Rolls-Royce · Case study
Rolls-Royce Trent XWB
Rolls-Royce's three-spool answer for the Airbus A350. At entry the most efficient large civil engine flying, the Trent XWB showcases an architecture no other manufacturer uses at this scale.
Architecture
The Trent XWB is a three-spool high-bypass turbofan — the Rolls-Royce signature. Where GE and Pratt & Whitney use two concentric shafts, Rolls splits the compression across three: a fan on the low-pressure spool, a separate intermediate-pressure compressor and turbine, and a high-pressure spool. Each spool can run nearer its own optimum speed.
The reward is shorter, stiffer shafts and fewer compressor stages for a given pressure ratio; the price is mechanical complexity and a third set of bearings. The XWB pairs this with a roughly three-metre fan and an overall pressure ratio around fifty.
The cycle
A bypass ratio near nine and a high overall pressure ratio give the Trent XWB excellent cruise efficiency, and at service entry Rolls-Royce could claim it as the most efficient large civil engine in operation. The three-spool layout lets the intermediate and high-pressure compressors each turn at a speed that keeps their stages aerodynamically well matched.
Engineering significance
As the sole engine for the Airbus A350 XWB, the Trent XWB is central to one of the most successful modern widebodies. It is also the clearest in-service demonstration of the three-spool philosophy that distinguishes Rolls-Royce's large engines from its American competitors.
Applications
Airbus A350 XWB
Explore a representative turbofan cycle for this engine class in the interactive console.
Open the simulator →All figures are public-estimated and approximate, given for a representative variant; exact values vary by sub-model and rating. PropulsionLab is an educational project and is not affiliated with any engine manufacturer. Engine names are the trademarks of their respective owners.