A Study of Effects of Design Parameters on Transient Response and Injection Rate Shaping for a Common Rail Injector System

2001 ◽  
Author(s):  
Wanhua Su ◽  
Yang Wang ◽  
Tiejian Lin ◽  
Hui Xie ◽  
Yiqiang Pei ◽  
...  
Keyword(s):  
Transient Response ◽  
Injection Rate ◽  
Common Rail ◽  
Design Parameters ◽  
Rate Shaping ◽  
Common Rail Injector ◽  
Injector System

Investigation on Realizing Fuel Rate Shaping Using a Common Rail Injector

2003 ◽  
Author(s):  
Paolo Carlucci ◽  
Antonio Ficarella ◽  
Antonio Giuffrida ◽  
Rosario Lanzafame
Keyword(s):  
Modeling And Simulation ◽  
Computer Modeling ◽  
Injection Rate ◽  
Common Rail ◽  
Simulation Experiments ◽  
The Real ◽  
Rail Systems ◽  
Rate Shaping ◽  
Common Rail Injector ◽  
Fuel Rate

The present work deals with the first researches into the real capabilities of an electronically controlled injector for common rail systems in realizing a proper shaping of the fuel rate with particular reference to its rising profile. Injectors equipped with standard and geometrically modified control valves have been investigated in detail by means of computer modeling and simulation. Experiments have been carried out in order to validate the feasibility of such a shaping and the injection rate meter based on the method proposed by Bosch was used. The main result of this work is a noteworthy dependence of the fuel rate on geometrical modifications in the piloting stage of the injector, since a certain difference in the slope of the first part of the fuel rate has been attained. The injector model has been finally used to investigate further geometrical modifications to be realized in order to achieve the desired fuel rate shaping.

Understanding the Acoustic Oscillations Observed in the Injection Rate of a Common-Rail DI Diesel Injector

2012 ◽  
Author(s):  
Julien Manin ◽  
Alan Kastengren ◽  
Raul Payri
Keyword(s):  
Acoustic Analysis ◽  
Injection Rate ◽  
Point Of View ◽  
Common Rail ◽  
Acoustic Oscillations ◽  
Real Rate ◽  
The Real ◽  
Injection Process ◽  
Engine Combustion ◽  
Common Rail Injector

Measuring the rate of injection of a common-rail injector is one of the first steps for diesel engine development. At the same time, this information is of prime interest for engine research and modeling as it drives spray development and mixing. On the other hand, the widely used long-tube method provides results that are neither straightforward, nor fully understood. This study performed on a 0.09 mm axially drilled single-hole nozzle is part of the Engine Combustion Network (ECN) and aims at analyzing these features from an acoustic point of view to separate their impact on the real injection process and on the results recorded by the experimental devices. Several tests have been carried out for this study including rate of injection and momentum, X-ray phase-contrast of the injector and needle motion or injector displacement. The acoustic analysis revealed that these fluctuations found their origin in the sac of the injector and that they were the results of an interaction between the fluid in the chamber (generally gases) and the liquid fuel to be injected. It has been observed that the relatively high oscillations recorded by the long-tube method were mainly caused by a displacement of the injector itself while injecting. In addition, the results showed that these acoustic features also appear on the momentum flux of the spray which means that the real rate of injection should present such behavior.

scholarly journals Providing Boot-Type Injection Rate Shape by Electric Impulse Control of the Common Rail Injector

2020 ◽  
pp. 32-42
Author(s):  
A.Y. Dunin ◽  
M.G. Shatrov ◽  
L.N. Golubkov ◽  
A.L. Yakovenko
Keyword(s):  
Diesel Engines ◽  
Fuel Injection ◽  
Control Valve ◽  
Road Construction ◽  
Injection Rate ◽  
Common Rail ◽  
Oxide Content ◽  
Common Rail Injector ◽  
Electric Impulse ◽  
The Common

