Combustion Concepts for Sustainable Premium Vehicles

Overview

Collaboration between the four universities (Leeds, Loughborough, Oxford and UCL) with co-ordination by Jaguar and additional support from Shell, will lead to a 'Virtual Centre of Excellence' that exploits the complementary strengths of the four universities in gasoline engine combustion. The same hardware will be used at each institution so as to assure maximum value from all data. In the past data has been of less use since the measurements have been obtained using different engine hardware and fuels. This project is intended to be part of a much longer term project that will embrace novel gasoline combustion technologies, but initially the project will focus on direct injection spark ignition (DISI) engines and the factors that determine the cycle-by-cycle variations in combustion. This understanding will facilitate wider operating envelopes for stratified charge combustion systems, so as to simultaneously reduce fuel consumption and emissions.

The influencing mechanisms behind cycle-by-cycle variations, and effective methods for their control have not yet been satisfactorily defined, but this is essential if future engine technologies are to meet their full potential. Furthermore, it is believed that the trend for the next generation of engine technology will be towards an on-board artificial intelligence controlled system, which will be based on cycle-by-cycle engine operation. Developing an understanding and control of the cyclic variability is an enabling step in this development process and can only be achieved by a specifically focused and structured programme.

Timescale

Start : 1st October 2003. Ends : 30th September 2007.

Involved Parties

Group : C.R. Stone, R. Stevens, H. Ma, P. Ewart, Y. Arita
Project Support : EPSRC, Jaguar Cars, Shell.

Pyrometry Results

The following video sequences were obtained from the Jaguar single cylinder engine with optical access installed in the engines lab in the Department of Engineering Science and are typical of the work being undertaken on this project. Use of a transparent piston with a hemispherical concave lower surface allowed use of full-bore optics. Pyrometry is then used to provide temperature and KL (soot) data for each frame. All videos are in .avi format.

PLIF Results

Planar Laser Induced Fluorescence (PLIF) can be used to determine the distribution of air-fuel ratio across the cylinder on a crank angle resolved basis. A laser sheet is formed and passed through the piston window. Fluroescence of tracers in the fuel is detected by an intensified CCD camera looking through a pent roof window. All videos are in .wmv format.