scholarly journals Internal Flow and Cavitation in a Multi-Hole Injector for Gasoline Direct-Injection Engines

2007 ◽  
Author(s):  
J. M. Nouri ◽  
N. Mitroglou ◽  
Y. Yan ◽  
C. Arcoumanis
Keyword(s):  
Direct Injection ◽  
Internal Flow ◽  
Gasoline Direct Injection ◽  
Direct Injection Engines

scholarly journals Collaborative investigation of the internal flow and near-nozzle flow of an eight-hole gasoline injector (Engine Combustion Network Spray G)

2020 ◽  
pp. 146808742091844
Author(s):  
Chinmoy K Mohapatra ◽  
David P Schmidt ◽  
Brandon A Sforozo ◽  
Katarzyna E Matusik ◽  
Zongyu Yue ◽  
...  
Keyword(s):  
Direct Injection ◽  
Internal Flow ◽  
Gasoline Direct Injection ◽  
Two Phase ◽  
Direct Injection Engines ◽  
Fuel Injectors ◽  
Engine Combustion ◽  
Injector Flows ◽  
Eulerian Modeling ◽  
The Impact

The internal details of fuel injectors have a profound impact on the emissions from gasoline direct injection engines. However, the impact of injector design features is not currently understood, due to the difficulty in observing and modeling internal injector flows. Gasoline direct injection flows involve moving geometry, flash boiling, and high levels of turbulent two-phase mixing. In order to better simulate these injectors, five different modeling approaches have been employed to study the engine combustion network Spray G injector. These simulation results have been compared to experimental measurements obtained, among other techniques, with X-ray diagnostics, allowing the predictions to be evaluated and critiqued. The ability of the models to predict mass flow rate through the injector is confirmed, but other features of the predictions vary in their accuracy. The prediction of plume width and fuel mass distribution varies widely, with volume-of-fluid tending to overly concentrate the fuel. All the simulations, however, seem to struggle with predicting fuel dispersion and by inference, jet velocity. This shortcoming of the predictions suggests a need to improve Eulerian modeling of dense fuel jets.

Numerical Simulation of Transient Flow Inside Nozzle on Gasoline Direct Injection Engine

2012 ◽  
Vol 466-467 ◽  
pp. 1237-1241
Author(s):  
Yan Hua Wang ◽  
Shi Chun Yang ◽  
Yun Qing Li
Keyword(s):  
Kinetic Energy ◽  
Transient Flow ◽  
Direct Injection ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Turbulence Kinetic Energy ◽  
Gasoline Direct Injection ◽  
Injection Hole ◽  
Gasoline Direct Injection Engine ◽  
Nozzle Configuration

To achieve transient flow characteristics at exit of nozzle orifice on gasoline direct injection engine, two phase Euler-Euler schemes was used to simulate the internal flow of the swirl nozzle. Different flow characteristics were calculated in the simulation. Different kinds of nozzle configuration were studied. Cavitaion and swirl flow occured in the nozzles. Injection hole configuration matters more than area variation of swirl tangential slot to discharge coefficient of the studied nozzle. Discharge coefficient changes a little along the injection hole length. The area of the swirl tangrntial slot plays an important throttling action in nozzle internal flow. Smaller area of swirl tangential slot generates larger degree cavitation but smaller mean injection velocity. Turbulence kinetic energy changes with the time of cavitation and swirl field occurring and the nozzle configuration. Before the appearance of cavitation, smaller inclination angle of orifice can generate more turbulence kinetic energy. After that moment, turbulence kinetic energy varies with different configuration. Along injection hole length, turbulence kinetic energy obviously varies. These flow characteristics affect primary atomization and will be as input for next spray simulation. They are also applied to design reference for injection nozzle.

Fuel Pressure Increase up to 50 MPa for Gasoline Direct-injection Engines

MTZ worldwide ◽  
2018 ◽  
Vol 79 (7-8) ◽  
pp. 50-55 ◽  
Author(s):  
Felix Eitel ◽  
Jörg Schäfer ◽  
Achim Königstein ◽  
Christof Heeger
Keyword(s):  
Direct Injection ◽  
Gasoline Direct Injection ◽  
Pressure Increase ◽  
Direct Injection Engines

Simulation of Coarse Droplet and Liquid Column Formed around Nozzle Outlets Due to Valve Wobble of a Gasoline Direct Injection Injector

2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Eiji Ishii ◽  
Yoshihito Yasukawa ◽  
Kazuki Yoshimura ◽  
Kiyotaka Ogura
Keyword(s):  
Surface Tension ◽  
Particulate Matter ◽  
Direct Injection ◽  
Gasoline Direct Injection ◽  
Fuel Spray ◽  
Direct Injection Engines ◽  
Fuel Injectors ◽  
Multiple Injections ◽  
Fuel Mixtures ◽  
Opening And Closing

The generation of particulate matter (PM) is one problem with gasoline direct-injection engines. PM is generated in high-density regions of fuel. Uniform air/fuel mixtures and short fuel-spray durations with multiple injections are effective in enabling the valves of fuel injectors not to wobble and dribble. We previously studied what effects the opening and closing of valves had on fuel spray behavior and found that valve motions in the opening and closing directions affected spray behavior and generated coarse droplets during the end-of-injection. We focused on the effects of valve wobbling on fuel spray behavior in this study, especially on the behavior during the end-of-injection. The effects of wobbling on fuel spray with full valve strokes were first studied, and we found that simulated spray behaviors agreed well with the measured ones. We also studied the effects on fuel dribble during end-of-injection. When a valve wobbled from left to right, the fuel dribble decreased in comparison with a case without wobbling. When a valve wobbled from the front to the rear, however, fuel dribble increased. Surface tension significantly affected fuel dribble, especially in forming low-speed liquid columns and coarse droplets. Fuel dribble was simulated while changing the wetting angle on walls from 60 to 5 deg. We found that the appearance of coarse droplets in sprays decreased during the end-of-injection by changing the wetting angles from 60 to 5 deg.

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