Periodic Reporting for period 2 - ROTATOR (Electro-mechanical magnetic blade pitch control)
Reporting period: 2021-06-01 to 2022-11-30
The engine requires accurate control of the angle of the engine blades, and it is this area of control that requires the greatest attention in order to realise the potential fuel savings. Current hydraulic systems transfer fluid to the rotating actuator components in order to control the blade angle, requiring high-maintenance dynamic seals with potential for leakages.
The key areas of innovation in this project centre around the development of a fault tolerant electro-mechanical pitch control mechanism utilizing an ultra-high torque density magnetically geared motor. The system is designed to be fault tolerant (it will remain in operation even after a number of systems failing) from the rotating electrical power transfer device through to the mechanical actuator.
Innovative lightweighting technology will deliver a step-change in motor/actuator weight-saving. A full-size actuator will be built and tested and a number of components and sub-assemblies of the actuator will be vibration
tested at representative temperatures. The coordinated research activities will take the technology from a basic design level to a laboratory demonstrator.
A large number of concepts were considered, including mechanical actuation methods without a screw. The concepts have been studied in terms of their suitability to the application and detailed analysis, modelling and simulation tasks have been undertaken to determine whether the PCM system meets the specification in terms of mass, size, dynamic performance, fault tolerance etc. within the challenging operating environment.
Key component development areas for the PCM include fault tolerant electric drives, rotating electrical power transfer device, magnetically geared motor and development of lightweight mechanical actuation components. Research on the fault tolerant electrical drive uses silicon carbide technology to reduce losses and allow high operating temperatures. This work includes detailed switching models of the proposed drive. The fault tolerant, rotating, contactless power transfer system is under development using high frequency methods of electromagnetic power transfer where complex models and hardware have been developed and tested to understand the operation of the device.
Analytical tools, simulation tools and a digitial twin (a method of using a computer model to predict behaviour and lifetime of physical systems) have been created to support the design of the actuator.
The rotating power transfer device relies on power electronics to transmit the power at high frequency to save weight. The unique environment is challenging for designers, as the electronics must work at high rotational speed and the high forces generated need to be controlled so that the electronic components do not become damaged.
An ultra-lightweight magnetically geared motor has been designed and will be built in 2023. It features lightweighted components developed by the consortium. Lightweighting is a key element of the ROTATOR project. Both metallic and composite parts have been the subject of research in order to provide a light but also reliable and safe mechanism. Novel hybrid composite/metallic manufacturing methods have been investigated and novel methods of manufacturing composite parts for electric motors using a special technique similar to embroidery which allows strength and stiffness to be added to key areas.
A full-scale Pitch Control Mechanism has been designed and most parts in manufacture. The PCM will be built and tested in Sheffield, UK, on a bespoke test-rig designed to replicate the fast rotating environment of an open rotor engine.
The project has reached the conclusion of the detailed design phase and has moved in to the build phase with a large number of components in manufacture and sub-assemblies on test. The PCM is capable of meeting the onerous specification requirements. The project will deliver a full-scale PCM with associated project results arising from both the development of the digital twin and physical measurements on a full-sized demonstrater in 2023. The potential impact of the project remains unchanged. A fully electric PCM will help deliver the goals of the Open Rotor Engine which will transform the aircraft industry in terms of CO2 and NOx reduction. Specifically, it could save 180 million tonnes of CO2 per year - a huge leap for the aviation industry and for the protection of our planet. The project has also been designed to promote job creation and diversity within the Europeamn Union, foster new ideas and intellectual property and develop technologies that will have a wider impact outside the aerospace industry. This approach will promote the technology developed within ROTATOR in driving further reduction in CO2 in the aerospace, marine and automotive transport sectors, and also in renewable energy systems where magnetically geared machines offer the highest annual energy production.