Combustion processes in a diesel engine

Crua, Cyril (2002) Combustion processes in a diesel engine Doctoral thesis, University of Brighton.


Download (6MB) | Preview


The effects of in-cylinder and injection pressures on the formation and autoignition of diesel sprays at realistic automotive in-cylinder conditions was investigated. A two-stroke diesel Proteus engine has been modified to allow optical access for visualisation of in-cylinder combustion processes. Various optical techniques were used to investigate the combustion processes. These include high-speed video recording of the liquid phase, high-speed schlieren video recording of the vapour phase and laser-induced incandescence for soot imaging. The spray cone angle and penetration with time data extracted from photographic and high-speed video studies are presented. The effects of droplet evaporation, breakup and air entrainment at the initial stage of spray penetration were studied theoretically using three models. It was found that the predictions of the model combining bag breakup and air entrainment are in good agreement with the experimental measurements. Spray autoignition was investigated using video, in-cylinder pressure, and schlieren recordings. Pseudo three-dimensional visualisation of the autoignition was achieved by simultaneous use of two high-speed video cameras at right angles to each other. The effects of elevated injection and in-cylinder pressures on the ignition delay and ignition sites have been investigated. Laser-induced incandescence was performed to obtain maps of soot concentration for a range of engine conditions. The influence of in-cylinder and injection pressures on soot formation sites and relative soot concentration has been studied. The work has been mainly focused on the specificities of soot formation under extreme in-cylinder conditions.

Item Type: Thesis (Doctoral)
Additional Information: Awarded a 2003 Richard Way Memorial Prize for the best PhD Thesis on Automotive Engineering, by the UnICEG (UK Universities' Internal Combustion Engine Group). © Attention is drawn to the fact that copyright of this thesis rests with its author. This copy of the thesis has been supplied on condition that anyone who consults it is understood to recognise that its copyright rests with its author and that no quotation from the thesis and no information derived from it may be published without the prior written consent of the author.
Uncontrolled Keywords: Diesel atomisation; autoignition; combustion; soot; laser-induced incandescence; LII
Subjects: H000 Engineering > H300 Mechanical Engineering > H330 Automotive Engineering
Faculties: Faculty of Science and Engineering > School of Computing, Engineering and Mathematics > Engineering and Product Design Research > Automotive Engineering
Depositing User: Dr Cyril Crua
Date Deposited: 19 Jan 2007
Last Modified: 16 Mar 2015 15:42

Actions (login required)

View Item View Item


Downloads per month over past year