Interaction of multiple linear helical modes in the turbulent flow field of an industrial fuel injection system

2022 ◽  
Author(s):  
Lukas Moczarski ◽  
Nicholas C. Treleaven ◽  
Kilian Oberleithner ◽  
Simon Schmidt ◽  
André Fischer ◽  
...  
Keyword(s):  
Flow Field ◽  
Turbulent Flow ◽  
Fuel Injection ◽  
Injection System ◽  
Fuel Injection System ◽  
Turbulent Flow Field

Assessment of large-eddy simulation feasibility in modelling the unsteady diesel fuel injection and mixing in a highspeed direct-injection engine

2009 ◽  
Vol 223 (8) ◽  
pp. 1033-1048 ◽  
Author(s):  
K Jagus ◽  
X Jiang ◽  
G Dober ◽  
G Greeves ◽  
N Milanovic ◽  
...  
Keyword(s):  
Flow Field ◽  
Turbulent Flow ◽  
Diesel Fuel ◽  
Fuel Injection ◽  
Direct Injection ◽  
Mesh Size ◽  
Eddy Simulation ◽  
Injection Process ◽  
Mesh Density ◽  
Turbulent Flow Field

This paper aims to assess the feasibility of largeeddy simulation LES as applied to a real engine configuration. Two cases of LES were performed together with a reference Reynoldsaveraged NavierStokes RANS simulation to study their performances in the prediction of the fuel injection and mixing in a highspeed directinjection diesel engine. In addition, sensitivity of the LES results with respect to mesh resolution was investigated, as LES requires a higher mesh density and the filtering process depends on the mesh size. The LES meant that detailed information could be obtained on the fuel spray development and turbulent flow field that was not possible to capture using the RANS modelling approach. It was found that the LES captures flow structures that have a pronounced impact on the prediction of the fuel injection and mixing. Highresolution LES predicted higher liquid and vapour penetration into the cylinder, which is in better agreement with the experimental data obtained at Delphi Diesel Systems than is the RANS prediction. It was also shown that using a finer mesh in LES yields improvements in turbulent flow field prediction, at the same time reducing contribution of the modelled part of the turbulent kinetic energy. Overall, it was proved that LES is a superior alternative to the traditional RANS approach for turbulent twophase flows encountered in diesel fuel injections where flow unsteadiness is prominent. Improved predictions obtained from an advanced LES can subsequently enhance the understanding of the fuel injection process and assist the engine experimentation and design.

Study on Wear-Preventing of Needle Valve in Fuel Injection System Mounted on DME Engine

2011 ◽  
Vol 228-229 ◽  
pp. 1057-1062
Author(s):  
Xin Rong Wen ◽  
Guang De Zhang ◽  
Wei Hua Wang ◽  
Xie Lu ◽  
Sun Jing
Keyword(s):  
Dynamic Stability ◽  
Structural Design ◽  
Fuel Injection ◽  
Dynamic Instability ◽  
Calculation Model ◽  
The Other ◽  
Injection System ◽  
Needle Valve ◽  
Fuel Injection System ◽  
Theoretical Support

The purpose of this paper is to provide theoretical support for the structural design to prevent the wear of needle. The actual wear of the orientation part of the needle in scrapped needles was researched. The presented results showed that the main reason to the wear of the orientation part of needle was the dynamic instability and the abrasives enter into the surface of orientation part which increases the wear, and that the calculation model of dynamic stability was proposed to prevent the wear of needle. This model was a pressure rod, one end of which was fixed, the other was free, and the two ends were pressed on axial force which changes with time. Besides, the classic formula of dynamic stability of pressure rod was changed rationally, so as to correspond with the calculation model. It will play a part in preventing the wear of needle.

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