̽��ֱ�� of Cambridge - aircraft

Strategic partner: Rolls-Royce

skbf2 — Mon, 16 Dec 2019 16:48:25 +0000

Researchers at Cambridge are working with Rolls-Royce to make aeroengines greener.

Green-sky thinking for propulsion and power

Anonymous — Wed, 04 Dec 2019 08:20:18 +0000

We’re seeing a transformational change in the propulsion and power sectors. Aviation and power generation have brought huge benefits – connecting people across the world and providing safe, reliable electricity to billions – but reducing their carbon emissions is now urgently needed.

Electrification is one way to decarbonise, certainly for small and medium-sized aircraft. In fact, more than 70 companies are planning a first flight of electric air vehicles by 2024. For large aircraft, no alternative to the jet engine currently exists, but radical new aircraft architectures, such as those developed by the Cambridge-MIT Silent Aircraft Initiative and the NASA N+3 project, show the possibility of reducing CO₂ emissions by around 70%.

A common thread in these technologies and those needed for renewable power is their reliance on efficient, reliable turbomachinery – a technology that has been central to our work for the past 50 years. Currently we’re working on applications that include the development of electric and hybrid-electric aircraft, the generation of power from the tides and low-grade heat, like solar energy, and hydrogen-based engines.

We’re also working on existing technologies as a way of reducing the carbon emissions, like wind turbines, and developing the next generation of jet engines such as Rolls-Royce’s UltraFan engine, which will enable CO₂ emission reductions of 25% by 2025. A great example is Dr Chez Hall’s research on a potential replacement for the 737. This futuristic aircraft architecture involves an electrical propulsion system being embedded in the aircraft fuselage, allowing up to 15% reduction in fuel burn.

A key element of meeting the decarbonisation challenge is to accelerate technology development. And so, over the past five years, our primary focus has been the process itself – we've been asking ‘can we develop technology faster and cheaper?’ ̽��ֱ��answer is yes – at least 10 times faster and 10 times cheaper. Our solution is to merge the digital and physical systems involved. In 2017, we undertook a pioneering trial of a new method of technology development. A team of academic researchers and industrial designers were embedded in the Whittle and given four technologies to develop.

̽��ֱ��results were astonishing. In 2005, a similar trial took the Whittle two years. In 2017, the agile testing methods took less than a week, demonstrating a hundred times faster technology development.

We describe it as ‘tightening the circle’ between design, manufacture and testing. Design times for new technologies have been reduced from around a month to one or two days using augmented and machine-learning-based design systems. These make use of in-house flow simulation software that is accelerated by graphics cards developed for the computer gaming industry.

Manufacturing times for new technologies have been cut from two or three months to two or three days by directly linking the design systems to rows of in-house 3D printing and rapid machining tools, rather than relying on external suppliers. Designers can now try out new concepts in physical form very soon after an idea is conceived.

Testing times have been reduced from around two months to a few days by undertaking a ‘value stream analysis’ of the experimental process. Each sequential operation was analysed, enabling us to remove over 95% of the tasks, producing a much leaner process of assembly and disassembly. Test results are automatically fed back to the augmented design system, allowing it to learn from both the digital and the physical data.

There’s a natural human timescale of about a week whereby if you go from idea to result then you have a virtuous circle between understanding and inspiration. We’ve found that when the technology development timescale approaches the human timescale – as it does in our leaner process – then innovation explodes.

̽��ֱ��New Whittle Laboratory will house the National Centre for Propulsion and Power, due to open in 2022 with funding from the Aerospace Technology Institute. A national asset, the Centre is designed to combine a scaled-up version of the agile test capability with state-of-the-art manufacturing capability to cover around 80% of the UK’s future aerodynamic technology needs.

Key to the success of the Whittle Laboratory has been its strong industrial partnerships – with Rolls-Royce, Mitsubishi Heavy Industries and Siemens for over 50 years, and with Dyson for around five years. So another component of the new development will be a ‘Propulsion and Power Challenge Space’. Here, teams from across the ̽��ֱ�� will co-locate with industry to develop the technologies necessary to decarbonise the propulsion and power sectors.

