In “multijet” common rail (CR) diesel injection systems, when two consecutive injection current pulses approach each other, a merging of the two injections into a single one can occur. Such an “injection fusion” causes an undesired excessive amount of injected fuel, worsening both fuel consumption and particulate emissions. In order to avoid this phenomenon, lower limits to the dwell-time values are introduced in the control unit maps by a conservatively overestimated threshold, which reduces the flexibility of multiple-injection management. The injection fusion occurrence is mainly related to the time delay between the electrical signal to the solenoid and the nozzle opening and closure. The dwell-time fusion threshold was found to strongly decrease particularly with the nozzle closure delay. A functional dependence of the nozzle opening and closure delays on the solenoid energizing time and nominal rail pressure was experimentally assessed, and the injection temporal duration was correlated to the energizing time and rail pressure. A multijet CR injection-system mathematical model that was previously developed, including thermodynamics of liquids, fluid dynamics, mechanics of subsystems, and electromagnetism equations, was applied to better understand the cause and effect relationships for nozzle opening and closure delays. In particular, numerical results on the time histories of delivery- and control-chamber pressures, pilot- and needle-valve lifts, and mass flow rates through and holes were obtained and analyzed to highlight the dependence of nozzle opening and closure delays on injector geometric features, physical variables, and valve dynamics. The nozzle closure delay was shown to strongly depend on the needle dynamics. Parametric numerical tests were carried out to identify configurations useful for minimizing the nozzle closure delay. Based on the results of these tests, a modified version of a commercial electroinjector was built, so as to achieve effectively lower nozzle closure delays and very close sequential injections without any fusion between them.
Skip Nav Destination
Article navigation
March 2009
Research Papers
Numerical-Experimental Study and Solutions to Reduce the Dwell-Time Threshold for Fusion-Free Consecutive Injections in a Multijet Solenoid-Type CR System
Andrea E. Catania,
Andrea E. Catania
IC Engines Advanced Laboratory
, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
Search for other works by this author on:
Alessandro Ferrari,
Alessandro Ferrari
IC Engines Advanced Laboratory
, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
Search for other works by this author on:
Ezio Spessa
Ezio Spessa
IC Engines Advanced Laboratory
, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
Search for other works by this author on:
Andrea E. Catania
IC Engines Advanced Laboratory
, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
Alessandro Ferrari
IC Engines Advanced Laboratory
, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
Ezio Spessa
IC Engines Advanced Laboratory
, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, ItalyJ. Eng. Gas Turbines Power. Mar 2009, 131(2): 022804 (14 pages)
Published Online: December 22, 2008
Article history
Received:
April 14, 2007
Revised:
April 10, 2008
Published:
December 22, 2008
Citation
Catania, A. E., Ferrari, A., and Spessa, E. (December 22, 2008). "Numerical-Experimental Study and Solutions to Reduce the Dwell-Time Threshold for Fusion-Free Consecutive Injections in a Multijet Solenoid-Type CR System." ASME. J. Eng. Gas Turbines Power. March 2009; 131(2): 022804. https://doi.org/10.1115/1.2938394
Download citation file:
Get Email Alerts
Blade Excitation Alleviation of a Nozzleless Radial Turbine by Casing Treatment Based on Reduced Order Mode
J. Eng. Gas Turbines Power
Design And Testing of a Compact, Reverse Brayton Cycle, Air (R729) Cooling Machine
J. Eng. Gas Turbines Power
Experimental Study on Liquid Jet Trajectory in Cross Flow of Swirling Air at Elevated Pressure Condition
J. Eng. Gas Turbines Power
Related Articles
Development and Application of a Complete Multijet Common-Rail Injection-System Mathematical Model for Hydrodynamic Analysis and Diagnostics
J. Eng. Gas Turbines Power (November,2008)
Numerical Analysis and Experimental Investigation of a Common Rail-Type Diesel Injector
J. Eng. Gas Turbines Power (October,2004)
Experimental Validation of a Common-Rail Injector Model in the Whole
Operation Field
J. Eng. Gas Turbines Power (April,2007)
Determination of Flow Rate Characteristics of Pneumatic Solenoid Valves Using an Isothermal Chamber
J. Fluids Eng (March,2004)
Related Proceedings Papers
Related Chapters
A Simple Carburetor
Case Studies in Fluid Mechanics with Sensitivities to Governing Variables
Internal and Near Nozzle Flow Simulations of Gasoline Multi-Hole Injector (ECN Spray G) with Transient Needle Motion
Proceedings of the 10th International Symposium on Cavitation (CAV2018)
Antilock-Braking System Using Fuzzy Logic
International Conference on Mechanical and Electrical Technology, 3rd, (ICMET-China 2011), Volumes 1–3