Engineering and the Environment New Boundaries

Engineering and the Environment New Boundaries

Low cost engineering design Industry reduce design costs using University software Manipulating sound Improving home entertainment user experience Tackling hearing loss Influencing policy in the NHS Groundbreaking bioengineering Improving knee replacements to benefit patients

2014

In this issue Welcome to Engineering and the Environment New Boundaries.

In this issue, you will discover how our research is addressing some of the most challenging issues facing society, from improving aerospace transport efficiency to developing innovative solutions for medical conditions.

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Engineering and the Environment at Southampton brings together a wide range of engineering disciplines, including acoustical, aerospace, biomedical, civil, computational, electro-mechanical, environmental, geotechnical and materials engineering, energy technologies, ship science and transportation.

On page four, find out how engineers at Southampton have produced software that has been used by industry to reduce the cost of designing such large structures as aircraft, leading to a spin-out company. On page 10, you can read how researchers at our worldleading Institute of Sound and Vibration Research are improving our understanding of the cochlea in order to develop better hearing screening tests.

By manipulating sound waves, our researchers are able to provide surround sound systems using small loudspeaker arrays located in front of a TV, and to cancel out the sound in aircraft cabins (now both in commercial production). Find out more on page 12.

And continuing the bioengineering theme that we started on page 10, we move from the ear to the knee. On page 16, read how our researchers are working with orthopaedic manufacturers to improve knee and hip replacement technologies in order to reduce failure rates and increase patient outcomes.

For more information, visit our website www.southampton.ac.uk/engineering

Please send us your feedback We are keen to receive any feedback you have about Engineering and the Environment New Boundaries.

If you have any comments or suggestions, please send them to engenv@southampton.ac.uk

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1 Low cost engineering design

Industry reduce design costs using University software Page 4 2 Tackling hearing loss Influencing policy in the NHS. Page 10 3 Manipulating sound Improving home entertainment user experience.

Page 12 4 Groundbreaking bioengineering Improving knee replacements to benefit patients.

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More highlights Reducing aircraft noise Tools to tackling noise pollution.

Page 18 Mapping below-ground services Reducing costly repairs.

Page 20 Recent publications Journal papers highlighting engineering impact.

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Low cost engineering design In an extremely aggressive civil and military aviation market, companies constantly need to improve materials, structures, aerodynamics and thermodynamics to remain competitive. Research carried out at Southampton enables major aerospace companies such as Boeing and Rolls-Royce to produce more fuel efficient, longer lasting engines at reduced cost.

“At the heart of a company’s critical advantage is its ability to explore very complex new designs quickly while managing product risk. Our research can help companies manage this risk.”

Andy Keane, Professor of Computational Engineering

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Our engineers advise aerospace companies on how to optimise engine component design

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“Our tools allow engineers to optimise engine components by fractions of per cents.

A 0.1 per cent energy saving on the fuel burn of a large engine is considered a major breakthrough these days as all the obvious design changes that afford large efficiency gains have already been achieved.”

Andy Keane, Professor of Computational Engineering

Critical advantage “At the heart of a company’s critical advantage is its ability to explore very complex new designs quickly while managing product risk,” says Andy Keane, Professor of Computational Engineering and Director of the Rolls-Royce University Technology Centre (UTC) for Computational Engineering. “Our research can help companies manage this risk,” he adds.

The UTC for Computational Engineering represents a formal agreement with RollsRoyce for certain resources and funding for specific business-critical projects, as well as primary research. Research led by Andy and Jim Scanlan, Professor of Design at the University, has created a range of new tools to support design teams working on complex aerospace products.

“Through our design software tools, we have spent a lot of time helping aerospace companies develop balanced designs. In the past, performance has been the focus with designs, but this can result in unnecessarily expensive products. Our analysis codes help balance cost and performance,” says Jim. Aiding critical decisions “The work we have done for Roll-Royce is divided into four sections: design optimisation software; uncertainty control, modification and modelling software; geometry manipulation; and costing and lifecycle analysis through wear and tear,” says Andy. “Under these four headings, we produce tools to support analysis and decision making as well as supporting engineers so that they can make informed decisions. Designing a new engine is essentially hundreds of small decisions based on all the parts of the engine – we try and support each decision with evidence or experimental results.”

The Design Analysis Tool for Unit cost Modelling (DATUM) project was not only supported by Rolls-Royce, but also through grants from the Engineering and Physical Sciences Research Council (EPSRC) and the European Union, totalling over £2m.

“Our design optimisation software can be used with the commercially available computer-aided design (CAD) tools that

aerospace companies such as Rolls-Royce, Airbus and BAE Systems use to design their products,” says Andy. “The engineers in the companies use the CAD packages as electronic drawing boards, but our software enables them to use CAD as a graphical programming environment where they can make vital decisions on the components. It then generates numerical code that is fed into machining tools that cut the components.”

Optimising components Andy explains that one of the main factors that govern fuel consumption in a jet engine is leakage of flow around the edges of the blades spinning inside the turbine.

