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Impact of injector deposits and spark plug gap on engine performance and emissions

Badawy, Tawfik (2018)
Ph.D. thesis, University of Birmingham.

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This research has focused on obtaining a comprehensive understanding of gasoline direct injector coking effects on fuel injection, engine performance and emissions. The impact of spark plug electrode gap on flame kernel development, engine performance, and emissions was also investigated. In this study, the deposit build-up inside the injector nozzles and on the injector tips reduced the plume cone angle, while it increased the plume penetration length, plume separation angles, mean droplet velocity and size for the coked injector. The coked injectors showed a higher degree of inhomogeneity and poorer repeatability in mixture preparation. The combustion analysis demonstrated that the coked injectors showed lower load and lower combustion stability, compared with the clean injector under the same operating conditions. The increase of the spark plug gap resulted in an increase for the flame kernel growth area. The maximum in-cylinder pressure, turbulent flame speed, heat release rate and the mass fraction burned increased with the spark plug gap. The engine output increased slightly and the combustion process became more stable due to the reduction in cyclic variations as the spark plug gap increased. With the maximum spark plug gap, the engine produced minimum hydrocarbon emissions and particulate number concentration.

Type of Work:Ph.D. thesis.
Supervisor(s):Xu, Hongming and Wyszynski, Miroslaw L.
School/Faculty:Colleges (2008 onwards) > College of Engineering & Physical Sciences
Department:School of Mechanical Engineering
Additional Information:

Publications arising from thesis:

Assessment of gasoline direct injector fouling effects on fuel injection, engine performance and emissions, Tawfik Badawy, Mohammadreza Anbari Attar, Hongming, and Akbar Ghafourian, Applied Energy, 220, 2018, 351-374.

Investigation of injector coking effects on spray characteristic and engine performance in gasoline direct injection engines, Tawfik Badawy, Mohammadreza Anbari Attar, Peter Hutchins, Hongming Xu, Jens Krueger Venus, and Roger Cracknell, Applied Energy, 220, 2018, 375-394.

Impact of spark plug gap on flame kernel propagation and engine performance, Tawfik Badawy, Bao Xiuchao, and Hongming Xu, Applied Energy, 191, 2017, 311-327.

Investigation of deposit effect on multi-hole injector spray characteristics and air/fuel mixing process, Bo Wang, Tawfik Badawy, Yizhou Jiang, Hongming Xu, and Akbar Ghafourian, Fuel, 191, 2017, 10-24.

Numerical analysis of deposit effect on nozzle flow and spray characteristics of GDI injectors, Bo Wang, Yizhou Jiang, Peter Hutchins, Tawfik Badawy, and Hongming Xu, Applied Energy, 191, 2017, 350-362.

Experimental characterization of closely coupled split isooctane sprays under flash boiling conditions, Ziman Wang, Tawfik Badawy, Bo Wang, Yizhou Jiang, and Hongming Xu, Applied Energy, 183, 2017, 189-219.

The influence of flash boiling conditions on spray characteristics with closely coupled split injection strategy, Ziman Wang, Changzhao Jiang, Hongming Xu, Tawfik Badawy, Bo Wang, and Yizhou Jiang, Applied Energy, 187, 2017, 523-533.

Laminar burning characteristics of ethyl propionate, ethyl butyrate, ethyl acetate, gasoline and ethanol fuels, Tawfik Badawy, Jake Williamson, and Hongming Xu, Fuel, 183, 2016, 627-640.

Microscopic characterization of isooctane spray in the near field under flash boiling condition, Ziman Wang, Bo Wang, Changzhao Jiang, Hongming Xu, and Tawfik Badawy, Applied Energy, 180, 2016, 598-606.

Study of near nozzle spray characteristics of ethanol under different saturation ratios, Bo Wang, Tawfik Badawy, Yanfei Li, Hongming Xu, Yizhou Jiang, and Xinyu Zhang, SAE Technical Paper, 2016, No. 2016-01-2189.

Subjects:TJ Mechanical engineering and machinery
Institution:University of Birmingham
ID Code:8187
This unpublished thesis/dissertation is copyright of the author and/or third parties. The intellectual property rights of the author or third parties in respect of this work are as defined by The Copyright Designs and Patents Act 1988 or as modified by any successor legislation. Any use made of information contained in this thesis/dissertation must be in accordance with that legislation and must be properly acknowledged. Further distribution or reproduction in any format is prohibited without the permission of the copyright holder.
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