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Reduction of pollutant emissions by developing a variable valve timing system in a direct injection diesel engine using computational fluid dynamics modeling
Author(s) -
Ashkezari Abbas Zarenezhad,
Nezhad Alireza Hossein,
Farahat Said
Publication year - 2016
Publication title -
environmental progress and sustainable energy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.495
H-Index - 66
eISSN - 1944-7450
pISSN - 1944-7442
DOI - 10.1002/ep.12371
Subject(s) - pollutant , reduction (mathematics) , diesel fuel , variable (mathematics) , computational fluid dynamics , diesel engine , environmental science , valve timing , automotive engineering , system dynamics , computer science , engineering , chemistry , aerospace engineering , mathematics , internal combustion engine , organic chemistry , mathematical analysis , geometry , artificial intelligence
In this work, the fluid flow in a direct injection compression ignition engine and its effects on performance and pollutant emissions are studied by using computational fluid dynamics simulation through developing of variable valve timing system by combination of the optimum valve lifting and late inlet valve closing (LIVC) strategies. For this purpose, an improved version of ECFM‐3Z combustion model coupled with advanced models for NO x and soot formation was used to predict and simulate the combustion characteristics. First, the calculated in‐cylinder pressure, heat‐release rate, soot, and NO x were compared with experimental data and good agreement was obtained. To improve the performance and reduce the emission, various angles of LIVC and different types of valve lifting were compared with those of engine basic mode, and then optimum inlet valve closing (IVC) angle and optimum valve lift were determined. Results showed that in constant opening duration of the inlet valve, the volumetric efficiency increases by increasing the valve lift. In addition, the 25% increase of valve lift relative to basic mode along with optimized IVC angle of 70° crack angle after bottom dead center improves volumetric efficiency and brake power, and reduces considerably soot, NO x , and brake‐specific fuel consumption, while CO emission is increased slightly. © 2016 American Institute of Chemical Engineers Environ Prog, 35: 1430–1440, 2016