The stiffer engineers make the casings and mountings of the turbines, the closer they can control leakage. “But this makes the engine heavier and more expensive, so the engineer has to make a trade-off decision between a more fuel-efficient engine versus a lighter engine,” he says.

“Our tools allow engineers to optimise engine components by fractions of per cents.

A 0.1 per cent energy saving on the fuel burn of a large engine is considered a major breakthrough these days as all the obvious design changes that afford large efficiency gains have already been achieved,” Andy says. “The research we do is rather like the work in the F1 industry, where teams try to make their cars go faster by hundredths of a second; we are trying to achieve hundredths of a per cent gains in fuel efficiency.”

The team has also produced tools that combine data from factory inspection processes with geometry manipulation schemes that come from the field of cinema film animation. This allows designers to model uncertainty in turbine blade shape and its consequences on blade life operation.

The use of highly structured cost and manufacturing knowledge tools has dramatically improved capabilities in the aerospace companies. Andy and Jim’s DATUM project has provided Rolls-Royce’s integrated project teams with unit cost information to enable them to make tradeoff decisions and to allow for the effects of uncertainty to be captured and understood in an industrial setting. “Rolls-Royce can u

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“Building unmanned aerial vehicles (UAVs) enables us to go through the design lifecycle, which helps us to think about how we might develop future design software tools.”

Jim Scanlan, Professor of Design and founder of Plexus Planning Ltd

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now routinely undertake a very detailed cost analysis of an entire three-shaft engine in less than a couple of days at the concept design stage. Prior to DATUM it would have taken Rolls-Royce weeks,” says Jim. Spin-out success The tools that the team has developed are now in daily use, not only with RollsRoyce, but also BAE Systems, Airbus and related companies. Further development of design efficiency software resulted in the launch of Plexus Planning Ltd, founded by Jim in 2003. The spin-out company now has a turnover of £500,000 with annual growth of over 20 per cent. “At Plexus we have developed a software toolkit that enables massively complex problems to be simplified. This enables the representation of a wide range of management

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problems, from project planning to supply chain management,” says Jim. Plexus has now established a strong reputation within the aerospace industry, with customers including Airbus, Boeing, Bombardier and the UK Ministry of Defence.

And in 2011, the US Navy bought Plexus licences to model all concept design work.

3D printed planes Andy and Jim have also brought together their ideas in rapid design and advanced manufacture by designing the world’s first three-dimensional printed aircraft. “We went from initial idea through the full design cycle to flight trials in four weeks and built an aircraft that contains no conventional fasteners or fixings such as nuts, bolts and screws,” says Andy.

Our printed aircraft demonstrates what advanced approaches to design can achieve

The aircraft was printed in four large pieces, complete with all hinged control surfaces preassembled. And then the parts were simply snapped together to make the complete airframe. All the on-board avionics, control systems, power plant and batteries simply snapped into clip fittings, pre-designed into the airframe. The resulting aircraft met all the specifications on its first flight and is capable of speeds of over 90mph.

“The printed aircraft demonstrates what advanced approaches to design can achieve,” says Jim. “Building unmanned aerial vehicles (UAVs) enables us to go through the design lifecycle, which helps us to think about how we might develop future design software tools for aerospace companies. It also provides us with an excellent platform to teach our students about design,” adds Andy.

The University’s expertise in UAVs has led to the formation of two other spin-out companies from the University. Solair Aviation Ltd, in collaboration with a local company and local investors, uses the sophisticated computational engineering modelling developed by their team. The company is developing a new piloted micro light aircraft and it is estimated that there will be a market of over 100 aircraft per year with an eventual turnover of over £6m.

Public awareness “The other spin out SkyCircuits, develops the autopilot system for UAVs and has a large number of customers. We have sold over £100k worth of autopilot systems to these customers, which include the MET Office and several leading airborne surveying companies, including QuestUAV and Callen

Lenz,” says Jim, who is SkyCircuits’ Director.

Aspects of the research have attracted strong public interest, leading to widespread international publicity. This is true in particular of the team’s work on the first 3D printed plane. Publications and programmes that reported this development in detail included BBC online; New Scientist; Blue Peter; Irish Times; MSN India; and the Los Angeles Times. These articles, all written for non-specialist audiences, enhanced understanding of the new technology and its practical significance among the wider public.

For more information on this research, visit www.southampton.ac.uk/engineering/ supporttools

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Tackling hearing loss Hearing impairment is the most frequent sensory deficit in human populations, affecting more than 250 million people worldwide. Auditory specialist Dr Ben Lineton explains how research at the University has helped detect deafness in babies and how his work is improving hearing tests.

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Why is it important to diagnose deafness early?

Deafness affects over one in 1,000 babies.

If a child is diagnosed at birth, he or she can benefit from earlier educational support, hearing aids or cochlear implants to help improve language, educational and emotional development. Before 2001 the standard test for permanent childhood hearing impairment (PCHI) in the UK was the health visitor distraction test, based on the observation of a seven-month-old baby’s reaction to a distracting sound.

