Aircraft

World's largest aircraft engine is fully operational and ready to test

World's largest aircraft engine is fully operational and ready to test
Hi, I'm your biggest fan ... The Rolls-Royce UltraFan is the biggest turbofan in history, and it's expected to deliver huge advantages in fuel economy, weight, noise and emissions
Hi, I'm your biggest fan ... The Rolls-Royce UltraFan is the biggest turbofan in history, and it's expected to deliver huge advantages in fuel economy, weight, noise and emissions
View 5 Images
Hi, I'm your biggest fan ... The Rolls-Royce UltraFan is the biggest turbofan in history, and it's expected to deliver huge advantages in fuel economy, weight, noise and emissions
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Hi, I'm your biggest fan ... The Rolls-Royce UltraFan is the biggest turbofan in history, and it's expected to deliver huge advantages in fuel economy, weight, noise and emissions
Moving the UltraFan test demonstrator into the Testbed 80 facility
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Moving the UltraFan test demonstrator into the Testbed 80 facility
Carbon-composite fan blades with titanium leading edges
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Carbon-composite fan blades with titanium leading edges
Covers off and mounted to the rafters, the UltraFan demonstrator is set to begin testing
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Covers off and mounted to the rafters, the UltraFan demonstrator is set to begin testing
The lightweight, large-diameter fan, high-bypass design, power gearbox and high-speed compressor all add up to significant fuel savings
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The lightweight, large-diameter fan, high-bypass design, power gearbox and high-speed compressor all add up to significant fuel savings
View gallery - 5 images

Rolls-Royce says it's finished building the first demonstrator for its massive UltraFan engine, which will eventually hit the skies in airliners to be developed in the 2030s. Testing begins soon, with expectations of a 25% leap in efficiency.

Airliners will continue to burn hydrocarbon fuels into the foreseeable future – there's no clean alternative yet that can give you anywhere near the range and endurance of current long-haulers. So Rolls-Royce is continuing to develop its next-generation UltraFan engine.

This giant blue-bladed turbofan is the first of what will become a whole family of engines for narrow- and wide-body aircraft, ranging from 25,000 lbf to around 110,000 lbf of thrust. Its 140-inch-diameter (3.56 m) fan is nearly 5% bigger than the one in the General Electric GE9X – currently the biggest engine in the airliner class. With a small increase in diameter, though, comes a pretty decent increase in swept area.

The lightweight, large-diameter fan, high-bypass design, power gearbox and high-speed compressor all add up to significant fuel savings
The lightweight, large-diameter fan, high-bypass design, power gearbox and high-speed compressor all add up to significant fuel savings

The UltraFan makes use of Rolls-Royce's new robot-controlled 3D composite manufacturing process, which is now capable of producing the complex shapes needed for the aerodynamics of fan blades. Titanium is still the engineers' pick for the leading edges of the blades, but the rest is carbon composite. This makes it much lighter than the full-titanium fans used in Rolls-Royce's Trent-class engines. This lightweight fan is the key reason why Rolls-Royce has been able to build an engine this big – but on smaller versions, it'll basically free up weight for extra payload and passengers.

The UltraFan also runs a planetary power gearbox between the fan and the compressors at the back, so the fan can run at its optimal slower speed while the compressors run at their optimal higher speed. In earlier testing, the gearbox handled some 65 megawatts (87,000 hp) of power, another aerospace record.

While the fan has an enormous diameter, the turbines within are kept fairly compact, and Rolls-Royce's engineers have made sure a large volume of air goes around the compressor core and straight out the back of the engine, as opposed to being channeled through the core of the engine to drive the compressors. This creates a high bypass ratio, which helps cut down noise by an impressive 35%, and gives the engine a significant boost in fuel efficiency.

Moving the UltraFan test demonstrator into the Testbed 80 facility
Moving the UltraFan test demonstrator into the Testbed 80 facility

Rolls-Royce says the UltraFan will use about a quarter less fuel than its own first-generation Trent engines, making them cheaper to run, longer-range and better for the environment. They capture NOx emissions more efficiently, too, dropping these by around 40% and more or less eliminating particulate emissions altogether. It's designed to run on 100% sustainable aviation fuel to begin with, but Rolls-Royce is also looking into hybrid electrification and hydrogen combustion in the drive toward full decarbonization.