̽��ֱ��length and depth of these partnerships have so many benefits. They’ve enabled technology strategy to be shared at the highest level, and new projects to be kicked off quickly, without the need for contract lawyers. Joint industry–academic technology transfer teams move seamlessly between industry and academia, ensuring that technologies are successfully transferred into product.

Most importantly, the partnerships provide a source of ‘real’ high-impact research projects. It’s these long-term industrial partnerships that have made the Whittle the world’s most academically successful propulsion and power research laboratory.

We are at a pivotal moment, in terms of both Cambridge’s history of leading technology development in propulsion and power, and humanity’s need to decarbonise these sectors. Just 50 years ago, at the opening of the original Whittle Laboratory, research and industry faced the challenge of making mass air travel a reality. Now the New Whittle Laboratory will enable us to lead the way in making it green.

A bold response to the world’s greatest challenge
̽��ֱ�� ̽��ֱ�� of Cambridge is building on its existing research and launching an ambitious new environment and climate change initiative. Cambridge Zero is not just about developing greener technologies. It will harness the full power of the ̽��ֱ��’s research and policy expertise, developing solutions that work for our lives, our society and our biosphere.

Read more about our research linked with Sustainable Earth in the ̽��ֱ��'s research magazine; download a pdf; view on Issuu.

A rapid way of turning ideas into new technologies in the aviation and power industries has been developed at Cambridge’s Whittle Laboratory. Here, Professor Rob Miller, Director of the Whittle, describes how researchers plan to scale the process to cover around 80% of the UK’s future aerodynamic technology needs.

A key element of meeting the decarbonisation challenge is to accelerate technology development. And so, over the past five years, our primary focus has been the process itself – asking ‘can we develop technology faster and cheaper?’

Rob Miller

Whittle Lab

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

Yes

̽��ֱ��first non-stop transatlantic flight - 100 years on

sjr81 — Fri, 14 Jun 2019 11:37:00 +0000

Exhibiton and Vickers archive at Cambridge ̽��ֱ�� Library celebrates aviation milestone.

Britain from the Air: 1945-2009

sjr81 — Thu, 21 Feb 2019 17:25:21 +0000

Aerial photographs of Britain from the 1940s to 2009 – dubbed the ‘historical Google Earth’ – have been made freely available online.

Lighter planes are the future

sc604 — Tue, 16 Dec 2014 15:56:39 +0000

̽��ֱ��study, by the Universities of Sheffield, Cambridge and UCL ( ̽��ֱ�� College London), is the first to carry out a comprehensive life cycle assessment (LCA) of a composite plane, such as the Boeing Dreamliner 787 or Airbus 350, and extrapolate the results to the global fleet.

̽��ֱ��LCA covers manufacture, use and disposal, using publicly available information on the Boeing Dreamliner 787 fuselage and from the supply chain – such as the energy usage of the robots that construct the planes. ̽��ֱ��study compares the results to the traditional – and heavier – aluminium planes.

Emissions during the manufacture of composite planes are over double those of aluminium planes. But because the lighter aircraft use significantly less fuel, these increased emissions are offset after just a few international flights. Over its lifetime, a composite plane creates up to 20 per cent fewer CO2 emissions than its aluminium equivalent.

Professor in Advanced Materials Technologies at the ̽��ֱ�� of Sheffield, Alma Hodzic, says: “This study shows that the fuel consumption savings with composites far outweigh the increased environmental impact from their manufacture. Despite ongoing debates within the industry, the environmental and financial savings from composites mean that these materials offer a much better solution.”

̽��ֱ��researchers fed the data from the LCA into a wider transport model to gauge the impact on CO2 emissions as composite planes are introduced into the global fleet over the next 25 years, taking into account other factors including population, economic prosperity, oil prices and speed of adoption of the new technology.

̽��ֱ��study – published in the International Journal of Life Cycle Assessment – estimated that by 2050, composite planes could reduce emissions from the global fleet by 14-15 per cent relative to a fleet that maintains its existing aluminium-based configuration.