Because PCHI was diagnosed relatively late, children and their parents were not receiving the best support available.

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How has the University contributed to diagnosing deafness?

In the 1990s my colleagues in the University’s Institute of Sound and Vibration Research (ISVR) and the Faculty of Medicine

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tested a new screening procedure to investigate its use in the UK. It was subsequently adopted by the NHS as a universal test for all newborn babies.

The test, originally developed at University College London, was based on the fact that healthy ears emit low-level sounds called otoacoustic emissions (OAEs), which can be detected by a microphone in the ear canal, usually within a few days of birth.

One of my colleagues, Professor Mark Lutman, was also influential in producing a European consensus statement on the benefits of universal newborn hearing screening using OAEs. (For more information, see page 20.)

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What is the impact of this research on society?

The NHS in England introduced an innovative test using transient evoked OAEs (TEOAEs), a type of OAE that occurs when

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the patient hears a certain sound stimulus.

More than six million newborns have now been screened, leading to around 10,000 cases of PCHI being detected. This has enabled health services to detect PCHI earlier in babies and provide the support to help them fulfil their potential.

As a result of our work, the World Health Organization has recommended that countries with the appropriate rehabilitation services should adopt universal newborn screening tests. Our research has also informed policies in other countries, including the USA and Australia.

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How does your research fit in with the newborn screening tests?

My research involves trying to understand more about what happens in the cochlea when OAEs are generated, so that the relationship between the test measurements and hearing impairments

can be understood. The hope is that hearing tests can then be improved.

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What does your research involve?

be used to monitor hearing damage that may occur when people take medication – for example some antibiotics can affect a person’s hearing.

Cells in the cochlea contain motor proteins – proteins that detect motion and produce TEOAEs. The way that the thousands of cells vibrate and interact to generate OAEs is not well understood. One of my research areas is trying to model the generation mechanisms of OAEs from first principles so that we can understand the link between cochlea physiology and the properties of OAE signals.

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I am also looking at ways of improving the techniques for measuring and interpreting OAEs. OAEs are generated at very low levels and these can be buried in a lot of noise so they are difficult to identify. We are looking to improve the test by removing more of this noise interference. We are also investigating whether our improved hearing tests can

The fantastic facilities and acoustic, signal processing and audiology experts that are all in ISVR means that Southampton is the right place to carry out my research. There are so many groups working on so many aspects of sound and vibration research that we are able to look at a challenge in lots of different ways and come up with innovative solutions.

Why did you become interested in this research topic?

With a background in acoustics and fluid mechanics, I was drawn to this intriguing area of audiology. I find it gratifying that my research will help change people’s lives.

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Why is Southampton a good place to do your research?

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Is multidisciplinary collaboration important?

Cross-collaboration with researchers in different areas of the University is also an important part of my work and is built into the ethos of the institution. The ISVR has a history of collaboration with colleagues in the Faculty of Medicine. For example, one other project is looking at inflammation in the ear in older patients and whether this has an influence on hearing loss as you age.

For more information on deafness screening tests, visit www.southampton.ac.uk/engineering/ newborn_hearing_screening

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“Full ‘cinema surround-sound’ has been developed without the need for multiple speakers – a particularly attractive feature for space restricted households.”

Philip Nelson, Professor of Acoustics

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Sound manipulation Reproducing sound accurately is big business in the entertainment industry, whereas reducing sound pollution is equally important for aerospace companies.

Research at Southampton is helping both industries manipulate sound to benefit consumers.

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Our researchers have developed full cinema surround sound without the need for multiple speakers around the room

Philip Nelson, Professor of Acoustics at the Institute of Sound and Vibration Research (ISVR) at the University, explains that the characteristics of a sound source can be deduced by measuring the sound field that it radiates, which is known as an inverse problem. “A sophisticated understanding of these inverse problems has led to the development of mass-produced systems for living room 3D sound,” he says.

Sound accuracy

“Over 1,000 Dash-8 Q400 aircraft are fitted as standard with an active control system that uses 42 shakers, which vibrate in order to cancel out the vibrations from the propellers.”

Steve Elliott, Professor of Adaptive Systems

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Philip, Dr Takashi Takeuchi, Dr Filippo Fazi and colleagues at ISVR have been investigating ways to improve the accuracy with which sound can be reproduced; a recorded sound signal input to a loudspeaker is not completely replicated in the sound field produced by the speaker, because not all frequencies of sound are radiated equally.

“This led us to design digital filters that can process the signal before it is input to the loudspeaker to ensure that it replicates it as closely as possible at some point in the sound field radiated,” explains Philip.

“We then expanded our research to look at transmitting sound from a number of loudspeakers and this enabled the desired acoustic signals to be reproduced at multiple points in space, ensuring the accurate reproduction of a recorded sound field at the ears of one or more listeners,” he adds.

