Although Tim Boddy, head of marketing for the program, said “the Trent XWB-84 was always designed with growth potential”, you would have to be a bit of an expert to spot the differences between the XWB-84 and the final production version of its big sister XWB-97.
One of the main tweaks is to the design of the fan system, which includes an inflected annulus to improve flow.
“For the -97 we need to run the fan faster, so we’ve added material to the fan blade, the disc and the fan case to cope with that higher stress,” he said.
A shroudless blade system has also been introduced for the 1st time on a Trent.
However, the nacelle is identical and most of the changes are deep within the engine.
To achieve higher flow, and thrust, engineers have had to design a way to drive the core faster, and that has involved an increase in size of around 5%.
“It’s a subtle change but it’s important to manage down design temperatures,” said Boddy.
“When you are driving up the engine temperature, the trick is to run it hot, reliably and with the minimum amount of cooling air.
By adding high temperature technology, and adding size to the core, these two things together give you a very robust machine.”