For effective reduction of noise level and nitrogen oxide content in exhaust fumes of diesel engines, multistage fuel injection is used in combination with control of the front edge shape of the main injection. At the Moscow Automobile and Road Construction State Technical University (MADI), a method of control of the injection rate shape using an electric impulse was proposed, which was applied to the electromagnet of the control valve of the injector of the common rail fuel system. A computational and experimental analysis of the possibility of boot-type injection rate shape was carried out. The studies involved three most used designs of the common rail injector (CRI): CRI 1 featuring a control valve with shut-off cone and piston; CRI 2 consisting of a flat-lock control valve and a needle, which does not overlap the drain when the needle is in the highest position; CRI 3 with an injector that partially overlaps the drain. It was established that friction in the control valve piston and the guide surface pair of CRI 1 complicated the implementation of the boot-type injection rate due to its smoothing. CRI 2 and CRI 3 provide boot-type injection rate at different pressures in the fuel accumulator. The CRI 3 example shows that the instability of fuel supply during boot-type injection rate is comparable with that of fuel pre-injection, which is widely used in the organization of the common rail diesel engines working process.

Dynamic rate shaping – one diesel common-rail injector for all combustion strategies

2019 ◽  
pp. 335-357
Author(s):  
David Needham ◽  
Dan Mellors ◽  
Tony Williams ◽  
Thomas Cawkwell ◽  
Simon Tullis
Keyword(s):  
Common Rail ◽  
Rate Shaping ◽  
Common Rail Injector

scholarly journals INFLUENCE OF PRESSURE OSCILLATIONS IN COMMON RAIL INJECTOR ON FUEL INJECTION RATE

2020 ◽  
pp. 579
Author(s):  
Mikhail G. Shatrov ◽  
Andrey U. Dunin ◽  
Pavel V. Dushkin ◽  
Andrey L. Yakovenko ◽  
Leonid N. Golubkov ◽  
...  
Keyword(s):  
Diesel Fuel ◽  
Fuel Injection ◽  
Injection Rate ◽  
Common Rail ◽  
Needle Valve ◽  
Rail Pressure ◽  
Pressure Oscillations ◽  
Multiple Injections ◽  
Double Injection ◽  
Common Rail Injector

Fuel injection causes considerable oscillations of fuel pressure at the injector inlet. One of the reasons is hydraulic impact when the needle valve closes. For multiple injections, the previous injections affect the following. As both the fuel pressure in rail pac and the injection rate grow, the oscillations increase. The pressure oscillation range at the common rail injector inlet at pac=1500 bar is up to 350 bar, and at the rail pressure pac=500 bar, the amplitude decreases to 80 bar. Physical properties of the fuel are also important. As the viscosity of the fuel increases, its hydraulic friction grows which results in a rapid damping of pressure oscillations. The data for an injector operating on sunflower oil is presented. As compared with diesel fuel, the oscillations range decreases from 400 to 250 bar at the same operating mode. The influence of the interval between the impulses of a double injection on the injection rate of the second fuel portion was investigated. Superposition of two waves during multiple injections may result in amplification and damping of the oscillations. Simulation was performed to estimate the influence of fuel type and time interval Δτ between control impulses of a double injection on the injection quantity of the second portion at pressures of 2000-3000 bar. When the rail pressure pac grows, the oscillations and their impact on the injection process increase. For diesel fuel at pressure of pac=2000 bar, the variation in injection rates of the second portion is 2.36-4.62 mg, and at pac=3000 bar – 1.58-6.63 mg.

