Diesel injector elasticity effects on internal nozzle flow

Yasutomi, Koji; Hwang, Joonsik; Manin, Julien; Pickett, Lyle M.; Arienti, Marco; Daly, Shane; Skeen, Scott A.

doi:10.4271/2019-01-2279

Cited by 14 publications

(6 citation statements)

References 19 publications

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“…For lifts under 2.5 µm the needle motion is stopped and an interior interface pre-defined at the sealing surface (surface of minimum distance between needle and housing) is changed to a wall separating the upstream part from the downstream region. The force that the needle valve exerts on the housing leads to elastic deformation and therefore the contact area between the two surfaces is a band of finite width [87]. However, in the current model this deformation is not modelled and the contact line between both surfaces is a single circle.…”

Section: Cavitation Modelmentioning

confidence: 96%

Modelling and prediction of cavitation erosion in GDi injectors operated with E100 fuel

Santos

Shi

Venkatasubramanian

et al. 2021

Fuel

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Section: Cavitation Modelmentioning

confidence: 96%

Modelling and prediction of cavitation erosion in GDi injectors operated with E100 fuel

Santos

Shi

Venkatasubramanian

et al. 2021

Fuel

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“…Like most high-pressure diesel hardware, it consisted of a solenoid driven, hydraulically lifted main needle. However, the hole was placed along the central axis of the nozzle tip, as in the Engine Combustion Network (ECN) "Spray-D" configuration (Engine Combustion Network (ECN), 2022c; Yasutomi et al, 2019). The exit diameter, internal taper (K-factor), and peak flow capacity of the single-hole nozzle were targeted to match those of one hole from the production part as closely as possible (Torelli et al, 2018).…”

Section: Injectormentioning

confidence: 99%

“…However, measurements at a charge gas temperature of 900 K, density of 23 kg/m 3 , and injection pressure of 1,500 bar were conducted across all operating conditions, fuels, and optical methods. This was done to provide consistency with ECN Spray-D data which shares a similar hardware configuration and has also been extensively studied (Engine Combustion Network (ECN), 2022c; Yasutomi et al, 2019). The high charge gas densities and temperatures correspond to in-cylinder environments for boosted, high compression ratio diesel engines.…”

Section: Test Conditionsmentioning

confidence: 99%

Non-Reacting Spray Characteristics of Gasoline and Diesel With a Heavy-Duty Single-Hole Injector

et al. 2022

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Gasoline compression ignition (GCI) is a promising combustion technology that could help alleviate the projected demand for diesel in commercial transport while providing a pathway to achieve upcoming CO2 and criteria pollutant regulations for heavy-duty engines. However, relatively high (i.e., diesel-like) injection pressures are needed to enable GCI across the entire load range while maintaining soot emissions benefits and managing heat release rates. There have only been a limited number of previous studies investigating the spray characteristics of light distillates with high-pressure direct-injection hardware under charge gas conditions relevant to heavy-duty applications. The current work aims to address this issue while providing experimental data needed for calibrating spray models used in simulation-led design activities. The non-reacting spray characteristics of two gasoline-like fuels relevant to GCI were studied and compared to ultra-low-sulfur diesel (ULSD). These fuels shared similar physical properties and were thus differentiated based on their research octane number (RON). Although RON60 and RON92 had different reactivities, it was hypothesized that they would exhibit similar non-reacting spray characteristics due to their physical similarities. Experiments were conducted in an optically accessible, constant volume combustion chamber using a single-hole injector representing high-pressure, common-rail fuel systems. Shadowgraph and Mie-scattering techniques were employed to measure the spray dispersion angles and penetration lengths under both non-vaporizing and vaporizing conditions. Gasoline-like fuels exhibited similar or larger non-vaporizing dispersion angle compared to ULSD. All fuels followed a typical correlation based on air-to-fuel density ratio indicating that liquid density is the main governing fuel parameter. Injection pressure had a negligible effect on the dispersion angle. Gasoline-like fuels had slower non-vaporizing penetration rates compared to ULSD, primarily due to their larger dispersion angles. As evidenced by the collapse of data onto a non-dimensional penetration correlation over a wide range of test conditions, all fuels conformed to the expected physical theory governing non-vaporizing sprays. There was no significant trend in the vaporizing dispersion angle with respect to fuel type which remained relatively constant across the entire charge gas temperature range of 800–1200 K. There was also no discernable difference in vapor penetration among the fuels or across charge temperature. The liquid length of gasoline-like fuels was much shorter than ULSD and exhibited no dependence on charge temperature at a given charge gas pressure. This behavior was attributed to gasoline being limited by interphase transport as opposed to mixing or air entrainment rates during its evaporation process. RON92 had a larger non-vaporizing dispersion angle but similar penetration compared to RON60. Although this seems to violate the original similarity hypothesis for these fuels, the analysis was made difficult due to the use of different injector builds for the experiments. However, RON92 did show a slightly larger vapor dispersion angle than RON60 and ULSD. This observation was attributed to nuanced volatility differences between the gasoline-like fuels and indicates that vapor dispersion angle likely relies on a more complex correlation beyond that of only air-to-fuel density ratio. Finally, RON92 showed the same quantitative liquid length and insensitivity to charge gas temperature as RON60.

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“…The reason for this order of magnitude difference still has not been reported. As injection pressures increase, the needle valve assembly experiences elastic deformation, [44][45][46] expanding the clearance of the needle guidance, 47,48 and deforming the moving components (control plunger, needle, and rod) in the axial direction. [49][50][51][52][53] Nevertheless, to the best of authors' knowledge, there is no research conducted on the bending deformation of the needle in the radial direction and the relevance of the clearance gap changing in the upstream with the eccentricity of the needle tip.…”

Section: Introductionmentioning

confidence: 99%

An analytical model of diesel injector’s needle valve eccentric motion

Wang

Moro

Jin

et al. 2021

International Journal of Engine Research

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Past experimental studies have shown that the needle valve of high-pressure diesel injectors undergoes lateral movement and deformation, while the continuous increase in injection pressure enlarges the gap of the needle valve assembly. Two different analytical models, considering or omitting this change are presented here, linking the geometries of the needle valve assembly with the magnitude of needle valve tip lateral movement. It is found that the physical dimensions of the needle valve assembly and the injection pressure have a significant impact on the radial displacement of the needle. For example, for nominal clearances between the needle guidance and the needle valve of about 1–3 μm, the magnitude of the radial movement of the needle tip could reach tens of microns. The model that takes into account the variation of the gap between the needle guide and needle valve is found to give predictions closer to the experimental results.

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Diesel injector elasticity effects on internal nozzle flow

Cited by 14 publications

References 19 publications

Modelling and prediction of cavitation erosion in GDi injectors operated with E100 fuel

Modelling and prediction of cavitation erosion in GDi injectors operated with E100 fuel

Non-Reacting Spray Characteristics of Gasoline and Diesel With a Heavy-Duty Single-Hole Injector

An analytical model of diesel injector’s needle valve eccentric motion

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