Rolls-Royce Announces Successful Run Of UltraFan Technology Demonstrator To Maximum Power
The title of this post, is the same as that of this press release from Rolls-Royce.
This is the sub-heading.
Rolls-Royce today announces it has successfully run its UltraFan® technology demonstrator to maximum power at its facility in Derby, UK. The initial stage of the test was conducted using 100% Sustainable Aviation Fuel (SAF).
These are the first four paragraphs.
This is an important milestone for the UltraFan demonstrator, which was successfully tested for the first time earlier this year. Since then, the UltraFan team has been gradually increasing the power as part of the rigorous testing regime and the demonstrator has performed in line with our expectations. The results of the test will provide us with valuable learning and data, which our teams will now take away and continue to analyse.
This achievement reinforces our confidence in the suite of technologies that has been developed as part of the UltraFan programme. Confirming this capability is a big step towards improving the efficiency of current and future aero-engines as UltraFan delivers a 10% efficiency improvement over our Trent XWB, which is already the world’s most efficient large aero-engine in service. In total that’s a 25% efficiency gain since the launch of the first Trent engine.
UltraFan’s scalable technology from ~25,000-110,000lb thrust also offers the potential to power the new narrowbody and widebody aircraft anticipated in the 2030s.
As part of the UltraFan development programme we have identified a number of technologies that are potentially transferable to our current Trent engines, which will provide our customers with even greater availability, reliability and efficiency.
These are my thoughts.
What Is UltraFan?
UltraFan has a section in the Wikipedia entry for the Rolls-Royce Trent engine, where these are the two opening paragraphs.
After the Advance comes the UltraFan, initially aimed to be ready for service from 2025. A geared turbofan with a variable pitch fan system that promises at least 25% improvement in fuel burn, the UltraFan aims for a 15:1 bypass ratio and 70:1 overall pressure ratio.
The Ultrafan keeps the Advance core, but also contains a geared turbofan architecture with variable-pitch fan blades. As the fan will vary pitch to be optimised for each flight phase, it won’t need a thrust reverser. Rolls-Royce will use carbon composite fan blades instead of its usual hollow titanium blades, and along with new material adoption will save 340 kg (750 lb) per engine.
This is a bit different from previous engines.
Variable-Pitch Fan Blades
Variable Pitch Fan has its own Wikipedia entry, where these are the two opening paragraphs.
A variable pitch fan is similar in concept to that of a variable-pitch propeller and involves progressively reducing the pitch (or blade angle) of the fan on a turbofan as the engine is throttled. Although variable pitch fans are used in some industrial applications, the focus of this article is on their use in turbofan engines. No production engine uses such a feature; however, it will likely be required on at least some of the next generation of high bypass ratio turbofans.
One of the methods used to reduce Thrust-specific fuel consumption is to improve Propulsive Efficiency. This involves reducing the effective jet velocity of the engine by reducing specific thrust. This, in turn, reduces the optimum fan pressure ratio required and consequently the cold nozzle pressure ratio. At cruise flight speeds the nozzle is choked and the fan working line is fairly steep and linear. However, at low flight speeds the ram pressure rise in the air intake is so low the nozzle is well un-choked. Consequently, the fan working line is highly curved and well to the left of the cruise flight speed working line, potentially reducing the fan surge margin to a dangerous level, particularly at lower throttle settings. Readers unfamiliar with surge lines, working lines, etc. should read the Wikipedia article on Compressor map.
The extract says that no production engine uses this feature. So will UltraFan be the first?
Variable pitch fan blades seem to offer two advantages; better efficiency and lower weight. If the reliability is acceptable, then that must be a winner.
No Thrust Reverser
This sentence is also in the Wikipedia entry for Variable Pitch Fan.
One advantage of the variable fan option is that varying the fan pitch offers the possibility of reversing engine thrust without the need for heavy blocker doors, cascades, etc.
It does look like the UltraFan will be a lighter engine, than its predecessor.
Composite Fan Blades
Composite Fan Blades were tried in the 1960s for the Rolls-Royce RB211 engine.
But they failed and were replaced by titanium blades.
At the time, I was at Liverpool University and John Wilkinson was a fellow student.
John’s father was the manager of a Tesco store in Derby.
That Tesco store had a nice line in selling out-of-date chickens and turkeys to Rolls-Royce to test the engines for bird strikes.
Improving The Engine’s Efficiency
This is the second paragraph of the press release.
This achievement reinforces our confidence in the suite of technologies that has been developed as part of the UltraFan programme. Confirming this capability is a big step towards improving the efficiency of current and future aero-engines as UltraFan delivers a 10% efficiency improvement over our Trent XWB, which is already the world’s most efficient large aero-engine in service. In total that’s a 25% efficiency gain since the launch of the first Trent engine.
Note.
- The Trent engine was first run in 1990 and has improved 25 % since.
- The Trent XWB engine was first run in 2010 and has improved 10 % since.
The increase in efficiency appears to be linear.
A Saleable Design
This is the third paragraph of the press release.
UltraFan’s scalable technology from ~25,000-110,000lb thrust also offers the potential to power the new narrowbody and widebody aircraft anticipated in the 2030s.
If that means that an UltraFan can power an aircraft as small as an A320, then that is sensational, as it will give Rolls-Royce access to the A320/Boeing 737 market, where they have virtually no sales.
UltraFan Is About A Suite Of Technologies
This is from the second paragraph of the extract.
This achievement reinforces our confidence in the suite of technologies that has been developed as part of the UltraFan programme.
And this is the fourth paragraph.
As part of the UltraFan development programme we have identified a number of technologies that are potentially transferable to our current Trent engines, which will provide our customers with even greater availability, reliability and efficiency.
As you learn more about your future project, why not apply that knowledge to current projects.
Running On SAF Is Part Of The Testing
I’m reassured that testing of the technology using Sustainable Aviation Fuel has started early in the program.
This is surely going to be the fuel, that aircraft will use until hydrogen becomes available.
Conclusion
It looks like Rolls-Royce are redefining, what a standard aero engine looks like.
- It will give a 10 % fuel saving over their latest engines launched thirteen years ago.
- The UltraFan engines will save weight and hopefully more fuel.
- It will allow Rolls-Royce to compete in the A320/737 market, where they have no engine at present.
I would watch the share price
The Anonymous Widower 
Whats brilliant about this is how RR keep pushing the boundaries of what can be done with fossil fuelled powered engines. Personally i feel pushing the suppliers of fossil fueled powered engines to keep improving efficiency and reducing pollutants has as much place in the world as encouraging renewables as they shown great ability to innovate everytime the challenge has been thrown down.
Comment by Nicholas Lewis | November 13, 2023 |
I agree! Look at the way Cummins are transforming their business from a diesel one to a zero-carbon one. But having worked for Cummins, zero-carbon fits their customer gets what they want philosophy.
Terex’s new cement trucks are a manifestation of this philosophy.
Comment by AnonW | November 13, 2023 |