Very exciting news, but what massive new aircraft is coming down the pipeline that needs this new mega-engine? Curious to see thrust rating figures, but considering the evolution from GE90-115 to GE9X saw a derating of thrust, not expecting to see this top the 100-110k lb thrust range.
If the A350-1000 doesn't have another 20" to spare in ground clearance for the engine, I don't understand the choice of these dimensions by RR.
I'm also not clear on the choice of size, I'll throw out some thoughts.
They have said all along this is a technology demonstrator, not something targeting a specific market segment.
They did have a proposal on paper at least to get onto the 777x, maybe their thinking was driven by that.
If you are trying to show off the gear, maybe it's a good thing to build a demonstration engine for the largest application you can think of.
Next they should be working on a 90" diameter engine to power the 797.
They've pretty much said they will test this engine this year and next, then stand down till if/when they get the engine onto a project going into production.
I don't think we'll see any speculative builds any time soon.
I also don't think we'll see a concrete 797 program for another two years, maybe more.
Boeing's got to get MAX10 and 777X out on the market and get a better understanding of what the regulators want to see in a next gen cockpit.
All this will take time so sort out, IMO.
Fan diameter is fairly easy to estimate based on the bypass ratio and thrust requirement.
A 350cm fan on the Trent Ultrafan has approximately 35% more area than the 300cm fan on the Trent XWB. That puts the bypass ratio at around 13:1 with the same thrust. Many rumours were for a bypass ratio of 14:1.
A summary of RR's goals circa 2014:
According to R-R future programs and technology chief engineer Alan Newby, the new engines represent “the next two major steps in the evolution of the [Trent] family.” The first, he said, dubbed “Advance,” covers a collection of new technologies intended to improve thermodynamic efficiency, while the later UltraFan development will introduce a gearbox to reduce fan speed and raise propulsion efficiency.
The Advance engine will build on the Trent’s “unique” direct-drive turbine architecture and the results of several years of new-technology research, said Newby. He added that the design, which is expected to sport a bypass ratio of more than 11:1 and an overall pressure ratio of more than 60, could enter service soon after 2020.
Expected to follow about five years later, the UltraFan is aimed at offering at least a 15:1 bypass ratio and an overall pressure ratio of more than 70:1. The company suggests that, relative to the Trent 700 powering the Airbus A330, the engines will provide “significant efficiency improvements” of more than 20 percent and 25 percent, respectively. R-R plans to run its first powered gearbox next year and a demonstrator of the engine could fly before 2020.
A big change with the Advance is the core, which “redistributes the workload” between the intermediate- and high-pressure compressors and turbines (IPCs/HPCs and IPTs/HPTs). Newby said that this “good aerodynamic solution” would provide the foundation for future engine generations.
The UltraFan, which could be a stepping stone to an open-rotor design, has a similar “work split,” said Newby, but with an enhanced IP turbine driving the slower fan through a reduction gearbox, which permits deletion of the low-pressure turbine (LPT).
With deliberate product evolution, R-R has taken the Trent XWB engine’s integrated propulsion system and lightweight LTP and married them to a carbon-titanium (CTi) fan and the new core to create the Advance. In turn, the UltraFan retains the Advance core while introducing the geared multi-stage IPT to drive the fan and compressor.
Ref: https://www.ainonline.com/aviation-news ... d-ultrafan
We all know Advance never was made into its own product, although some of its features made it into TXWB and then TTEN. The big workload redistribution work never made it into a production engine, but IIRC it is part of this demonstrator, along with the carbon/titanium fan and the gear.