Professor in Energy and Transport at UCL, Andreas Schäfer, explains: “ ̽��ֱ��overall emissions reduction for the global fleet is lower than the reduction for an individual plane, partly, because by 2050, not all the fleet will be of composite construction. New planes entering the fleet before 2020 could still be in use by 2050, but the faster the uptake of this technology, the greater the environmental benefits will be.”

Dr Lynette Dray from Cambridge's Department of Architecture agrees: “Given that global air traffic is projected to increase four-fold between now and 2050, changing the materials used could avoid 500 million tonnes of CO2 emissions in 2050 alone, a value that roughly corresponds to current emission levels.”

Professor Hodzic adds: “ ̽��ֱ��industry target is to halve CO2 emissions for all aircraft by 2020 and while composites will contribute to this, it cannot be achieved by the introduction of lighter composite planes alone. However, our findings show that composites – alongside other technology and efficiency measures – should be part of the picture.”

A global fleet of composite planes could reduce carbon emissions by up to 15 per cent, but the lighter planes alone will not enable the aviation industry to meet its emissions targets, according to new research.

Given that global air traffic is projected to increase four-fold between now and 2050, changing the materials used could avoid 500 million tonnes of CO2 emissions in 2050 alone, a value that roughly corresponds to current emission levels

Lynette Dray

indianadinos

Airbus A350 XWB MSN001

̽��ֱ��text in this work is licensed under a Creative Commons Licence. If you use this content on your site please link back to this page. For image rights, please see the credits associated with each individual image.

Yes

Licence type:

Attribution-Noncommercial-ShareAlike

Attack of the Zeppelins

tdk25 — Fri, 23 Aug 2013 05:00:34 +0000

̽��ֱ��battle to bring down the Zeppelins during World War I is being revisited in a new documentary which explains how these supposed floating death-traps successfully brought terror to Britain’s skies.

Attack Of ̽��ֱ��Zeppelins, which aired on Channel 4 on Monday, 26 August, and is now available on 4OD, follows ̽��ֱ�� of Cambridge engineer Dr Hugh Hunt as he examines the science behind the Zeppelins’ success, and their ultimate defeat.

Among other revelations, the programme shows how the unlikely use of cows’ intestines became so critical to German plans to bomb the British public, that sausage-making became illegal in areas under German control!

Hunt also tells the story of how British engineers came up with new ideas to stop the giant airships, after it became all too apparent that shooting at them with machine-guns was not enough.

In addition, the film records a remarkable personal discovery, as he finds out quite by chance that the man behind the decisive innovation which won the battle was none other than his own Great Uncle.

It is not the first time that Hunt has revisited remarkable feats of wartime engineering. His previous investigations have looked at how some of the best-known exploits of World War II, such as the Dambusters Raid and the Great Escape, were accomplished.

For his latest project, however, he turned instead to the air raids of World War I, which foreshadowed the Blitz 30 years later, and shocked the British public by taking war to the civilian population for the first time in centuries.

“One of the most intriguing things about the Zeppelins is that we don’t have a huge amount of information about how they were built, nor about how they were destroyed,” Hunt said.

“You would think that it’s pretty straightforward given the Hindenburg disaster in 1937. But while shooting down a massive hydrogen balloon sounds pretty easy, actually it was quite the opposite. For the best part of two years, these things were able to fly over Britain, dropping bombs and causing havoc. We wanted to know more about how that worked, and how they were beaten.”

Conceived as a way to break British civilian morale, the Zeppelin raids never caused casualties on anything like the scale that would have been necessary to change the course of the war. Nevertheless, for civilians who witnessed them, the attacks, which began in January 1915, were a shocking experience.

Over the next two years, London’s East End and other towns and cities in east and southern England, such as Hull, King’s Lynn, and Great Yarmouth, found themselves targets. Silent and difficult to anticipate, the Zeppelins were a new kind of terror weapon which the British were slow to counter. When the raids ended in 1917, 77 of the 115 German airships had been shot down, but 1,500 British citizens had been killed in air raids.

