Investigations on Gasoline Spray Propagation Behaviour Characteristic for Multihole Injectors

Krämer, Martin; Kull, Eberhard; Heldmann, Markus; Wensing, Michael

doi:10.4271/2014-01-2732

Cited by 11 publications

(8 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…11 that is not apparent in the planar radiography (Fig. 8a-b) is that the left-side plumes (1-5) have higher peak densities than the right-side plumes (6)(7)(8). As the density field 245 is computed tomographically from projections of the spray made from multiple angles, there is no spatial bias in the reconstruction that might generate such an asymmetry artifically.…”

mentioning

confidence: 99%

See 1 more Smart Citation

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

View full text Add to dashboard Cite

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.

show abstract

mentioning

confidence: 99%

“…GDI spray measurements are challenging for a variety of reasons. The plumes are closely spaced and have a tendency to merge or collapse [6][7][8][9]. It is difficult to optically access individual plumes.…”

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

View full text Add to dashboard Cite

show abstract

“…The spray visualization is done by false color-displayed average grayscale images. Additional information about the measurement setup and the image post processing algorithm can be viewed in Kra¨mer et al 49 The systematic variation in backpressure (0.03-0.10 MPa) and fuel temperature (303-368 K) at 20 MPa injection pressure covers engine-relevant operation conditions in a wide range. At 111 operation points, the parametric study displays identical boundary conditions as well as fluid-specific superheating levels for the reference gasoline RF-02-08 and the selected single-component alkanes.…”

Section: Jet-to-jet Interactionsmentioning

confidence: 99%

Flashboiling-induced targeting changes in gasoline direct injection sprays

Krämer

Kull

Wensing

2015

International Journal of Engine Research

Self Cite

View full text Add to dashboard Cite

By definition, flashboiling is referred to as superheated injections. The sudden occurrence of boiling inside the fuel can change the spray structure dramatically. Up to 99% of all injection processes during the New European Driving Cycle and 95% during 'Real Driving Emissions' tests are, with respect to mid-range cars, in a state of thermodynamic nonequilibrium below the specific vapor pressure of gasoline. Considering this fact, the scientific question is not the appearance of flashboiling during the operation of stoichiometric homogeneous charge direct injection gasoline engines but the intensity of occurring spray processes and their influence on nominal spray designs. As a consequence of induced targeting changes, the positive influence of flashboiling on the droplet size distribution and the penetration depth can be counteracted. As main driving factors for targeting changes, jet-to-jet interactions can be identified. By applying appropriate nozzle design features, the potential of flashboiling can be exploited and the targeting changes of the nominal spray designs, considered negatively, are avoided mostly. This work focuses on flashboiling-induced targeting changes, the socalled phenomenon of ''spray collapse'': its root cause, development and avoidance.

show abstract

“…Real gasolines are blends of hundreds of hydrocarbons, with a boiling point range of typically 303-473K, dependent on the exact composition. Kraemer et al [8] computed the occurrence of flash boiling during normalised car testing cycles, based upon representative fuel injection timing, engine cylinder pressure and fuel temperature for a for a mid-range 1360 kg car fitted with a 4 cylinder, 1.4l, 91kW engine. They found that the engine performance was partly influenced by superheating during most of the regulated drive cycles.…”

Section: Introductionmentioning

confidence: 99%

Impact of gasoline direct injection fuel injector hole geometry on spray characteristics under flash boiling and ambient conditions

Jiang

Parker

Hélie

et al. 2019

Fuel

View full text Add to dashboard Cite

The effect of injector nozzle design on the Gasoline Direct Injection (GDI) fuel spray characteristics under atmospheric and flash boiling conditions was investigated using Phase Doppler Anemometry (PDA) measurements. To understand the impact of hole diameter and conicity, experiments were conducted on two bespoke 3-hole injectors in a pressure and temperature controlled constant volume chamber and in the open air. The measurements were taken radially outward from the injector axis to the outer extent of the plume at distances of 15 mm, 25 mm and 40 mm from the injector tip. Observations of the influence of surrounding gas and temperature conditions and hole design on the injector spray performance were made. Under non-flash boiling conditions, it was found that the injection pressure dictates the length of the spray penetration before collapse occurs, with an increase in pressure resulting in an increase in this length. Comparison of mean velocity and droplet diameter data are also made to understand the performance under flash boiling conditions. Results show that, under flash boiling conditions, the droplet velocity significantly increases while the droplet size reduces. More importantly, it is found that the impact of the flash boiling environment on sprays of different hole geometries is different. Some hole designs offer more resistance against spray collapse. It was found that the mid-sized of the three hole diameters tested here was found to produce a spray that more readily collapsed than that of the smaller or larger hole diameters. In addition, it was found that under flash boiling conditions, the convergent hole had a greater propensity to exhibit spray collapse.

show abstract

Investigations on Gasoline Spray Propagation Behaviour Characteristic for Multihole Injectors

Cited by 11 publications

References 14 publications

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

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

Flashboiling-induced targeting changes in gasoline direct injection sprays

Impact of gasoline direct injection fuel injector hole geometry on spray characteristics under flash boiling and ambient conditions

Contact Info

Product

Resources

About