MEMS Invited Research Lecture Series lecture 3
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Who this event is for
El19a, EL Building, Wheatley Campus
'Looking inside the Jaguar AJ-V8 Gen III Engine'. Professor Richard Stone, Head of the Internal Combustion Engines Group and Professor in Engineering Science at the University of Oxford, delivers the third in this series of invited research lectures.
Looking Inside the Jaguar AJ-V8 Gen III 5 Litre Engine
The Jaguar AJ-V8 Gen III engine uses a spray-guided direct injection combustion system, and the engine with optical access has been used to study:
· Spray formation – using Mie scattering
· Mixture distribution using Planar Laser Induced Fluorescence
· Three colour pyrometry to provide data on combustion temperature and soot formation.
Also important are the emissions of particulate matter, and the number limit on the particulate matter emissions that will be in Euro VI is a major challenge for spray-guided direct injection combustion systems. The effect of fuel composition is illustrated by considering the influence of ethanol when added to gasoline.
Fast catalyst light-off is essential for engines to meet drive cycle emissions legislation, and light-off can be accelerated by operating the engine with a very retarded ignition timing, such that the engine is essentially idling (no net power output), yet the inlet manifold pressure can be very high (0.5 bar or higher). The high fuel flow rate with very little work and a short time for heat transfer leads to a very high exhaust temperature. However, this often leads to low combustion stability, but split injection can be used to provide a locally rich mixture at the spark plug at ignition. However, the timing of the injection is critical if misfiring cycles are to be resolved. To elucidate the different misfiring mechanisms, measurements have been made of: spark parameters, in-cylinder pressure, hydrocarbon concentrations in the region of the spark plug, along with chemiluminescence measurements and high speed imaging of the fuel spray and combustion.
Richard Stone is a Professor in Engineering Science at the Department of Engineering Science at Oxford. He was appointed to a lectureship in Oxford in 1993, and for 11 years prior to that he was a lecturer/senior lecturer at Brunel University. His main interest is combustion in spark ignition engines, but he also has interests in in-cylinder heat transfer, the measurement of laminar burning velocities under wide ranging temperatures, pressures and compositions, and is undertaking a longitudinal study of vehicle technology. He has written over 100 papers, mostly in the area of engine combustion and instrumentation. He is well known for his book ‘Introduction to Internal Combustion Engines’, now in its 4th edition.