Winston Churchill himself had written off the Zeppelins as “enormous bladders of combustible and explosive gas”, but in practice they proved exceptionally difficult to bring down. For the film, Hunt decided to investigate why, by firing at bags of hydrogen himself.

“If you shoot a bullet at a balloon of hydrogen, all you get is a small hole,” he explained. “There were 50 thousand cubic metres of gas in a Zeppelin, and by putting a few holes in it, all you were doing was depriving it of a few cubic metres. It barely made any difference.”

̽��ֱ��documentary also reveals the ingenious and slightly gruesome method by which hydrogen, which is a difficult gas to contain into the first place, was held by Zeppelins in the first place. Records suggested that the Germans used the intestines of cows, but it was not clear how this was achieved.

To find out, Hunt and his colleagues took the unlikely measure of visiting a sausage factory in Middlesbrough, where cow’s intestines are used to make sausage skins. By following the method used there, they worked out that by making the skins wet, stretching them, and allowing them to dry again, they were bonded together to form ideal vessels for hydrogen gas.

There was a drawback for the German public, however, as it took the guts from more than 250,000 cows to make a single airship. ̽��ֱ��animal’s intestine became so precious that German sausage making was temporarily forbidden.

̽��ֱ��film also revisits the method by which the British finally put an end to the Zeppelin threat, by alternately firing explosive and incendiary bullets into the balloons. By doing so, they were able to pierce the balloon first, enabling oxygen to mix with the hydrogen, before setting the lethal mixture on fire.

One final revelation for Hunt was that the designer of the incendiary bullets that set the Zeppelins alight was none other than his own Great Uncle, Jim Buckingham.

“I remember my father talking about an Uncle Jim who had worked on tracer bullets later, in World War II, but for some reason I had never made the connection,” he said. “It wasn’t until I was chatting to my cousin about it that it clicked, and I realised that we were talking about the same person.”

Attack Of ̽��ֱ��Zeppelins will be shown on Channel 4 at 8pm on Monday, 26 August. For more information, visit: http://www.channel4.com/programmes/attack-of-the-zeppelins

For more information about this story, please contact Tom Kirk, Tel: 01223 332300, thomas.kirk@admin.cam.ac.uk

An investigation into how the Zeppelins worked, and how they were defeated, led by Cambridge engineer Hugh Hunt, forms the subject of a Channel 4 documentary.

Shooting down a massive hydrogen balloon sounds pretty easy. Actually it was quite the opposite.

Hugh Hunt

Channel 4 / Windfall films

Screenshot from Attack Of ̽��ֱ��Zeppelins, which airs on Monday

This work is licensed under a Creative Commons Licence. If you use this content on your site please link back to this page.

Yes

How wings really work

lw355 — Wed, 25 Jan 2012 09:00:22 +0000

It’s one of the most tenacious myths in physics and it frustrates aerodynamicists the world over. Now, ̽��ֱ�� of Cambridge’s Professor Holger Babinsky has created a 1-minute video that he hopes will finally lay to rest a commonly used yet misleading explanation of how wings lift.

“A wing lifts when the air pressure above it is lowered. It’s often said that this happens because the airflow moving over the top, curved surface has a longer distance to travel and needs to go faster to have the same transit time as the air travelling along the lower, flat surface. But this is wrong,” he explained. “I don’t know when the explanation first surfaced but it’s been around for decades. You find it taught in textbooks, explained on television and even described in aircraft manuals for pilots. In the worst case, it can lead to a fundamental misunderstanding of some of the most important principles of aerodynamics.”

To show that this common explanation is wrong, Babinsky filmed pulses of smoke flowing around an aerofoil (the shape of a wing in cross-section). When the video is paused, it’s clear that the transit times above and below the wing are not equal: the air moves faster over the top surface and has already gone past the end of the wing by the time the flow below the aerofoil reaches the end of the lower surface.