The significance of the team’s work has been recognized by world-leading sound system manufacturers such as Samsung, Yamaha

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and Marantz, as well as Kajima Corporation, Japan’s largest construction company, which has a turnover of $15bn.

Surround sound “Kajima was primarily interested in simulating the acoustical environments offered by the buildings that they designed – a process known as ‘auralisation’,” says Philip. “This involves presenting to the ears of the listener a replica of the signals that would be heard in a concert hall, office or meeting room that was being designed,” he adds.

Takashi’s involvement in the project led to the collaboration between Kajima and the team at ISVR. The team found that a compact array of loudspeakers directly in front of the listener could be adapted to transmit signals to the ears so that the listener would think they had come from five loudspeakers around the room. “Full ‘cinema surround-sound’ was developed without the need for multiple speakers – a particularly attractive feature for space restricted households,” says Philip.

The technology has since been licensed to some leading audio brands with product sales already reaching over $7m.

Working with the Electronic and Telecommunications Research Institute (ETRI) in Korea, and Filippo in ISVR, Philip has taken the research one step further.

“We have built a system of 40 loudspeakers in a large spherical array that produces the ultimate sound reproduction system. The large volume sphere allows you to replicate

the exact sound field in space and time under anechoic conditions,” says Philip.

between the two sounds – the result is you have a quieter overall sound field,” says Steve.

“Our most recent project in this area is a £6m grant from the Engineering and Physical Sciences Research Council (EPSRC), to work with the universities of Salford and Surrey, and the BBC, to investigate practical technologies for generating 3D sound reproduction systems in the next-generation of living rooms where there isn’t space for 40 speakers in a sphere arrangement.”

Working closely with industrial sponsors Ultra Electronics, Steve and his team have developed structural actuators that can be built into the fuselage of planes, allowing both the vibration inside the passenger cabin and the noise level to be controlled.

“The application that has been the most commercially successful to date has been controlling the sound on propeller aircraft,” says Steve. “Over 1,000 Dash-8 Q400 aircraft are fitted as standard with an active control system that uses 42 shakers, which vibrate in order to cancel out the vibrations from the propellers.”

Cancelling out sound Research at Southampton not only focuses on replicating sound, but looks at how noise can be reduced using different sounds. This is the principle that the addition of a secondary artificial noise or vibration source can be used to cancel out the effect of the primary disturbance.

Control of problematic noise and vibration has traditionally been tackled using passive measures such as sound-absorbing tiles, heavy partitions and damping materials.

These can be effective, but performance is limited where the vibration or noise source is relatively low frequency, or where lightweight material solutions are required.

Steve Elliott, Professor of Adaptive Systems at ISVR, first worked with Phil to investigate how loudspeakers can be used to generate a sound field that has got the same wave field and amplitude as the sound field that you want to control, but which is exactly out of phase. “You then get destructive interference

Consumer benefits Steve explains that in the aeroplane cabin, the passenger experience is better. “The noise levels are reduced to a similar level as you would get from a jet engine,” he says.

The cost of including an active control device on the fuselage is relatively low compared to the overall cost of the aircraft.

But Steve explains that there is also the potential to use active control devices in cars. “The cars that could benefit from active control are the lightweight, massproduction cars that are incredibly price sensitive, because all the sound-proofing materials have been removed,” he says.

Thanks to Steve and his team, the cost of the active control system is much reduced. And many of the elements needed are already

installed in the car. “The loudspeakers and amplifiers for the in-car entertainment system are already there and can be used for the active control system,” explains Steve.

Manufacturers are also reducing the weight of cars to make them more fuel efficient, which can include changes in engine design.

As a result of these engine changes, some of the luxury car manufacturers are now using active control systems to disguise undesirable engine noise. “The result is that the motorist is unaware of the changes apart from an increase in fuel efficiency,” says Steve.

Another application for active noise systems focuses on generating a more traditional ‘engine’ sound for electric and hybrid vehicles. “A safety consideration for electric vehicle manufacturers is that pedestrians may not be warned of the car’s approach,” says Steve. “We have been involved in a group design project that has looked at generating a sound at the front of a vehicle so that pedestrians are warned, but that does not create noise at the back or side of the car. We have engineered a very directional source of sound that can be used as a warning device, but that allows the overall noise of the vehicle to stay the same,” he adds.

For more information on how research at Southampton manipulates sounds to improve consumer experience, visit www.southampton.ac.uk/ engineering/sourcesofsound

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Groundbreaking bioengineering Around 1.3 million knee replacements are carried out worldwide every year and this is set to increase dramatically over the next 10 years due to a rising and ageing population. Professor of Applied Biomaterials at the University, Martin Browne, describes how his research is helping improve knee replacements to benefit patients.

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Why is it important to develop better knee replacements?

Knee implants are continually evolving and patient demand is ever increasing; people are living longer and are more active in later life, placing increased demands on the implant.

Patient satisfaction with knee implants is relatively low compared to other implants such as hip replacements, because the knee joint is more unstable, and this can affect the confidence of the patient.

