Diesel ignition delay and lift-off length through different methodologies using a multi-hole injector

Payri, Raúl; Salvador, F.J.; Manin, Julien; Viera, Alberto

doi:10.1016/j.apenergy.2015.10.118

Cited by 83 publications

(67 citation statements)

References 35 publications

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“…The core of the segmentation algorithm is based in a fixed threshold intensity-sensitive method [3,5,10,15]. But to improve the contour detection capabilities, an image-temporal-derivative approach [9,16,17] was added.…”

Section: Image Processing Methodologymentioning

confidence: 99%

“…The test chamber presents constant pressure and flow throughout its section, while a group of compressors, high-pressure reservoirs, and heaters provide the necessary conditions for testing purposes. The facility is explained in more detail in the work of other authors [3,5]. The fuel delivery system is made up of commercially available components.…”

Section: Testing Facilitymentioning

confidence: 99%

“…The diameter for both diaphragms was set to 4 mm, to have the same sensitivity at the cut-off plane. Previous authors [3,5,9] proved that this diaphragm size provides a proper balance for spray and background segmentation for the Schlieren setups in the facility. Both cameras were set to the same speed, resolution, exposure, and equipped with the same lens.…”

Section: Optical Setup For Vapor Phase Visualizationmentioning

confidence: 99%

“…Researchers have used Schlieren imaging to analyze the transient vapor phase of the diesel sprays in both nonreactive and reactive conditions. With this technique it is possible to measure simple macroscopic parameters, like spray tip penetration and spreading angle [2,3], to more complex variables, like ignition delay [4][5][6][7] or even lift-off length [8]. It is not only fundamental knowledge to understand how boundary conditions affect these variables, but the experimental data is necessary to validate computational tools, such as 1-D models or computational fluid dynamics (CFD).…”

Section: Introductionmentioning

confidence: 99%

“…It is not only fundamental knowledge to understand how boundary conditions affect these variables, but the experimental data is necessary to validate computational tools, such as 1-D models or computational fluid dynamics (CFD). The two most common Schlieren configurations are single-pass (SP) [2,[5][6][7][8][9] and double-pass (DP) [3,[10][11][12][13]. Typically, the first setup is used for axially drilled single-orifice nozzles, where vessels with multiple optical accesses allow line of sight visualization.…”

Section: Introductionmentioning

confidence: 99%

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Vapor phase penetration measurements with both single and double-pass Schlieren for the same injection event

Payri

Salvador

Viera

2017

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

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Schlieren imaging has been adopted as a standard optical technique for the analysis of diesel sprays under engine like conditions. A single-pass Schlieren arrangement is typically used for the study of single-orifice nozzles, as vessels with multiple optical accesses regularly allow line of sight visualization. Contrarily, for multi-spray nozzles, measurements are commonly performed through a single optical access, in which case a double-pass arrangement is employed. As a consequence, the light beams pass through the test section twice, increasing the optical sensitivity of the Schlieren setup. However, the impact this has on the macroscopic spray characteristics is still unclear. The scope of this study is to analyze the differences in vapor phase penetration for the same injection event, through high-speed imaging, for both single and double-pass Schlieren configurations. Experiments were carried out with a three hole nozzle with a nominal orifice diameter of 90 µm, named Spray B from the Engine Combustion Network, using commercially available diesel fuel and in non-reactive conditions. The impact of different injection pressures and chamber densities on the spray captured by each setup was assessed. On the results, vapor phase penetration followed the expected trend found in the literature, as it increases with increasing injection pressure and decreasing chamber density. Comparing the optical setups, vapor phase penetration obtained with the double-pass arrangement was marginally higher. The deviation was observed throughout all tested conditions. Although the discrepancy was approximately constant for different injection pressures and chamber temperature, it increased with increasing density. These results highlight the importance of a proper understanding regarding the limitations of optical diagnostics, in particular for results used in calibration of computational models.

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