Supercar

In the future, EPSRC research could lead to an altogether better automobile, writes Geoffrey Moore.

History is more or less bunk,” said Henry Ford, the famous mass producer of black cars, in 1916. But the long history of car technology development perhaps proves him wrong. 

Back in 1771,  the French engineer Nicolas-Joseph Cugnot took to the road in his steam-powered vehicle, considered by many to be the first automobile. Since then around 100,000 patents have led to the creation of modern cars. For example one of the earliest internal combustion engines, designed to run on turpentine, was patented by Stuart Perry in 1844.

Today’s cutting edge research is still pushing back the boundaries of that concept over 160 years later.

This century’s pressures of protecting the environment and human health occupy the mind of an engineer working on diesel power at the University of Brighton, Professor Morgan Heikal. “My big challenge is that future European legislation for diesel vehicle emissions is very tough. If current trends continue it is likely that in about ten years emissions of nitrous oxide (NOx) from new vehicles will have to be around one-fiftieth of today’s levels. Existing technology can achieve big reductions in NOx but fuel consumption rises. We have to hit both.”

Professor Heikal’s EPSRC-funded research is focused on killing emissions at source rather than cleaning up after combustion. Surprisingly, cooler combustion may be one answer since NOx is formed at high temperatures. Other methods are high gas exhaust recirculation and lower compression ratios. “I think we will need engines which are so well managed by electronics that they can switch to operating conditions which best achieve low emissions. I am confident our advanced laser diagnostic testing and modelling techniques will help us establish optimum cylinder combustion.”

According to Professor Heikal diesel technology has a rosy future: “About 45% of new cars sold in Europe are diesel powered and I see this moving on to a generation of diesel/electric hybrids. As engine researchers often say, we will still be working on reduced emissions when they are less than from a cow in a field.”

We have ignition

At Brunel University, Professor Hua Zhao’s EPSRC-supported research is fuelled by petrol.

“The image of diesel power – noisy and slow – still prevails in the USA, and Japan does not use diesel, so petrol power has a big future. We are developing a new engine with leapfrog improvements in performance, fuel economy and exhaust emissions.”

The dramatic exhaust pollution reduction that will be needed in future has inspired some cutting edge research.

“Until recently, improvement was a trade-off between reducing emissions or fuel consumption,” explains Professor Zhao, “our breakthrough is to reduce both at once using a new combustion process called Controlled Auto Ignition (CAI). It beats conventional ignition by combining the mixture preparation of spark ignition with diesel auto ignition. We built the first multi-cylinder petrol engine running without spark plugs, by just changing the design of the camshaft.”

Professor Zhao believes that the full benefits of CAI – lower fuel costs and cleaner air – are probably ten years away. But he also has a gleam in his eye when describing a pneumatic hybrid engine using compressed air for braking and acceleration which would result in “huge fuel savings.”

A model of the Model T Ford

According to some pundits, hydrogen fuel cells could be the dominant vehicle power source in 25 years.

Dr Nigel Schofield of the University of Manchester is contributing to the early stages of this potential step change in automotive history by focusing on their practical application in vehicle drive trains. The London black cab is the chosen test bed for his project.

“An EPSRC grant is helping us develop an alternative all-electronic drive system,” he says, “high-powered batteries give the peak power of 80kW needed for good acceleration. But a 6kW fuel cell will deliver a high percentage of the basic energy needed for typical city and suburban journeys, greatly extending vehicle range between refuelling.”

According to Dr Schofield the big potential pay-off for busy cities like London is zero emissions from vehicles: “Once the concept has been road tested I hope that our four industrial partners will take it on to production, with cleaner cabs on city roads in about five years. I also foresee this research realising new vehicle component concepts that could open up a big opportunity for the UK automotive component industry.”

Cleaner power will only please motorists if can be combined with improvements in reliability. Dr Julian Booker at the University of Bristol could be their hero if his EPSRC-supported project on component fatigue design pays off.

“After 100 years of effort on fatigue failure we are still making basic mistakes like stress concentrations in vehicles which sometimes cause catastrophic breakdowns. Such failures may cost billions each year,” he explains.

The initial research uses 125 fatigue failure case studies mainly from the automotive and aerospace sectors to focus on where improvement is most likely to be achieved.

“The concept design phase is where we see most scope,” Dr Brooker comments, “the aim is for design that is as near faultless as possible, with high confidence, so that time and costs can be reduced in later development stages. We aim to equip the designer with the non-analytical tools to rapidly compare concept designs for fatigue risks or to aid detailing. The potential cost benefit will come from reduced intermediate prototyping before production and fewer failures in service – there should be particular benefit for less experienced design engineers.”

Dr Booker does not yet foresee the demise of breakdown services but maybe they should start to worry. 

Design for reliability

Buffeting rather than breakdowns are what concern aerodynamicist Dr David Sims-Williams at the University of Durham. “Aerodynamic unsteadiness can lead to handling problems at high speed,” he tells us, “as carmakers move to lighter weight to improve fuel consumption this will become more significant.

One well-known sports car suffered a series of accidents which were traced back to such an aerodynamic issue.

” Today’s aerodynamicists have to develop a vehicle’s aerodynamics without dramatic changes to car style. For example, altering the underside of the car or the angle of the rear windscreen can deliver big gains.

“Research funded by EPSRC geared towards the racing car industry is heading for a breakthrough – a novel magnetic levitation system for wind tunnel testing of racing cars is being used to avoid the interference of rigid supports used conventionally. We are on track for 40% size scale models using levitation which would be a first.”

Looking ahead, Dr Sims-Williams speculates that “one day car aerodynamics could come ahead of fashion.”

No doubt Henry Ford himself would have approved.  

This article has been reproduced from the EPSRC web site by permission.