ALAC (Advanced Laser Applications Conference and Exposition) 2005 Proceedings Volume 3: Product Engineering & Manufacturing. Pages 104-111 ISBN: 1554-2971
Robert Dodd(1), Jack Mullett(1), Stephan Carroll (1), Geoffrey Dearden (1), Tom Shenton(1), Kenneth Watkins(1), Georgios Triantos(1), Steve Keen(2).
1) The University of Liverpool (Dept. of Engineering, PO Box 147, Brownlow Hill, Liverpool, L69 3GH, UK) email:email@example.com
2) GSI Lumonics (Cosford Lane, Swift Valley Rugby, Warwickshire, CV21 1QN, UK)
Abstract: The use of laser energy to ignite gas and liquid based fuel-air mixtures has been the subject of a number of studies and laboratory experiments at a fundamental level over the past 30 years. Yet, the practical implementation of this laser application has still to be fully realised in a real world engine environment. Laser Ignition (LI), as a replacement for Spark Ignition (SI) in the internal combustion (IC) engines of automotive vehicles, could offer several potential advantages in terms of extending lean burn capability, reducing the cyclic variations between combustion cycles and reducing the overall ignition package costs, weight and energy requirements. The continued development of increasingly compact and efficient laser sources and new associated laser beam delivery techniques have provided the basis for significant steps forward in research towards practical proof-of-concept demonstration of LI in engines for automotive vehicles. This paper reports on some results of research recently undertaken at the University of Liverpool, in which a Q-switched Nd:YAG laser operating at 1064 nm wavelength has been used to successfully ignite and run (for extended periods) one cylinder of a 4-cylinder internal combustion (IC) test engine. The variation of several laser parameters and their effect on the engine performance are reported; namely, pulse energies of 5-20 mJ, pulse lengths of 6-15 ns and focused beam waist diameters at the combustion point of 40-100 m µ . Engine performance was measured in terms of changes in Coefficient of Variation (COV) in both Indicated Mean Effective Pressure (IMEP) and the Peak Cylinder Pressure Position (PPP).