Direct injection gasoline engines with autoignition combustion

Author(s):  
H. Zhao
Author(s):  
E Giannadakis ◽  
D Papoulias ◽  
A Theodorakakos ◽  
M Gavaises

The onset and development of cavitation in the annular needle seat passage of piezo-driven outward-opening pintle injector nozzles used with spray-guided direct-injection gasoline engines are studied using a Eulerian-Lagrangian computational fluid dynamics cavitation model. Cavitation is formed because of the fluid acceleration taking place at the needle sealing area and it has been found to be affected by its geometric details. Various submodels for nucleation and bubble formation, further bubble growth and collapse, as well as bubble break-up and transport are incorporated into the model. Qualitative model validation is performed against experimental data reported elsewhere in large-scale nozzle replicas, showing similar cavitation patterns to be formed. These consist of vapour pockets rather than a continuous vapour film and develop transiently in a rather chaotic manner around the circumferential needle sealing area, even under stationary geometry and fixed-flowrate conditions. Further transient effects associated with the fast opening and closing of the piezo-controlled needle valve are also presented.


2007 ◽  
Author(s):  
D. Papoulias ◽  
E. Giannadakis ◽  
N. Mitroglou ◽  
M. Gavaises ◽  
A. Theodorakakos

2013 ◽  
Author(s):  
Motoyuki Abe ◽  
Ehara Hideharu ◽  
Soma Masahiro ◽  
Tohru Ishikawa

Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 165 ◽  
Author(s):  
Enrico Sartoretti ◽  
Fabio Martini ◽  
Marco Piumetti ◽  
Samir Bensaid ◽  
Nunzio Russo ◽  
...  

A Gasoline Particulate Filter (GPF) can be an effective solution to abate the particulate matter produced in modern direct injection gasoline engines. The regeneration of this system is critical, since it occurs in oxygen deficiency, but it can be promoted by placing an appropriate catalyst on the filter walls. In this paper, a nanostructured equimolar ceria-praseodymia catalyst, obtained via hydrothermal synthesis, was characterized with complementary techniques (XRD, N2-physisorption, FESEM, XPS, Temperature Programmed Reduction, etc.) and its catalytic performances were investigated in low oxygen availability. Pr-doping significantly affected ceria structure and morphology, and the weakening of the cerium–oxygen bond associated to Pr insertion resulted in a high reducibility. The catalytic activity was explored considering different reactions, namely CO oxidation, ethylene and propylene total oxidation, and soot combustion. Thanks to its capability of releasing active oxygen species, ceria-praseodymia exhibited a remarkable activity and CO2-selectivity at low oxygen concentrations, proving to be a promising catalyst for coated GPFs.


MTZ worldwide ◽  
2013 ◽  
Vol 74 (3) ◽  
pp. 28-32 ◽  
Author(s):  
Axel Heinstein ◽  
Tilo Landenfeld ◽  
Martin Riemer ◽  
Thomas Sebastian

MTZ worldwide ◽  
2012 ◽  
Vol 73 (11) ◽  
pp. 10-14
Author(s):  
Jason King ◽  
Peter Feulner

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