What manufacturers are aiming for is to produce an implant that recreates the natural movement of the joint. While at first sight the knee joint might appear to operate as a simple hinge, in reality, it must cope with a far more complicated range of motion and stresses.

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What does your research involve?

Bioengineering covers many areas, but in my case I am looking at the application of engineering mechanics and materials in the human body. In the Bioengineering Science Research Group, we have significant expertise in applying novel computational and experimental techniques for bioengineering applications.

Our computational work is particularly focused on finite element modelling to simulate time-related and adaptive biological processes. We generate models of human bones and joints from computed tomography data, and these allow us to predict the performance of different prosthesis designs in specific patients.

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Can you explain more about your research on knee replacements?

Over a period of 10 years my team and I have worked with a major orthopaedic implant manufacturer who was looking to develop a new knee replacement.

Our input into the programme was part of a University Technology Partnership (UTP), and aimed to create a modelling environment with which the company could predict the robustness of the implant against wear.

Wear testing is a very time-consuming and expensive process, so by using the developed model, they were able to eliminate poorer

performing designs sooner, and take years off the design process.

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What impact does your research have on society?

Our modelling environment means that patients get a longer lasting implant, capable of withstanding harsher loading regimes. In terms of healthcare providers, our research means that they have lower costs due to the lower proportion of operations that need to be repeated; a revision operation to correct a faulty knee replacement costs at least twice as much as the initial operation.

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What are the benefits of working with industry?

Working with industry allows us to see how industries operate and get involved in the development of large scale projects such as the new knee – an implant that is being rolled out worldwide as we speak.

As well as working with large orthopaedic organisations, we get to work with the smaller orthopaedic companies that can’t really compete on a global scale and need to innovate to survive.

Working with these small, innovative companies allows us to evaluate novel biomaterials and joint replacement designs. A lot of this research can feed into our teaching and underpin new areas of investigation. In the orthopaedic world, there are many small companies trying to survive and we are a resource that can be very useful to them.

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organisations all over Europe, and we are interacting with Indian institutes through the UKIERI initiative run by the British Council.

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What motivates you to do your research?

In common with a number of my colleagues, I have seen first-hand how debilitating conditions such as arthritis can be on bones and joints, and current practice does not always have a satisfactory outcome. We need to find innovative solutions – as tissue engineering progresses, we may be moving away from the inert man-made materials currently used, towards biological solutions. The option of using tissue engineered cartilage is not viable yet, but as we progress towards this, the idea of hybrid artificial and tissue based materials is something I believe will become more prominent.

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What would you say is your biggest achievement here at Southampton?

My biggest achievement while at Southampton has been being part of the team that developed the world’s first large bearing ceramic-on-ceramic hip implant, which was designed to recreate the natural movement of the hip while exhibiting very low wear – this implant was aimed at the younger patient and it is performing very well to date.

For more information on Martin’s research, visit www.southampton.ac.uk/engineering/ kneedesign

How important is multidisciplinary collaboration in your research?

Multidisciplinary collaboration is essential to our work. Without the input of clinicians for example, engineers may not appreciate the challenges that must be addressed. As a group, we work with a broad spectrum of researchers, including physiotherapists, computational modellers, surgeons, radiologists, biologists and chemists.

We don’t just collaborate with researchers within the University; we also work with companies in the European Union and worldwide. As a result of EU-funded projects we have built up relationships with

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In brief

Reducing aircraft noise

Reducing waste

In-car personal audio system

We are working with global aerospace companies to help them better understand and mitigate the causes of aircraft noise pollution. It is one thing to cancel out the noise in the cabin once it has been made (see page 12-15), but far better to make the source of noise quieter, which benefits householders living near airports.

Research carried out at Southampton has directly influenced UK waste management practice and behaviour of households, business and industry as well as government agencies.

A researcher from Southampton has developed a unique in-car personal audio system that aims to produce independent listening zones in the front and rear seats of a car cabin without the use of headphones.

According to the World Health Organization, aircraft noise pollution is an ‘underestimated threat’ to human health. Many airports set curfews or impose fines on aircraft that exceed noise limits, which can result in airlines incurring penalties of millions of pounds.

Rolls-Royce and Airbus work closely with our researchers through the Rolls-Royce University Technology Centre (UTC) and Airbus Noise Technology Centre (ANTC) respectively, to enable them to respond to this challenge.

The two centres have made a number of important breakthroughs, including an advanced landing gear prediction model used by Airbus and numerical techniques to predict sound-propagation in aero-engine ducts for Rolls-Royce.

Andrew Kempton, Chief Noise Specialist at Rolls-Royce, comments: “Research by the UTC at Southampton, with its breadth and depth of knowledge, independence of thought and aptitude for innovation, has helped to ensure the best technology is built into Rolls-Royce engines.”

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The modern waste industry is concerned with treating waste as a resource to be used efficiently, rather than simply a problem to be managed. And there is growing recognition of the need for environmental control of landfill in order to avoid passing a toxic legacy to future generations.

