scholarly journals Experimental investigation on lubricity of 2,5-dimethylfuran blends

2012 ◽  
Vol 148 (1) ◽  
pp. 2-10
Author(s):  
Farshad ESLAMI ◽  
Miroslaw WYSZYNSKI ◽  
Athanasios TSOLASKIS ◽  
Hongming XU ◽  
Shahrouz NOROUZI ◽  
...  
Keyword(s):  
Alternative Fuels ◽  
Direct Injection ◽  
Injection Pressure ◽  
Spark Ignition Engines ◽  
Test Rig ◽  
High Injection ◽  
High Injection Pressure ◽  
Ethanol Blends ◽  
Fuel Lubricity

Spark ignition engines fuelled with alternative fuels are the topic of many studies. As alternatives for gasoline, ethanol and recently 2,5-dimethylfuran (DMF) have been investigated for their different properties. Lubricity analysis of fuels in fuel systems is vital because of the lubricating role of fuel. Lubricity of gasoline and its alternatives became important since introduction of direct-injection gasoline fuel pump with high injection pressure becoming closer to diesel pumps. Therefore, this work examines the lubricity properties of gasoline and its blends with alternative fuels using a HFRR lubricity test rig. Results showed that DMF as an additive to gasoline improved the lubricity of blend; this effect was increasing with the percentage of DMF. These results can be compared with DMF-ethanol blends which displayed the same pattern but with lower enhancing role of DMF. The DMF fuel was kept in storage for seven months and then the same experiments were repeated (DMF Ageing). Smaller wear scar and better lubricity effects were achieved by using the aged DMF. These results highlight the potential of DMF to become an additive for gasoline and its alternatives.

Effect of ultra-high injection pressure up to 50 MPa on macroscopic spray characteristics of a multi-hole gasoline direct injection injector fueled with ethanol

2017 ◽  
Vol 232 (8) ◽  
pp. 1092-1104 ◽  
Author(s):  
Xiang Li ◽  
Yi-qiang Pei ◽  
Jing Qin ◽  
Dan Zhang ◽  
Kun Wang ◽  
...  
Keyword(s):  
High Speed ◽  
Direct Injection ◽  
Cone Angle ◽  
Injection Pressure ◽  
Fuel Mixture ◽  
Gasoline Direct Injection ◽  
Spray Characteristics ◽  
High Injection ◽  
High Injection Pressure ◽  
Wall Impingement

This research systematically studied the effect of injection pressure on macroscopic spray characteristics of a five-hole gasoline direct injection (GDI) injector fueled with ethanol, especially under ultra-high injection pressure up to 50 MPa. The front and side views of sprays were photographed by the schlieren method using a high-speed camera. Various parameters, including spray development stages, cone angle, penetration, area and irregular ratio, were fully analyzed to evaluate macroscopic characteristics of the whole spray and spray core with varying injection pressure. The results demonstrated that the effect of ultra-high injection pressure on macroscopic spray characteristics was significant. As injection pressure increased from 10 MPa to 50 MPa, the occurrence time of branch-like structure decreased; the cone angle increased little; the area increased significantly; the area ratio dropped by 6.4 and 5.8 percentage points on average for the front view and side view spray, respectively. There was a significant increase in the trend for penetration as the injection pressure rose from 10 MPa to 30 MPa. However, this trend became weak when the injection pressure further increased. The penetration ratio under ultra-high injection pressure was slightly higher than it was under 10 or 20 MPa. Ultra-high injection pressure would not obviously raise the possibility of spray/wall impingement, but led to the impingement quantity increasing to some extent. Increasing injection pressure could enhance the vortex scale, finally resulting in better air/fuel mixing quality. Ultra-high injection pressure was a potential way to improve air/fuel mixture homogeneity for a GDI injector fueled with ethanol.

Actual Tip Layout and Off-Axis Stroke in Nozzle Flow Modeling Under Ballistic Needle Displacement

2012 ◽  
Author(s):  
Giancarlo Chiatti ◽  
Fulvio Palmieri
Keyword(s):  
Injection Pressure ◽  
Operating Conditions ◽  
Cfd Modeling ◽  
Nozzle Flow ◽  
Flow Modeling ◽  
Split Injection ◽  
Fuel Flow ◽  
High Injection ◽  
High Injection Pressure

The injection of small amount of diesel fuel is mainly achieved through the shortening of energizing signal. Consequently, in such injection phases, the needle does not reach the mechanical stroke-end and its displacement may be defined as ballistic. By means of a detailed 3D-CFD modeling, the behavior of nozzle flow is investigated under typical pilot/split injection conditions, namely high injection pressure and low needle lift. The investigation focuses on the effects of the restricted flow passage on fuel flow at hole inlets. Once the modeling details are described, the influence of different elements on the internal fuel flow is shown and discussed, pointing out the role of different driving factors; investigations take into account actual injector tip layouts and the response to the needle off-axis operating conditions. Results are presented highlighting the flow pattern features within the nozzle and their reflects on the hole-to-hole differences.

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