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Download fileDroplet size development in a DISI injector fuel spray
conference contribution
posted on 2017-02-17, 13:32 authored by Changzhao Jiang, Matthew C. Parker, Adrian SpencerAdrian Spencer, Graham Wigley, Colin GarnerColin Garner, J. HelieIn this work, Phase Doppler Anemometry (PDA) measurements are used to test the hypothesis that the mean droplet size in Direct Injection Spark Ignition (DISI) engine fuel spray increases with distance from the injector due to the evaporation of the smaller droplets. In order to understand the role of evaporation, two velocity components and drop size PDA measurements were performed for one plume of a DISI injector using two fuels with widely differing vapour pressures. The measurements were taken along the plume centreline at four different vertical
distances from the injector tip between 20 to 50 mm. on the plume centreline to evaluate the development of droplet size distributions along the plume. Measurements are also made across the plume (perpendicular to the plume
centreline) at the 30 and 50 mm locations. Measurements using PDA closer to the injector are more difficult due to
the high spray density (particularly apparent at 20mm or closer to the injector). A data fitting process is suggested using joint probability distribution functions (JPDFs) to reduce the effect of statistical significance where data rates are low. This improves the description of the PDA derived drop size distribution in regions where the data validation rate is poor. It is found that the evaporation is not the main cause for droplet size increase along the
plume. The most likely reason for the increase of the Sauter Mean Diameter (SMD) with distance from the injector is that the smaller droplets move away from the plume centreline through turbulent diffusion at a higher rate compared to larger droplets. Higher axial momentum of the larger droplets reduces their response to turbulent velocity fluctuations and hence their path-lines are less prone to stray from their initial trajectory.
Funding
The authors would like to acknowledge the financial support of the Advanced Propulsion Centre (APC) for this work which was undertaken as part of TSB/APC project number 101891.
History
School
- Mechanical, Electrical and Manufacturing Engineering
Published in
18th International Symposium on Applications of Laser Techniques to Fluid MechanicsCitation
JIANG, C. ... et al, 2016. Droplet size development in a DISI injector fuel spray. IN: Proceedings of the 18th International Symposium on Application of Laser and Imaging Techniques to Fluid Mechanics, Lisbon, Portugal, 4th-7th July 2016, pp. 2834-2847.Publisher
© LISBON SimposiaVersion
- AM (Accepted Manuscript)
Publisher statement
This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/Acceptance date
2016-03-17Publication date
2016Notes
This is a conference paper.Publisher version
Language
- en