Imperial celebrates its automotive research prowess

Car engine

Colin Smith takes a guided tour with academics to discover how their research is helping to shape how cars will be made in the near future.

The Department of Mechanical Engineering at Imperial has been at the forefront of research to develop the next generation of vehicles for more than 40 years. Colin Smith takes a guided tour with academics to discover how their research is helping to shape how cars will be made in the near future.

Researchers in the Department are carrying out research to improve combustion engines, advance hybrid motors and progress the way that cars are put together in an effort to make the next generation of vehicles safer, more economical and more sustainable.

Professors Taylor and Hardalupas are also collaborating with Honda on ways to reconfigure combustion engines

For 30 years, Professors Yannis Hardalupas and Alex Taylor have been working behind the scenes on projects to improve the performance of combustion engine vehicles.  They feel that ongoing refinements to the engine will enable it to maintain its dominance for many years to come.

Currently, their research involves investigating the effectiveness of new types of fuels such as bio ethanol and synthetic alternatives for use in combustion engines.

They are also looking at ways of modifying the diesel engine so that it can run on regular gasoline. Diesel engines are very fuel efficient but have high emissions, whereas gasoline engines are less fuel efficient, but have lower emissions.  The researchers say making a diesel engine run on gasoline could improve their fuel efficiency and reduce harmful particulate emissions to zero.

Particulates from car exhausts currently cause smog that leads to approximately 250,000 preventable deaths in the UK each year.

Professor Taylor said: “Since the 1970’s a lot of research has been devoted to improving the way that combustion engines perform to reduce their impact on the environment. We believe that we can still make them even cleaner and more efficient, which means that these engines could stay around for a lot longer than many people previously predicted.”

Turbo charged

Another way to make combustion engine vehicles even more efficient, say researchers is to add a turbo charger.

“Turbo chargers aren’t just for petrol heads,” said Ricardo Martinez-Botas, Professor of Turbomachinery. “They provide a solution that can make the family car more sustainable.”

Turbo chargers work by sucking more air into the engine, which increases its power. It enables manufacturers to downsize an engine without compromising on their power or performance.

Professor Martinez-Botas has patented a system that uses exhaust gases to propel a high-performance turbine that is coupled to a high-speed electrical generator that makes use of energy that would otherwise go to waste.

This technology would reduce the number of engine cylinders from six to four, while still enabling the engine to maintain its power as if it was a six cylinder. Professor Martinez-Botas says the technology could cut fuel consumption by up to 35 percent.

Hybrid future

Other methods for improving fuel efficiency involve completely reconfiguring how car engines work.

Already becoming more prevalent on the road, hybrid cars combine a conventional combustion engine, which is more efficient over long distances, and batteries that power electric motors, which are more efficient in city environments where cars are stopping and starting. Some engineers in the Department predict that these hybrid vehicles may become one of the dominant modes of transport in the future.

Dr Greg Offer, EPSRC Career Acceleration Fellow in the Department, said: “Hybrid cars could be the type of technology that completely transforms how we drive. However, more work needs to be done to understand how batteries function to improve the performance of these vehicles.”

Dr Offer is studying the electrochemistry of batteries to improve their effectiveness and longevity.  In particular, he has developed a device that enables the physical conditions of the road to be simulated to test how batteries perform.

New industrial processes

Imperial researchers are not just carrying out work under the bonnet to make cars more efficient. They are also looking at ways to make the bodywork, which includes the chassis and frame, lighter. This means that cars would reduce petrol consumption.

Jianguo Lin, Professor of Mechanics in the Materials Division, is working with industry to improve the processes for making chassis and frame components lighter, without compromising on qualities such as their strength.

Currently, the frame and chassis is made from steel, which ensures that passengers are protected from impacts should they be unlucky enough to be in an accident. However, these steel frames are heavy and reduce fuel efficiency.

Professor Jianguo Lin has devised a method that will enable manufacturers to do away with some of the heavier steel frame components and instead use lighter aluminium ones that are just as robust.

“Our method combines two processes in one where the aluminium alloy is heated and stamped into a shape to make a part. Heating the alloy makes it more malleable, which means that it can be formed into shapes that are much stronger,” said Professor Lin.

Making the car frame lighter, Professor Lin says, could reduce fuel consumption in a standard vehicle by up to 23%.

Professor Lin has established a start-up company through Imperial Innovations, where to he aims to license this technology to automotive manufacturers around the world.

Formula One

There are other ways of making the family car lighter and academics are also working with car makers to apply manufacturing techniques used in Formula One.

Of particular interest to researchers are composite materials. These consist of plastics reinforced with carbon fibre. They are used to make parts of the bodywork in racing cars because they are strong and durable, yet light-weight. However, it is currently expensive to produce.

Dr Ambrose Taylor, who is a Reader in Materials Engineering, is investigating new processes for manufacturing composite material so that it is more cost effective to produce. In particular, Dr Taylor is working on projects to increase the toughness and lower the cost of producing this material via improved manufacturing processes and through the use of nano-materials.

Dr Taylor said: “The humble family estate car could in the future have the roof or the car bonnet made from the same material that is used to build Formula One cars.  Composite materials could help to make car bodywork lighter, while maintaining its strength and durability.”

Bonding research

Gluing more car parts together, instead of welding, could also lessen the load say researchers. These glues or adhesives are currently being used by manufacturers such as Aston Martin and Lotus. They can reduce the overall weight of a car and improve fuel efficiency. They can also absorb energy, making the parts they bond together more shock resistant.

Working with adhesive manufacturers such as the German company Henkel, Dr Taylor is also carrying out evaluations of adhesives to determine their durability and make improvements to their formula so that they can be produced at lower costs and last longer.

Reducing friction

The researchers in the Department are not only looking at better ways of gluing parts together, they are also looking at ways to ensure that moving parts slip easily past one another to reduce friction and wear in cars.

Academics who work in tribology, which is the science of friction and wear, are working with the engineering company SKF on ways to reduce friction and increase the reliability of wheel bearings. They are also working with the company Valvoline to design low friction oils for gears in cars and with the energy and petrochemical company Shell to develop lubricants that improve the efficiency of engines.

Professor Hugh Spikes, who heads the tribology group at the College, said: “A large proportion of the energy from fuel used in cars is ultimately wasted in the engine, the transmission, the tyres and even the windscreen wipers due to friction. Reducing friction is an important way to reduce fuel consumption of cars to make them more sustainable.”

The next generation

Future improvements to how cars perform will rely on the next generation of engineers being fully prepared for what industry requires, say researchers. That is why the Department is working on a range of student initiatives such as Imperial Racing Green (IRG).

Professor Peter Cawley, Head of the Department of Mechanical Engineering, concluded:

“It is not enough to be world leaders in automotive research. We also need to be able to enthuse and prepare the next generation of engineers about the challenges and opportunities that lie ahead. That is why project such as IRG are so important. Thanks to the support of our academics, students get the opportunity to design, build and race their own low emission racing cars. This provides them with some of the valuable skills needed in their careers and prepares them for an industry that is moving towards a very low emission future. “