Search results
Results from the WOW.Com Content Network
The UltraFan aims for a 15:1 bypass ratio and 70:1 overall pressure ratio. [50] The Ultrafan keeps the Advance core, but also contains a geared turbofan architecture with variable-pitch fan blades. The fan varies pitch to optimise for each flight phase, eliminating the need for a thrust reverser. Rolls-Royce planned to use carbon composite fan ...
The bypass ratio (BPR) of a turbofan engine is the ratio between the mass flow rate of the bypass stream to the mass flow rate entering the core. [1] A 10:1 bypass ratio, for example, means that 10 kg of air passes through the bypass duct for every 1 kg of air passing through the core.
The Rolls Royce Ultrafan is the largest and most efficient engine to allow multiple turbine speeds. The turbines behind the main fan are small and allow more air to pass straight through, while a planetary gearbox "allows the main fan to spin slower and the compressors to spin faster, putting each in their optimal zones."
Rolls-Royce Plc aim for a 60:1 pressure ratio core for the 2020s Ultrafan and began ground tests of its 100,000 hp (75,000 kW) gear for 100,000 lbf (440 kN) and 15:1 bypass ratios. Nearly stoichiometric turbine entry temperature approaches the theoretical limit and its impact on emissions has to be balanced with environmental performance goals.
Rolls-Royce are currently developing the Ultrafan which employs much of what is described above. [5] [6] In the 1980s the General Electric GE36 Unducted Fan (UDF), which actually flew on a McDonnell Douglas MD-80, employed two rows of contra-rotating variable pitch fan blades, albeit without any fan casing because it was a prop-fan engine.
The Rolls-Royce Trent 1000 is a high-bypass turbofan engine produced by Rolls-Royce, one of the two engine options for the Boeing 787 Dreamliner, competing with the General Electric GEnx. It first ran on 14 February 2006 and first flew on 18 June 2007 before a joint EASA/FAA certification on 7 August 2007 and entered service on 26 October 2011.
The Trent 900 is an axial flow, high bypass turbofan with the three coaxial shafts of the Rolls-Royce Trent family. The 2.95 m (116 in) fan with swept blades is driven by a 5-stage LP turbine, the 8-stage IP compressor and the 6-stage HP compressor are both powered by a single stage turbine, with the HP spool rotating in the opposite direction of the others.
The Rolls-Royce Trent 7000 is a high-bypass turbofan engine produced by Rolls-Royce, an iteration of the Trent family powering exclusively the Airbus A330neo. Announced on 14 July 2014, it first ran on 27 November 2015. It made its first flight on 19 October 2017 aboard on the A330neo.