Quantitative Measurement of Liquid and Vapor Phase Concentration Distributions in a D.I. Gasoline Spray by the Laser Absorption Scattering (LAS) Technique

Yamakawa, Masahisa; Takaki, Daisuke; Li, Tie; Zhang, Yu-yin; Nishida, Keiya

doi:10.4271/2002-01-1644

Cited by 21 publications

(15 citation statements)

References 7 publications

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“…Besides Schlieren imaging, the vapor penetration of non-reacting spray was also measured by a developed UV-LA technique which is based on the ultraviolet (UV) light attenuation by the vapor phase [14,25]. Because of this absorption for UV light, the intensity within the spray is much lower than that of the background gas area.…”

Section: Uv-ligth Absorption (Uv-la)mentioning

confidence: 99%

An Experimental Study on Diesel Spray Injection into a Non-Quiescent Chamber

Pastor¹,

García-Oliver²,

García³

et al. 2017

SAE Int. J. Fuels Lubr.

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Visualization of single-hole nozzles into quiescent ambient has been used extensively in the literature to characterize spray mixing and combustion. However in-cylinder flow may have some meaningful impact on the spray evolution. In the present work, visualization of direct diesel injection spray under both non-reacting and reacting operating conditions was conducted in an optically accessible two-stroke engine equipped with a singlehole injector. Two different high-speed imaging techniques, Schlieren and UV-Light Absorption, were applied here to quantify vapor penetration for non-reacting spray. Meanwhile, Mie-scattering was used to measure the liquid length. As for reacting conditions, Schlieren and OH* chemiluminescence were simultaneously applied to obtain the spray tip penetration and flame lift-off length under the same TDC density and temperature. Additionally, PIV was used to characterize in-cylinder flow motion. Results were compared with those from the Engine Combustion Network database obtained under quiescent ambient conditions in a high pressure high temperature vessel. Because of the air flow induced by piston movement, in-cylinder conditions in the two-stroke engine during the spray injection are highly unsteady, which has a significant impact on the spray development and interference on the spray visualization. From the comparison with quiescent data from the Engine Combustion Network, air flow induced by piston movement was found to slow down tip penetration. Moreover, both ignition delay and lift-off length under unsteady flow conditions show less sensitivity with ambient temperature than that of quasi-steady conditions.

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Section: Uv-ligth Absorption (Uv-la)mentioning

confidence: 99%

An Experimental Study on Diesel Spray Injection into a Non-Quiescent Chamber

Pastor¹,

García-Oliver²,

García³

et al. 2017

SAE Int. J. Fuels Lubr.

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“…20 A wide range of non-intrusive diagnostics have also been employed to study the spray and entrainment field. These include schlieren and shadowgraphy, Mie and Rayleigh scattering [17,[20][21][22], diffuse backlit illumination (DBI) [23][24][25], particle image velocimetry [12,26,27], laser absorption scattering [28], Raman spectroscopy [29] and laser induced fluorescence (LIF) [30][31][32][33] among others. Phase doppler interferometry (PDI) is also commonly used to measure droplet size and velocity where the flow is sufficiently dilute [21, 22, 25 …”

Section: Introductionmentioning

confidence: 99%

Internal and near nozzle measurements of Engine Combustion Network “Spray G” gasoline direct injectors

