Initial dynamic development of fuel spray analyzed by ultra high speed imaging

Ding, Haichun; Wang, Ziman; Li, Yanfei; Xu, Hongming; Cheng-ji, Zuo

doi:10.1016/j.fuel.2015.11.083

Cited by 32 publications

(18 citation statements)

References 18 publications

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“…Fig. 17 also confirms what has already been discussed: in average throughout the test matrix and for both nozzles, sprays produced by n-heptane feature larger dispersion (both angle and fluctuations) when compared to those of n-dodecane and the Surrogate fuel [66,67]. Also, the dispersion of the n-dodecane spray is less affected by the nozzle geometry in comparison to the Surrogate spray, and this result is in agreement with the spray tip penetration results presented in Figs.…”

Section: A Further Analysis On Nozzle and Fuel Effects On Spray Formasupporting

confidence: 86%

“…n-Heptane sprays feature the largest macroscopic spreading angles through the whole test matrix, in agreement with the spray penetration curves presented in Figs. 14 and 15, due to its lower density, viscosity and surface tension [66,67]. Also in agreement with the penetration results, the trends between n-dodecane and Surrogate sprays depend on the nozzle, or the cavitation regime.…”

Section: Spray Formation For Different Fuelssupporting

confidence: 82%

“…14 and 15 present results of select test conditions, to illustrate how nozzles k15 and k0, respectively, respond to the different fuels. In general, n-heptane shows slower penetration rates throughout the test matrix, which is expected due to the lower density, viscosity and surface tension, all which enhance liquid breakup and momentum exchange between fuel and ambient gas, as reported by Crua et al [66] and later Ding et al [67] in their microscopic studies. Fig.…”

Section: Spray Formation For Different Fuelsmentioning

confidence: 67%

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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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Section: A Further Analysis On Nozzle and Fuel Effects On Spray Formasupporting

confidence: 86%

Section: Spray Formation For Different Fuelssupporting

confidence: 82%

Section: Spray Formation For Different Fuelsmentioning

confidence: 67%

See 1 more Smart Citation

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

Payri

Viera

Gopalakrishnan

et al. 2016

Fuel

View full text Add to dashboard Cite

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“…The spray cone angle is determined by the upstream and downstream physical conditions and their interaction with each other. For the upstream, cavitation and liquid jet turbulence level are often observed, and the viscosity and ambient density have a great impact on the resulting cone angle . The cavitation at the nozzle entrance will shorten the jet breakup length but the long and undisrupted vapor cavity at the hole would increase the breakup length, which consequently leads to a non‐atomizing smooth jet .…”

Section: Influence Of Cavitation On Spray Atomization Characteristicsmentioning

confidence: 99%

Cavitation in Diesel Fuel Injector Nozzles and its Influence on Atomization and Spray

2018

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In combustors, high‐pressure fuel injector nozzles are employed for liquid atomization and spray generation. The internal flow within nozzles, especially cavitation, plays an important role in promoting the breakup of liquid jets. The formation mechanism and evolvement of cavitation are reviewed and described. Different cavitation regimes were characterized experimentally and the positive effect of cavitation on liquid atomization was confirmed. Different empirical formulas correlating the discharge coefficient with fluid‐dynamical parameters are summarized. The applicability, advantages, and disadvantages of two popular computational models for flow modeling, i.e., the interface tracking model and the homogeneous equilibrium model, are reviewed. The effects of cavitation on the generated spray are discussed.

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“…They concluded that the spray peak velocity is related to the change of two-stages of spray. Ding et al [15] investigated the near nozzle spray patterns with four different fuels through experimental method, and the results suggested that the hydraulic flipping regime is extremely different for four fuels under different injection pressures. Xie et al [16]experimented on the spray characteristics for different biodiesels and their blends with diesel under different injection conditions.…”

Section: Introductionmentioning

confidence: 99%

Experimental Investigation on the Early Stage Spray Characteristics with Biodiesel and Diesel

Yin

Wen

et al. 2017

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

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The early stage spray characteristics have a great impact on the secondary atomization progress, and thus affect the engine combustion and emission performances. The experimental investigation of the early stage spray behaviors with biodiesel and diesel was carried out by employing a laser-based Mie-scattering method. The results show that the spray tip penetration for biodiesel is higher than that for diesel at the early stage spray under the same injection pressure. Moreover, the early stage spray tip penetration can be longer under high injection pressures for two fuels. Besides, the early stage spray cone angle for biodiesel is narrower than that for diesel, and the spray cone angle is especially higher than biodiesel by 25.8% after start of injection time of 0.01ms. Furthermore, under the same injection condition, the difference of early stage spray area between diesel and biodiesel is not obvious, while the spray volume for biodiesel is larger than that for diesel, and also the spray volume can be enlarged by increasing injection pressure for both fuels. KeywordsSpray characteristics; Mie-scattering; Biodiesel; Diesel Introduction For modern diesel engines, soot and nitrogen oxide are the two main emissions which are mainly influenced by mixture quality of air and fuel, and the emission characteristics are largely governed by atomization and spray processes [1][2][3][4]. Biodiesel, derived from the waste cooking oil and a kind of renewable energy, has been widely used as an alternative fuel for diesel engines. It is clear that the use of biodiesel in diesel engine can improve favorable emissions performance [5][6][7][8][9]. Although the importance of biodiesel in reducing diesel engine emission performance has been acknowledged, the research on early stage spray characteristics of biodiesel is still far from sufficient. The early stage spray dominates the secondary spray progress and the mixture quality of fuel and air, and thus affects the atomization quality of biodiesel. Therefore, it is important to define the effects of biodiesel at the early stage spray characteristics. Wang et al. [10,11] studied the near-field primary spray characteristics of different split injection strategies by using ultra-high speed imaging method. Their results indicated that the second split injection cause smaller spray area and shorten penetration during the early stage spray, and also the larger late injection stage can increase the spray area and the penetration. Moreover, they found that the strong primary collision can be caused by improving the injection pressure and shortening dwell split injection, thus the spray area and the spray cone angle increase, while the spray tip penetration decreases at the same time. And they also found that the long duration of the first injection enhances the primary collision. Wang et al. [12] also studied the spray behaviors of emulsified diesel blended with water through schlieren technique. They concluded that the penetration increases as the magnitude of water increases, wh...

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Initial dynamic development of fuel spray analyzed by ultra high speed imaging

Cited by 32 publications

References 18 publications

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

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

Cavitation in Diesel Fuel Injector Nozzles and its Influence on Atomization and Spray

Experimental Investigation on the Early Stage Spray Characteristics with Biodiesel and Diesel

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