Ian Williams, Professor of Applied Environmental Science in the Waste Management Research Group at the University, and colleagues are at the forefront of implementing new ideas and technologies in order to reduce the amount of waste being sent to landfill.

The team carried out fundamental research on the circular economy for resources, waste prevention, reuse and recycling and how environmental legislation affects small- and medium-sized businesses. The research has generated multiple impacts, and includes an award winning study on the level of compliance with and impact and effectiveness of environmental legislation.

“Results from our research have been used extensively by industry and local authorities, UK government-funded Waste and Resources Action Programme guidance in 2012-13 and the development of Defra’s National Waste Management Programme for England in 2010-11,” says Ian.

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Different occupants of a car often want to listen to different audio programmes and at present these conflicting requirements can be solved by simply providing headphones. However, wearing headphones for prolonged periods of time may become tiring and is a safety issue for the driver.

Dr Jordan Cheer, from the University’s Institute of Sound and Vibration Research, has begun to develop an audio reproduction system that is capable of producing independent listening zones using the standard car audio loudspeakers, usually mounted in the doors of the car, and a set of small loudspeakers mounted to the headrests.

The small loudspeakers produce a directional sound field to help create the two independent listening zones, which is complemented by a signal processing strategy that optimises the audio signals used to drive each of the loudspeakers.

“The necessary degree of isolation between the two listening zones is dependent on the audio programme,” says Jordan. “If speech is being reproduced at the front seats and pop music is being reproduced at the rear seats, a higher level of isolation is required than if pop music were being produced in both zones.”

Solid foundations Researchers at Southampton are helping National Grid extend the working life of critical infrastructure by influencing the design and technical specification of high voltage electricity transmission support tower foundation systems.

The aim of power supplier National Grid is to distribute where possible more electricity through its existing network of electricity towers. This means the use of bigger conductors which in turn increase the physical loadings on towers that might not be designed for this.

When refurbishing an electricity line, National Grid checks each tower for defects and assesses the foundations, explains David Richards, Professor of Ground Engineering.

But because many existing towers are based on a 40-year-old design and a simplified uplift mechanism, concerns exist regarding foundation capacities.

identified additional soil/structure load transfer mechanisms that increase the uplift capacity of a tower’s foundation system,” says David.

“Our studies revealed that when a tower is subjected to impulse loading, the load on the foundations can effectively be doubled due to a suction-loading effect under the foundation base.” he adds.

“We carried out scaled physical modelling studies using a geotechnical centrifuge and extensive field tests where we simulated cable breakages on a series of towers and

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In brief Biogas from food Research at Southampton has pioneered the conversion of food waste into biogas, and now around 1.7 million tonnes of food waste is managed over 40 commercial biogas plants in the UK, allowing anaerobic digestion (AD) to be harnessed to produce renewable energy.

Organic wastes remain a major challenge because of their potential to generate greenhouse gases when landfilled. The UK produces approximately 16 million tonnes of domestic and commercial

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food waste a year. If this is used to create biogas, it could mitigate 34 million tonnes of equivalent CO2, including fuel replacement, offsets for fertiliser substitution and avoided landfill emissions.

In 10 years, biogas production from food waste has gone from pilot-scale studies developed by Professor Charles Banks and his team at the University, to being the UK government’s preferred option for this waste and a key topic for IEA Bioenergy which represents 28 countries worldwide.

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“Our continued research into AD has provided practical solutions that have improved digestion efficiency. This has major commercial significance as the throughput of existing plants can be doubled, with proportional increases in revenue from acceptance of waste material and sales of renewable energy,” says Charles.

Mapping below-ground services Researchers from Southampton are developing a device that detects buried service pipes or cables in different ground conditions in order to save time and money when repairs are needed.

Around four million holes are cut into the UK road network each year to install or repair buried service pipes and cables.

Significant proportions are exploratory holes which cause problems, including traffic congestion, pedestrian disruption and costs estimated at £7bn annually.

Dr Jen Muggleton, Dr Emiliano Rustighi and colleagues from the Institute of Sound and Vibration Research and Electronics and Computer Science, are involved in the internationally renowned Mapping the Underworld project to develop a multisensor location device that uses vibro-acoustics, ground-penetrating radar, low-frequency electromagnetics and passive magnetics to identify the locations of pipes and cables that need repair.

Cofferdam construction

Improved child hearing

Research and expertise at Southampton is informing policy on design and safety of temporary works structures, such as cofferdams, which are used in large-scale infrastructure projects.

Cochlear implants are the only successful treatment available for people with severe to profound hearing loss. Research into these implants at the Institute of Sound and Vibration Research has led directly to changes in health policy, including new guidelines by the National Institute for Health and Care Excellence (NICE).