Understanding the Acoustic Oscillations Observed in the Injection Rate of a Common-Rail Direct Injection Diesel Injector

2012 ◽  
Vol 134 (12) ◽  
Author(s):  
Julien Manin ◽  
Alan Kastengren ◽  
Raul Payri
Keyword(s):  
Acoustic Analysis ◽  
Direct Injection ◽  
Injection Rate ◽  
Common Rail ◽  
Acoustic Oscillations ◽  
Acoustic Features ◽  
Injection Process ◽  
Engine Combustion ◽  
Common Rail Injector ◽  
Engine Development

Measuring the rate of injection of a common-rail injector is one of the first steps for diesel engine development. The injected quantity as a function of time is of prime interest for engine research and modeling activities, as it drives spray development and mixing, which, in current diesel engines, control combustion. On the other hand, the widely used long-tube method provides results that are neither straightforward nor fully understood. This study, performed on a 0.09-mm axially drilled single-hole nozzle, is part of the Engine Combustion Network (ECN) and aims at analyzing the acoustic oscillations observed in the rate of injection signal and measuring their impact on the real injection process and on the results recorded by the experimental devices. Several tests have been carried out for this study, including rate of injection and momentum, X-ray phase-contrast of the injector, and needle motion or injector displacement. The acoustic analysis revealed that these fluctuations found their origin in the sac of the injector and that they were the results of an interaction between the fluid in the chamber (generally gases) or in the nozzle sac and the liquid fuel to be injected. It has been observed that the relatively high oscillations recorded by the long-tube method were mainly caused by a displacement of the injector itself while injecting. In addition, the results showed that these acoustic features are also present in the spray, which means that the oscillations make it out of the injector, and that this temporal variation must be reflected in the actual rate of injection.

scholarly journals Experimental study of the influence of pressure oscillations in common rail injector on fuel injection rate

2016 ◽  
pp. 304-304
Author(s):  
Mikhail Shatrov ◽  
Leonid Golubkov ◽  
Andrey Dunin ◽  
Pavel Dushkin ◽  
Andrey Yakovenko
Keyword(s):  
Experimental Study ◽  
Fuel Injection ◽  
Injection Rate ◽  
Common Rail ◽  
Pressure Oscillations ◽  
Common Rail Injector ◽  
Fuel Injection Rate

Parametric Characterization of High-Pressure Diesel Fuel Injection Systems

2003 ◽  
Vol 125 (2) ◽  
pp. 412-426 ◽  
Author(s):  
T.-C. Wang ◽  
J.-S. Han ◽  
X.-B. Xie ◽  
M.-C. Lai ◽  
N. A. Henein ◽  
...  
Keyword(s):  
Ambient Pressure ◽  
Injection Pressure ◽  
Injection Rate ◽  
Common Rail ◽  
Rail Pressure ◽  
Electronic Unit ◽  
Rate Shaping ◽  
Common Rail Pressure ◽  
Nozzle Configuration

The focus of the study described herein is the characterization of the high-pressure hydraulic electronic unit injector (HEUI) and of the electronic unit injector (EUI) diesel injection systems. The characterization items include injection pressure, injection rate, injector response time, needle lift, start up injection transient, and dynamic discharge coefficient of the nozzles. Macroscopic and microscopic spray visualizations were also performed. The effects of injection conditions and nozzle configurations on injection characteristics were reviewed. Nozzle sac pressure was measured to correlate with the up-stream injection pressure. A LabVIEW data acquisition and controls system was implemented to operate the injection systems and to acquire and analyze data. For an HEUI system, based on the results of the study, it can be concluded that common-rail pressure and length of the injection rate-shaping pipe determine the injection pressure, while the pressure rising rate and injection duration determine the peak injection pressure; it was also found that the nozzle flow area, common-rail pressure, and the length of the rate-shaping pipe are the dominating parameters that control the injection rate, and the rate shape is affected mainly by common-rail pressure, especially the pressure rising rate and length of the rate-shaping pipe. Both injection pressure and ambient pressure affected the spray tip penetration significantly. The penetration increased corresponding to the increase of injection pressure or decrease of ambient pressure. The variation of spray penetration depends on the type of injection system, nozzle configuration, and ambient pressure. The large penetration variation observed on the HEUI sprays could be caused by eccentricity of the VCO (valve-covered-orifices) nozzle. The variation of the mini-sac nozzle was 50% less than that of the VCO nozzle. The near-field spray behavior was shown to be highly transient and strongly depended on injector design, nozzle configuration, needle lift and oscillation, and injection pressure.

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