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Dr Graham Wigley
T: 01509 227271
E: G.Wigley@lboro.ac.uk
The automobile industry is under pressure. Governments are driving through legislation that demands cleaner, green vehicles, while motorists want fuel economy without sacrificing performance. But can you ever really satisfy green groups and the car buyer?
Alison Laing talked with Dr Graham Wigley of Loughborough's Aeronautical and Automotive Engineering department and discovered a high technology research project which claims to do just that.
Loughborough University's Dr Graham Wigley is a great believer in teamwork - in bringing together the best brains and the cleverest kit, to create cutting-edge technologies.
And his recent collaboration has certainly paid off. Working alongside colleagues and students at Loughborough, with University College London (UCL), and experts in the automotive industry, such as Lotus and Siemens VDO (now Continental Powertrain), Dr Wigley and the team have achieved award-winning results.
Their three-year research programme, called Project HOTFIRE, produced a gasoline direct injection (GDI) engine with variable valve timing that reduces emissions, while delivering up to 15 per cent greater fuel efficiency. It cost around £500,000 to develop, and was funded by the Engineering and Physical Sciences Research Council (EPSRC), plus cash contributions from industry.
Project HOTFIRE involved Lotus Engineering building a pair of matched single cylinder
engines. An optical engine was based at Loughborough and a thermodynamic engine,
based at UCL. Complementary research programmes were performed at each university.
Loughborough's optical research engine had a unique, transparent silica cylinder liner and a sapphire 'window' in the piston. This allowed the in-cylinder combustion to be observed. Laser diagnostics were used to measure air/fuel mixing and combustion. It also enabled researchers to measure air motion and fuel spray injection characteristics.
The main areas of interest to the Loughborough team were the injection characteristics (the timing and duration of injection fuel), the variable valve timing (used to measure the impact of early intake valve closing on emissions and fuel consumption), and the ability to turn one of the engine's two inlet valves off at low load.
Comparisons between the fired optical and thermodynamic engine were possible at low loads where a given set of valve profiles, injection timings and ignition timings, produced the same engine load. The two engines were the same, so engine data from the two could be correlated with confidence.
Dr Wigley explained why Loughborough's optical engine was so important to the success of the project.
He said: "In the past, if you wanted to test an engine's performance you would use different speeds and loads, and you'd rely on the instruments to give you data about fuel economy and CO2 emissions. You could plot trends if performance improved, and carry on with the research. However if the data indicated performance was getting worse, you'd have to back off. At Loughborough, using the key laser technology, we could continue to run the conditions and crucially, see why it was worse."
Lotus first began working with Loughborough University back in 1997. The Group Lotus Senior Research Fellowship, which is held by Dr Wigley, was later created in 2001.
Lotus had been looking for a partner to help develop their automobile technologies, with the proviso that the partner had some knowledge of the industry, fuel spray technology, optical engines and the optical diagnostics to go with them. Lotus realised that the places with both the kit, and the expertise, were to be found at universities.
Dr Wigley said: "Our links with national and international universities, and with key players in the automobile sector are long, trusted and vital. We are happy to share our research and are willing to talk to industry and understand their needs."
"When academics and industry work together they can produce ground-breaking results to address the urgent and very real issues facing global manufacturers. The technology behind Project HOTFIRE will easily find itself in the engines of the future, and will benefit both the car buyer and the environment too."
As a direct result of Project HOTFIRE, a combustion concept engine has been developed by Lotus Engineering and Continental Powertrain and installed in a low CO2 technology Opel Astra demonstrator vehicle. The car and engine have attracted interest from a number of large manufacturers.
Project HOTFIRE has gone on to win prestigious awards, such as the 2008 Engineer Technology and Innovation Awards, for its ability to cut fuel consumption by 15 per cent, without sacrificing power. The national awards were set up to recognise the best examples of collaborative work undertaken by the UK's most innovative companies and its world-class universities.
Two PhD students from Loughborough gained exceptional experience during Project HOTFIRE, developing skills in optical diagnostics, engine cycle modelling, combustion system design and advanced experimental apparatus design and operation.
And the project has stimulated a new research project with the same partners to investigate high-load, downsized boosted engines for low fuel consumption and emissions.
But despite the positive results, the global interest, the awards and the training opportunities surrounding Project HOTFIRE, Dr Wigley knows the current economic climate will have an impact on the automobile industry and research.
He said: "There is still a long way to go in the areas of fuel economy and emissions. With HOTFIRE we looked specifically at 'part load' or low revs at 2000-3000 rpm. We are now seeking funding to continue this research, looking at engines at 'high load'.
"The recent, dramatic downturn in the industry certainly limits research opportunities. However both the EU and American governments have strict timetables and demands on environment and emissions, which ensures projects such as HOTFIRE will always be of interest, and needed."