“What actually causes lift is introducing a shape into the airflow, which curves the streamlines and introduces pressure changes – lower pressure on the upper surface and higher pressure on the lower surface,” clarified Babinsky, from the Department of Engineering. “This is why a flat surface like a sail is able to cause lift – here the distance on each side is the same but it is slightly curved when it is rigged and so it acts as an aerofoil. In other words, it’s the curvature that creates lift, not the distance.”

Babinsky is quick to stress that he is far from the only aerodynamicist who is frustrated by the perpetuation of the myth: colleagues have in the past expressed their concerns in print and online. Where he hopes his video will help debunk the myth once and for all is by providing a quick and visual demonstration to show that the most commonly used explanation cannot possibly be correct. ̽��ֱ��original video, created by Babinsky a few years ago using a wind tunnel, has now been re-edited in high quality with a voice-over in which he explains the phenomenon as it happens.

Babinsky’s research focuses on the fundamental aspects of aerodynamics as they relate to aircraft wings, Formula I racing cars, articulated lorries and wind turbines. One of his visions is to design a wing that will enable aircraft to fly faster and more efficiently. Using a massive wind tunnel within the Department of Engineering, Babinsky and his team have been modelling the shockwaves that are created on aircraft wings and that restrict the plane’s top speed.

̽��ֱ��newly released video will support lectures Babinsky will be giving as part of a series of ̽��ֱ�� of Cambridge Subject Masterclasses aimed at Year 12 school children: “It’s important to put out this video because when I give this lecture to school kids I start by giving the wrong explanation and asking who has heard it and every time 95% of the audience puts their hand up. Only a handful will know that it is wrong.”

A 1-minute video released by the ̽��ֱ�� of Cambridge sets the record straight on a much misunderstood concept – how wings lift.

I start by giving the wrong explanation and asking who has heard it and every time 95% of the audience puts their hand up. Only a handful will know that it is wrong.

Professor Holger Babinsky

Airflow across a wing

Holger Babinsky

Air flow across a wing

This work is licensed under a Creative Commons Licence. If you use this content on your site please link back to this page.

Yes

Bombs away: ̽��ֱ��Dambusters bounce back

bjb42 — Sat, 30 Apr 2011 04:00:40 +0000

Simulated bouncing “bombs” were constructed from scratch, then dropped by aircraft flying just 60 feet above the surface of a lake in British Columbia, Canada, to destroy a 130-feet wide dam. ̽��ֱ��project was led by Dr Hugh Hunt, from the Department of Engineering, ̽��ֱ�� of Cambridge, and will be the subject of a Channel 4 documentary – “Dambusters: Building ̽��ֱ��Bouncing Bomb” – at 8pm on Monday, 2 May.

To date, nobody has examined the engineering complexity of the remarkable raid, which took place on the night of 16/17 May, 1943, or managed to prove how it was successfully carried out.

Originally known as “Operation Chastise”, and later immortalised in the 1955 film, ̽��ֱ��Dam Busters, the raid sent Lancaster bombers from RAF no. 617 squadron to fly dangerously low over reservoirs in the strategically important Ruhr Valley in order to bomb the Möhne and Edersee Dams. At the time, both were thought to be almost impregnable to conventional bombing raids.

Under intense anti-aircraft fire, the crews dropped “bouncing” bombs, specially designed by the British engineer, Sir Barnes Neville Wallis, to skip across the water en route to the target. If released at the right moment, these could bypass the torpedo nets the Germans had placed to defend the dam. On reaching the dam wall, they sank to a predetermined depth and exploded.

While the mission itself has gone down as one of the most iconic episodes in Britain’s wartime story, few details about how the bouncing bomb was built remain. Most of Barnes Wallis’ original calculations, designs and results were lost; many of them in a flood in the 1960s. ̽��ֱ��physics of “richochet” (the bouncing of objects on water) is quite well understood but actually doing it has been a different matter.

“There’s no massive mystery in a theoretical sense, but the fact that no-one has been able to repeat the mission meant that there was no-one alive who knew whether it was difficult, easy, or indeed possible,” Dr. Hunt said. “ ̽��ֱ��question was really finding out whether anyone could do it again.”