Cofferdams are usually temporary circular enclosures built within a body of water to allow the enclosed area to be pumped out, creating a dry work environment. Professor of Ground Engineering, David Richards, and colleagues carried out extensive stability analysis of the 85m by 85m three-sided cellular cofferdam near St Germans, Norfolk, used to construct a new £38m pumping station.

The team carried out additional site investigations and soil testing on the clay that the cofferdam was embedded into and included tidal impact in their analysis of the structure. A site monitoring scheme was developed to validate these analyses with actual performance.

“The challenge was to construct the cofferdam while allowing the existing pumping station to stay operational. We also needed to make sure that the structure could withstand Jen has already developed a pipe location method that uses vibrations to detect pipework extreme tidal ranges.” says David. at a known location while also mapping the “The project further revealed the complexity ground surface. “We have found that the phase and range of temporary works design of the vibration at the ground surface is key to in the construction industry and has led locating the run of the pipe with the magnitude to a wider discussion around the need potentially identifying discontinuities,” she says. for an accredited formal qualification in A follow-on phase, Assessing the Underworld, has recently been funded that aims to remotely assess the condition of the services, and of the ground in which they are buried.

In the UK alone there are 10 million people with hearing loss and it is estimated that 200,000 of these may need a cochlear implant. However at present only 220,000 people worldwide have the benefit of an implant.

Cochlear implants can provide a striking improvement in quality of life for children with severe to profound hearing loss. But clinical examination, candidate selection and rehabilitation are much more difficult for children than adults.

Mark Lutman, Professor of Audiology at the University and his team, has developed the Categories of Auditory Performance (CAP) rating scale which can be used to predict the performance of paediatric cochlear implantation and rate outcomes from the treatment in everyday life.

“We have also carried out research to decide the best age at which to implant,” says Mark.

“We found that children given implants early are far more likely to go to mainstream schools than those given implants when they are already in an educational setting.”

temporary works design,” he adds.

For more information on these stories, visit www.southampton.ac.uk/engineering/ research/impact

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Selection of recent journal papers This sample of journal papers indicates the breadth of research in Engineering and the Environment at Southampton. For more research papers, please view individual staff profiles online.

Niu, X; Pereira, F; Edel, J B; de Mello, A J Droplet-interfaced microchip and capillary electrophoretic separations Analytical Chemistry, 2013, 130819124620005

Le Pen, L; Powrie, W; Zervos, A; Ahmed, S; Aingaran, S Dependence of shape on particle size for a crushed rock railway ballast Granular Matter, 2013, 15, 849-861

Knychala, J; Bouropoulos, N; Catt, C J; Katsamenis, O L; Please, C P; Sengers, B G Pore geometry regulates early-stage human bone marrow cell tissue formation and organisation Annals of Biomedical Engineering, 2013, 41, 917-930

Moore, D R; Rosen, S; Bamiou, D; Campbell, N G; Sirimanna, T Evolving concepts of developmental auditory processing disorder (APD): A British Society of Audiology APD Special Interest Group ‘white paper’ International Journal of Audiology, 2013, 52, 3-13

Bull, D J; Helfen, L; Sinclair, I; Spearing, S M; Baumbach, T A comparison of multi-scale 3D X-ray tomographic inspection techniques for assessing carbon fibre composite impact damage Composites Science and Technology, 2013, 75, 55-61

Koopmans, R-J; Shrimpton, J S; Roberts, G T; Musker, A J A one-dimensional multicomponent two-fluid model of a reacting packed bed including mass, momentum and energy interphase transfer International Journal of Multiphase Flow, 2013, 57, 10-28

Hamilton, A R; Thomsen, O T; Madaleno, L A O; Jensen, L R; Rauhe, J C M; Pyrz, R Evaluation of the anisotropic mechanical properties of reinforced polyurethane foams Composites Science and Technology, 2013, 87, 210-217

Cheung, J; Scanlan, J; Wong, J; Forrester, J; Eres, H; Collopy, P; Hollingsworth, P; Wiseall, S; Briceno, S Application of value-driven design to commercial aero-engine systems Journal of Aircraft, 2012, 49, 688-702

Cullington, H E Managing cochlear implant patients with suspected insulation damage Ear and Hearing, 2013, 34, 515-521 Box, S; Waterson, B An automated signalized junction controller that learns strategies by temporal difference reinforcement learning Engineering Applications of Artificial Intelligence, 2013, 26, 652-659 Stanton, N A; McIroy, R C; Harvey, C; Blainey, S; Hickford, A; Preston, J M; Ryan, B Following the cognitive work analysis train of thought: exploring the constraints of modal shift to rail transport Ergonomics, 2013, 56, 522-540 Robinson, A F; Dulieu-Barton, J M; Quinn, S; Burguete, R L The potential for assessing residual stress using thermoelastic stress analysis: A study of cold expanded holes Experimental Mechanics, 2013, 53, 299-317 Calles, O; Olsson, I C; Comoglio, C; Kemp, P S; Blunden, L S; Schmitz, M; Greenberg, L A Size-dependent mortality of migratory silver eels at a hydropower plant and implications for escapement to the sea Freshwater Biology, 2010, 55, 2167-2180

