Eccentric needle motion effect on near-nozzle dynamics of diesel spray
- National Institute of Advanced Industrial Science and Technology, Ibaraki (Japan)
- Argonne National Lab. (ANL), Argonne, IL (United States)
Here, the eccentric needle motion has been regarded as an important cause of in-nozzle flow disturbances and hole-to-hole spray variations of modern fuel injectors. However, the experimental investigations on this subject have rarely been reported due to great difficulties in the direct measurements of eccentric needle motion and the flow characteristics of individual holes in an injection nozzle. In this study, the axial and eccentric needle motion and the ear-nozzle spray dynamics of 3-hole, 5-hole and 8-hole diesel injection nozzles were investigated in varied injection pressure conditions using an xray phase-contrast imaging technique. The eccentric needle motion and near-nozzle spray axial velocity showed temporal oscillations during the injection with different oscillation frequencies. The frequencies of these two oscillations were independent to the nozzle and injection pressure. To discuss the mutual dependency of these two oscillations, the time traces of the spray axial velocity were measured for individual holes. The results showed that the oscillation phase, frequency and amplitude of the spray axial velocity were almost identical for all holes, which indicated that the sac pressure variation rather than hole-to-hole flow variation can be the primary cause of the spray axial velocity oscillation by the eccentric needle motion. The adequacy of this consideration was thoroughly discussed using a mass balance model in the nozzle sac that predicted the sac pressure variation during an injection event.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- Isuzu Motors Ltd.; USDOE
- Grant/Contract Number:
- AC02-06CH11357
- OSTI ID:
- 1461350
- Journal Information:
- Fuel, Vol. 206, Issue C; ISSN 0016-2361
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Nozzle tip wetting in gasoline direct injection injector and its link with nozzle internal flow
|
journal | August 2019 |
Similar Records
Measurement of needle and armature dynamics in a gasoline direct injector by high-speed neutron imaging
Internal and near nozzle measurements of Engine Combustion Network “Spray G” gasoline direct injectors