GKN

GKN Aerospace has delivered two front and aft rotating frames, developed under the European Union’s (EU) Clean Sky Sustainable and Green Engines 2 (SAGE2) programme, to French aircraft and rocket engine manufacturer Snecma.

Part of Clean Sky’s Open Rotor engine project, the rotating frames were developed to explore open rotor aero-engine designs to reduce 20% fuel consumption and CO2 emissions.

Half-funded by the EU, the project is an aeronautical research programme that aims to develop new environmentally friendly technologies for airplanes and air transport systems.

Various other industry partners are also involved in the project.

The rotating frames work as hubs for two rows of propellers and are placed in the propulsor module at the rear of the engine.

"The challenge with the design and manufacture of rotating frames lies in the fact that they have the geometric complexity of a traditional static turbine structure."

GKN will provide 27 different components for the rotating frame modules, with deliveries scheduled to be completed by the end of this month.

Engine assembly and testing will be conducted at Snecma’s test centre in Istre, France. The test programme is expected to be completed this year.

GKN Aerospace Engine Systems research and technology vice-president Henrik Runnemalm said: "The challenge with the design and manufacture of rotating frames lies in the fact that they have the geometric complexity of a traditional static turbine structure.

"Because they rotate and transfer torque to the propellers, they are safety critical parts with quality requirements, stress concentrations and load paths that are completely different to current static frame designs."

The company said it used new manufacturing technologies and welding and machining techniques to manufacture rotating frames.

The company also developed new non-destructive inspection ways to examine complex geometries of the structures.

Swedish manufacturing technology centre (Produktionstekniskt Centrum – PTC) at Innovatum in Trollhättan, Sweden and other Swedish companies were involved in the development of the project.

Image: GKN Aerospace’s aft rotating frame for the SAGE2 open rotor demonstrator. Photo: courtesy of GKN Aerospace.