Duke

Kastengren

Matusik

et al. 2017

Experimental Thermal and Fluid Science

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Gasoline direct injection (GDI) sprays are complex multiphase flows. When compared to multi-hole diesel sprays, the plumes are closely spaced, and the sprays are more likely to interact. The effects of multi-jet interaction on entrainment and spray targeting can be influenced by small variations in the mass fluxes from the holes, which in turn depend on transients in the needle movement and small-scale details of the internal geometry. In this paper, we present a comprehensive overview of a multi-institutional effort to experimentally characterize the internal geometry and near-nozzle flow of the Engine Combustion Network (ECN) Spray G gasoline injector. In order to develop a complete picture of the near-nozzle flow, a standardized setup was shared between facilities. A wide range of techniques were employed, including both x-ray and visible-light diagnostics. The novel aspects of this work include both new experimental measurements, and a comparison of the results across different techniques and facilities. The breadth and depth of the data reveal phenomena which were not apparent from analysis of the individual data sets. We show that plume-to-plume variations in the mass fluxes from the holes can cause large-scale asymmetries in the entrainment field and spray structure.Both internal flow transients and small-scale geometric features can have an effect on the external flow. The sharp turning angle of the flow into the holes also causes an inward vectoring of the plumes relative to the hole drill angle, which increases with time due to entrainment of gas into a low-pressure region between the plumes. These factors increase the likelihood of spray collapse with longer injection durations.

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“…The necessary condition is that the extinction of ultraviolet light is due to the absorption of vapor phase spray and both the scattering and absorption of liquid droplets whereas the extinction of visible light is due to only the scattering of liquid droplets. In a dispersed cloud droplets like DISI gasoline spray (mean diameter larger than 7 µm), the extinction efficiency tends to be the same regardless of the wavelength of incident light (7) . Thus, from the extinction difference, the vapor concentration distribution can be obtained according to the Lambert-Beer's law.…”

Section: Laser Absorption Scattering (Las) Techniquementioning

confidence: 99%

“…The injection pressure was 5 MPa. The ambient pressure and temperature were 1.0 MPa and 500 K. For the detailed information of the LAS technique and the pressure-swirl injector, readers can refer to the published paper of the authors (7) .…”

Section: Laser Absorption Scattering (Las) Techniquementioning

confidence: 99%

Enhancement of Stratified Charge for DISI Engines through Split Injection(Effect and Its Mechanism)

Nishida

Zhang

et al. 2005

JSME Int. J., Ser. B

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The effect of split injection on the mixture characteristics of DISI (Direct Injection Spark Ignition) engines was investigated firstly by the Laser Absorption Scattering (LAS) technique. Through splitting the fuel injection process, two possible benefits were found: 1) High density liquid droplets piling up at the leading edge of the spray can be circumvented, subsequently the reduction of the spray tip penetration; 2) The quantity of "over lean" (φ v < 0.7, φ v : equivalence ratio of vapor) mixture in the spray can be significantly reduced. These are believed to contribute to the reduction of the engine-out smoke and HC emissions. In order to clarify the mechanism behind the effect of the split injection, the spray-induced ambient air motion was investigated by the LIF-PIV technique. The strong ambient air entrainment into the tail region of the spray and a counter-vortex structure were found in both the single and split injections. In the case of the single injection, the spray develops in extending its length, subsequently a larger volume results and thus it is diluted to "over lean" by the ambient air entrainment. In contrast, in the case of split injection, the second spray is injected into the tail region of the first spray and its evaporation is promoted by the ambient air motion induced by the first spray. Hence the replenishment of the liquid fuel into the leading edge of the first spray is reduced. As a consequence, the high density liquid droplets piling up at the leading edge is avoided. Furthermore, a more compact spray results so that the ambient air motion plays a positive role on evaporating the spray into "more combustible" (0.7 < φ v < 1.3). This is especially true in the tail region of the spray and the region where the counter-vortex motion is occurring.

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Quantitative Measurement of Liquid and Vapor Phase Concentration Distributions in a D.I. Gasoline Spray by the Laser Absorption Scattering (LAS) Technique

Cited by 21 publications

References 7 publications

An Experimental Study on Diesel Spray Injection into a Non-Quiescent Chamber

An Experimental Study on Diesel Spray Injection into a Non-Quiescent Chamber

Internal and near nozzle measurements of Engine Combustion Network “Spray G” gasoline direct injectors

Enhancement of Stratified Charge for DISI Engines through Split Injection(Effect and Its Mechanism)

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