Now that the first tech demonstrator is fully assembled, it's gone to the company's brand new, US$108 million Testbed 80 facility in Derby, UK – the "largest and smartest" test facility in the world, designed and built specifically around the needs of the UltraFan test program, where the team will start putting it through its paces as development continues.

Rolls-Royce | UltraFan Test Programmes

Source: Rolls-Royce

View gallery - 5 images
15 comments
15 comments
MashiachTheReal1
Instead of making it fully electric, they want to put another polluter in the sky!
William Hetzer
While this new engine is all well and good for RR, Pratt&Whitney has been building jet engines with planetary gearboxes for the Airbus NEO fora few years now.
Robt
Fantastic real world engineering that will pave the way for continuing progress such as alternative fuels
A battery powered alternative for the size of aircraft that this engine is designed for would have a range of about ten miles
MarylandUSA
1. It would have been nice to learn its specific fuel consumption. SFC is how you measure a turbine engine's efficiency. In the late 1970s, when I was in the jet engine industry, SFC improved by maybe 1 or 1.5 percent a year. A 25 percent improvement would be huge.
2. I wonder whether Rolls Royce tried to come up with a gearbox-free design. GE tried, but abandoned their design, in (I think) the 1990s.
DavidIngram
Better tech is always good but the GE9X is already so large it is a problem to transport. Even larger may start requiring the aircraft to be built around the engines. Imagine what that could look like. Hey Boeing and Airbus, sharpen your pencils.
Slowburn Fan
Those are insanely impressive numbers. The efficacy improvements look so good, I'm a bit sceptical. Makes me think the numbers were provided by the marketing department.
michael_dowling
MashiachTheReal1 : I'm with you,but there is no way to power a gas turbine engine other than with hydrocarbons. They do make biojetfuel,but nowhere near the volume required. The best bet is H2 for fuel,ideally powering a fuel cell producing power to run electric ducted fans,but that is a few years away.
Nelson Hyde Chick
If over a twenty-year period technology reduces impacts to the environment by 25% on a per capita basis but due to population gain and bringing the poor out of poverty the per capita grows by 50% what has been gained? Nothing, it is a net loss.
Nelson Hyde Chick
Things are going to change, they are really, really going to change, but that change will only be for the worse as long as humanity is allowed to swell by billions more. If over a twenty-year period a human activity's impact is reduced by 25% on account of technology or conservation on a per capita basis but on account of population gain and bringing the poor out of poverty the per capita grows by 50% what has been gained? Nothing, it is a net loss. An example being Boeing’s 787 Dreamliner, which uses 20% less fuel per passenger mile; it takes the commercial aviation fleet twenty years to overturn, so let’s say every airliner is using 25% less fuel per passenger mile in 2050, but with the middle class growing in third world countries and trends continue the airlines will be flying 300% of the air miles they fly today, so even though each airplane will be more efficient, many more of them than there are today will still be spewing 225% of what they are spewing into the environment of what they are spewing today, which is better than the 300% they could be spewing. And to add to that, our wealthy have already started flying into space, and it takes a hundred times the amount of energy to put a pound into orbit as it does to take it to 30,000 feet.
spyinthesky
I have news for you MashiachTheReal1 there is no chance presently anyone could build an electric power train for this size of engine/aircraft so doing so would simply bankrupt you. It clearly states that this as is other new generation designs are designed to move to hydrogen and as and when possible fully electric. RR is of course at the forefront of electric power trains having recently set a world speed record, has recently flown an aircraft on sustainable bio fuel (which id however only produced in relatively small amounts presently) and is actively working on and tested on testbed hydrogen fuelled adapted present generation engines aimed at at potential productions of versions of its future smaller Pearl engines. So it’s doing it’s best within present limits to decarbonise. In the meantime these developments are heade in the right direction and sets the technical basis for moving faster to that goal as technology allows.
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