Microscopic Characterization of Diesel Sprays at VCO Nozzle Exit

982542

10/19/1998

Event
International Fall Fuels and Lubricants Meeting and Exposition
Authors Abstract
Content
A long-distance microscope with pulse-laser as optical shutter up to 25kHz was used to magnify the diesel spray at the nozzle hole vicinity onto 35-mm photographic film through a still or a high-speed drum camera. The injectors examined are high-pressure valve-covered-orifice (VCO) nozzles, from unit injector and common rail injection systems. For comparison, a mini-sac injector from a hydraulic unit injector is also investigated. A phase-Doppler particle analyzer (PDPA) system with an external digital clock was also used to measure the droplet size, velocity and time of arrival relative to the start of the injection event. The visualization results provide very interesting and dynamic information on spray structure, showing spray angle variations, primary breakup processes, and spray asymmetry not observed using conventional macroscopic visualization techniques. The near-field spray behavior is shown to strongly depend on the nozzle geometry, needle lift dynamics, and injection pressure, which is a function of the injection system.
Meta TagsDetails
DOI
https://doi.org/10.4271/982542
Pages
11
Citation
Lai, M., Wang, T., Xie, X., Han, J. et al., "Microscopic Characterization of Diesel Sprays at VCO Nozzle Exit," SAE Technical Paper 982542, 1998, https://doi.org/10.4271/982542.
Additional Details
Publisher
Published
Oct 19, 1998
Product Code
982542
Content Type
Technical Paper
Language
English