hole nozzles

Gao

Matsumoto

Namba

et al. 2009

International Journal of Engine Research

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Mixture properties of the transient fuel spray injected by group-hole nozzles were quantitatively studied in a constant volume chamber via the laser absorption scattering (LAS) technique, and compared with conventional single-hole nozzles. Specific areas investigated included non-evaporating and evaporating ambient conditions, and the conditions of free spray and spray impinging on a flat wall. The particular emphasis was on the effect of one of the key parameters of the group-hole nozzle structure, namely, the interval between orifices. Subsequently, in-cylinder ignition and combustion processes were investigated by direct flame visualization in a single-cylinder optical research engine using the group-hole nozzle and the standard multi-hole nozzle, together with heat release analysis. Results show that the grouphole nozzle can produce a smaller Sauter mean diameter (SMD) of droplets under the nonevaporating condition. Under the evaporating condition, for the free spray cases, there exists a trade-off between the fuel evaporation and the spray penetration in the application of the group-hole nozzle. With the increase in interval between orifices, the ratio of evaporation increases, but the spray tip penetration decreases. For the spray impinging on a flat wall, the group-hole nozzle can enhance the spray tip penetrations to some extent compared with the single-hole nozzles. Flame images taken in a direct injection optical engine show that the enhancement of the fuel atomization and evaporation by the group-hole nozzle may contribute to a decrease in overall flame luminosity level, suggesting reduced soot formation in diesel engines.

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“…In early times, Ricou and Spalding 10 and Hill 11 studied the air entrainment law of a steady gas jet by using the 'porous-wall technique' and concluded that the air entrainment rate increases linearly with axial distance after reaching the fully developed region. Kuniyoshi et al 12 investigated the ambient gas flow field around a diesel spray by using a smoke wire method. Cho et al 13 also investigated the surrounding gas flow field of the diesel spray with an injection pressure of 40 MPa by means of the smoke wire method.…”

Section: Introductionmentioning

confidence: 99%

An investigation of the effects of fuel injection pressure, ambient gas density and nozzle hole diameter on surrounding gas flow of a single diesel spray by the laser-induced fluorescence–particle image velocimetry technique

Zhu

Kuti

Nishida

2012

International Journal of Engine Research

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The characteristics of ambient gas motion induced by a single diesel spray were measured quantitatively by using a laserinduced fluorescence-particle image velocimetry technique under non-evaporating quiescent conditions. The effects of fuel injection pressure, ambient gas density and nozzle hole diameter on the ambient gas mass flow rate into the spray through the whole spray periphery (spray side periphery and tip periphery) were investigated quantitatively according to the gas flow velocity measurements. The results show that the captured gas mass flow rate through the spray tip periphery is prominent in the whole periphery and the proportion of the gas entrainment through the spray side periphery increases with spray development. The higher injection pressure significantly enhances the total gas mass flow rate through the whole periphery; however, the increase in the ratio of ambient gas and fuel mass flow rate becomes moderate gradually with the increase in the injection pressure. The higher ambient gas density results in a slight increase in ambient gas flow velocity along the spray side periphery and the tip periphery and a reduction of the spray volume; however, the ambient gas mass flow rate was apparently enhanced. The smaller nozzle hole diameter results in a significant decrease in the ambient gas mass flow rate and an increase in the ratio of the gas and fuel mass flow rate. Numerical simulation results provide more understanding of the spray-induced gas flow field and validate the measurement accuracy of the laser-induced fluorescence-particle image velocimetry results.

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Investigation on the Characteristics of Diesel Fuel Spray

Cited by 53 publications

References 9 publications

Holographic Investigations of a Diesel Jet injected into a high‐pressure test chamber

Holographic Investigations of a Diesel Jet injected into a high‐pressure test chamber

An investigation of mixture formation and in-cylinder combustion processes in direct injection diesel engines using group-hole nozzles

An investigation of the effects of fuel injection pressure, ambient gas density and nozzle hole diameter on surrounding gas flow of a single diesel spray by the laser-induced fluorescence–particle image velocimetry technique

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