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Engineering and the Environment New Boundaries | University of Southampton

Woodman, N D; Siddiqui, A A; Powrie, W; Stringfellow, A; Beaven, R P; Richards, D J Quantifying the effect of settlement and gas on solute flow and transport through treated municipal solid waste Journal of Contaminant Hydrology, 2013, 153, 106-121 Weymouth, G D; Triantafyllou, M S Ultra-fast escape of a deformable jet-propelled body Journal of Fluid Mechanics, 2013, 721, 367-385 Busse, A; Sandham, N D; McHale, G; Newton, M I Change in drag, apparent slip and optimum air layer thickness for laminar flow over an idealised superhydrophobic surface Journal of Fluid Mechanics, 2013, 727, 488-508 Sharma, A S; McKeon, B J On coherent structure in wall turbulence Journal of Fluid Mechanics, 2013, 728, 196-238 Muggleton, J M; Yan, J Wavenumber prediction and measurement of axisymmetric waves in buried fluid-filled pipes: inclusion of shear coupling at a lubricated pipe/soil interface Journal of Sound and Vibration, 2013, 332, 1216-1230

Kingan, M J Open rotor broadband interaction noise Journal of Sound and Vibration, 2013, 332, 3956-3970 Holland, K R; Nelson, P A The application of inverse methods to spatiallydistributed acoustic sources Journal of Sound and Vibration, 2013, 332, 5727-5747 Di Monaco, F; Ghandchi Tehrani, M; Elliott, S J; Bonisoli, E; Tornincasa, S Energy harvesting using semi-active control Journal of Sound and Vibration, 2013, 332, 6033-6043 Lei, J; Glynne-Jones, P; Hill, M Acoustic streaming in the transducer plane in ultrasonic particle manipulation devices Lab on a Chip, 2013, 13, 2133-2143 Hallegatte, S; Green, C; Nicholls, R J; Corfee-Morlot, J Future flood losses in major coastal cities Nature Climate Change, 2013, 3, 802-806 Keyes, S D; Daly, K R; Gostling, N J; Jones, D L; Talboys, P; Pinzer, B; Boardman, R; Sinclair, I; Marchant, A; Roose, T High resolution synchrotron imaging of wheat root hairs growing in soil and image-based modelling of phosphate uptake New Phytologist, 2013, 198, 1023-1029 Zalitis, C M; Kramer, D; Kucernak, A R Electrocatalytic performance of fuel cell reactions at low catalyst loading and high mass transport Physical Chemistry Chemical Physics, 2013, 15, 4329-4340 Fangohr, H; Chernyshenko, D S; Franchin, M; Fischbacher, T; Meier, G Joule heating in nanowires Physical Review B, 2012, 85, 054437 Kaul, C M; Raman, V; Knudsen, E; Richardson, E S; Chen, J H Large eddy simulation of a lifted ethylene flame using a dynamic nonequilibrium model for sub-filter scalar variance and dissipation rate Proceedings of the Combustion Institute, 2013, 34, 1289-1297 Loveridge, F; Powrie, W Pile heat exchangers: thermal behaviour and interactions Proceedings of the Institution of Civil Engineers, Geotechnical Engineering, 2013, 166, 178-196

Clubley, S K Steel sections subject to a long-duration blast Proceedings of the Institution of Civil Engineers, Structures and Buildings, 2013, 166, 273-281 Blainey, S P; Preston, J M Extending geographically-weighted regression from points to flows: a railbased case study Proceedings of the Institution of Mechanical Engineers Part F: Journal of Rail and Rapid Transit, 2013, 227, 723-733 Leighton, T G; Chua, G H; White, P R; Tong, K F; Griffiths, H D; Daniels, D J Radar clutter suppression and target discrimination using twin inverted pulses Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2013, 469, 20130512 Leighton, T G; Turangan, C K; Jamaluddin, A R; Ball, G J; White, P R Prediction of far-field acoustic emissions from cavitation clouds during shock wave lithotripsy for development of a clinical device Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2013, 469, 20120538 Bailey, N J; Swinerd, G G; Lewis, H G; Crowther, R Global vulnerability to near-Earth object impact Risk Management, 2010, 12, 31-53 Liu, Y-Q; Kong, Y; Tay, J-H; Zhu, J Enhancement of start-up of pilot-scale granular SBR fed with real wastewater Separation and Purification Technology, 2013, 82, 190-196 Cook, R B; Bolland, B J R F; Wharton, J A; Tilley, S; Latham, J L; Wood, R J K Pseudotumour formation due to tribocorrosion at the taper interface of large diameter metal on polymer modular total hip replacements The Journal of Arthroplasty, 2013, 28, 1430-1436 Heaven, S; Salter, A M; Clarke, D; Pak, L N Algal wastewater treatment systems for seasonal climates: application of a simple modeling approach to generate local and regional design guidelines Water Research, 2012, 46, 2307-2323

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