Trucking to a cleaner, greener future

Scientists at the University of Brighton are leading industry developments to create cleaner, more efficient diesel engines, and their work on heavy-duty engines is being adopted by leading manufacturers across the world.

When fuel is burnt in a diesel engine, typically a third of the energy produced is used for propulsion, a third is lost to cooling and a third is lost through the exhaust: most truck engines are around 38 per cent efficient at best. Automotive engineers based at the University of Brighton's Centre for Automotive Engineering are working with leading fuel injection system manufacturers to push the boundaries of high-pressure fuel injection technologies, reducing noxious emissions without a fuel economy penalty.

"Trucks have an important attribute in that their duty cycles – the way in which they're used – have long periods of steady engine use on motorways and long distance journeys," said Professor Morgan Heikal, Ricardo Professor of Automotive Engineering. "There are big benefits attached to increasing their efficiency, especially since heavy-duty diesel engines produce between 40 and 50 per cent of all road transport emissions."

Our commercial vehicle revenue was improved significantly due to our ability to use the results at Brighton, and Delphi now supply the FIE systems used in this research to a number of heavy duty engine makers.

Dr Simon Edwards, Global Director Technology, Ricardo UK Ltd

The influence of compression ratio and the interaction between fuel spray and piston bowl have been the subject of a Brighton-led project funded by the DTI with Ricardo UK, Ford and Imperial College, London. The university?s scientists developed key sub-systems for a low-emission, efficient, cost-effective and durable heavy-duty truck engine, aiming at 'near zero' emissions. Engineers showed that early pilot injections improved the trade-off between Particulate Matter (PM) and Nitrogen Oxides (NOx) at 25 per cent engine load, and that post-injections reduced soot emissions by a factor of at least two at 50 per cent load.

"Today's injectors are capable of very fine control and exceptionally quick response," said Professor Heikal. "Where we once used one main injection of fuel, with a pre- and a post-injection, we now typically use at least five or six pulses of injection to shape the heat release, which is central to improved efficiency. Our latest research is focusing on waste heat recovery, aiming for more efficient total thermal management. Alongside this, we?re looking at a constant increase in the accuracy of fuel injection control using state-of-the-art technology."

A £7million government grant has been awarded for the development of a new engineering centre of excellence

Another industrial partner, Delphi, is a leading global supplier of automotive technologies with technical and manufacturing centres in 30 countries. Using developments pioneered at Brighton, engines at Delphi have shown consistent PM reductions of between 20 and 50 per cent, using injection pressures up to 3,000 bar and multiple fuel injections. "Achieving this at an affordable cost meant taking a new approach to the design and manufacture of many of the components," said David Draper, Engineering Director of Delphi Diesel Systems. "The partnership with our manufacturing specialists was central to the success of the program and has allowed us to make incremental improvements in a number of areas, providing what we believe is now the most efficient system available."

This research has recently been boosted with a ?7m government grant towards a new engineering centre of excellence. This will enhance research opportunities and enable the search for a near-zero emissions internal combustion engine. Professor Neville Jackson, Ricardo's Chief Technology and Innovation Officer, said: "This new initiative builds upon the highly successful collaboration, of over 20 years standing, between Ricardo and the university on next-generation clean combustion technology and high fuel efficiency engine research."