Drawing heavily on a 1976 paper by his Cambridge colleague, Professor Ian Hutchings, which proposed a model for how the bouncing bomb was made, Hunt set to work trying to build one. He started by firing cricket balls from a bowling machine at the Jesus Green open air swimming pool in Cambridge to test Hutchings’ theories. This was gradually scaled up, until much larger imitation bombs were being fired out of a compressed air cannon.

̽��ֱ��team of dam engineers, explosive experts, mechanics and pilots then headed for Mackenzie in British Columbia, Canada, where a 30-feet high and 130-feet wide dam was specially built to see if the Dambusters raid could be reconstructed.

Before that could happen, however, the group had to negotiate several engineering hurdles. A mechanism had to be designed to carry the bomb and the device itself had to be balanced so that it did not vibrate.

̽��ֱ��biggest challenge was making the bomb itself spin. Barnes Wallis’ original device bounced cleanly and was stabilised because it was rotating at a rate of 500 revolutions per minute (RPM) when it hit the water. For the reconstruction team, to do the same thing meant either repeating the inventor’s strategy of spinning it during the flight – which is logistically complex – or setting it spinning on the runway before takeoff, which might lead to the RPMs falling too low before the aircraft reached the drop zone.

̽��ֱ��group opted to set their bombs spinning before take off. To keep them turning, Hunt, who worked closely with his PhD student, Hilary Costello, designed a shield, rather like the windscreen on a vintage sports car. This was custom-designed to deflect air around one side of the device. ̽��ֱ��movement of the air kept the bomb spinning so effectively that it was still turning at 1,000 RPM when it was dropped.

̽��ֱ��shield was developed and optimised with the aid of the Wind Tunnel in the aerodynamics laboratory in Cambridge, primarily with a view to spoiling the aerodynamic lift due to spin (Magnus effect) so that there was no risk of the bomb rising up and hitting the plane on release. During these tests, the team found that a cut-down version of the shield helped significantly to keep the bomb spinning during flight

Even then their problems were not over. During the first drop in Canada, the bombs were tangled up on release and the mission looked to be a failure. “It was one of those things,” Hunt said. “ ̽��ֱ��theory looks nice and easy , but once you do things for real, it’s never that simple. There were a lot of glum faces.” Further inspection revealed that a release cable was five inches too short. This could not be lengthened, but two tie bars were replaced - each measuring 2.5 inches longer. On the next flight, the bomb bounced perfectly and after a few more test runs the dam was destroyed.

Not everything could be reconstructed faithfully. So few Lancaster bombers survive that the team had to use World War II vintage DC4 aircraft instead. ̽��ֱ��dam itself was also one third the scale of those attacked in Germany – although the rest of the project was scaled accordingly to make it realistic.

For Hunt, however, this only served to emphasise the remarkable nature of what Barnes Wallis and the pilots of 617 squadron, achieved. Of the 133 hand-picked air-crew in 1943, which comprised pilots of many nationalities, including members of the Canadian, Australian and New Zealand air forces, 53 lost their lives in the Dambusters raid.

“Our pilots had no-one shooting at them, the engineers could use things like bowling machines to test their theories, and the whole thing was only at one third scale – and even then it was hard enough,” Hunt said. “You compare that with the original challenge – for Barnes Wallis and for the pilots – and you realise what an amazing achievement it was.”

̽��ֱ��daring Dambusters raid of World War II, in which RAF pilots famously used a bouncing bomb to breach two German dams, has been recreated by a Cambridge-led team to prove how the amazing feat was achieved.

Our pilots had no-one shooting at them, the engineers could use things like bowling machines to test their theories, and the whole thing was only at one third scale – and even then it was hard enough.

Dr Hugh Hunt

Windfall films

A DC4 drops a bouncing bomb in the reconstructed Dambusters operation.

This work is licensed under a Creative Commons Licence. If you use this content on your site please link back to this page.

Yes