6th Gen fighter programme explores new ways of generating massive electric power from conventional engines
Atul Chandra
The United Kingdom’s (UK’s) Future Combat Air System (FCAS) project, known as ‘Team Tempest’ is expected to enter service from the mid-2030s. Along with other international 6th gen fighter programmes currently under way, it is likely to showcase the biggest advances in combat aviation seen in the last five decades.
Launched in 2018, the GBP 1.9-billion project will deliver a next generation combat aircraft known as the Tempest, to replace the Eurofighter Typhoon and Tornado. The core aircraft is expected to combine a whole network of capabilities, such as un-crewed aircraft and advanced data systems. It will be powered by an advanced propulsion system from Rolls-Royce.
Spooling Up
Rolls-Royce is collaborating with the UK Government, the Royal Air Force (RAF), BAE Systems, Leonardo UK and MBDA UK. Other companies involved are Bombardier Belfast, Collins Aerospace in the UK, GE Aviation UK, GKN Aerospace, Martin-Baker, QinetiQ, and Thales UK.
Significant advances in engine technology are expected to spawn an entire range of high-density power systems, for use on 6th Gen manned and unmanned concepts. Such vehicles will have significantly increased levels of electrification, to power not only the usual array of avionics, sensors and communications systems but also weapons, actuation systems and other accessories.
Rolls-Royce has tested a new, twin-spool demonstrator. It features optimised engine start and is fully electric and accelerated. Simultaneous twin shaft electrical generation provides enhanced power offtake capability; power-sharing between shafts enables mission optimisation/extension and surge margin recover. It also has the ability to manage highly dynamic electrical loads and spikes.
Advanced composite manufacturing techniques have made possible an efficient, high temperature engine core, with significantly increased thrust to weight ratio. The new engine will be lighter and more fuel efficient, increasing operational range and endurance.
Rolls-Royce’s innovative, integrated power generation management not only generates more electrical,power, it also distributes it intelligently across multiple high technology systems. This approach reduces the number of energy exchanges, maximising the potential of the gas-turbine as the primary power source. The powerplant provides instantaneous power and improved performance, due to its embedded starter generators and electrical power storage capacity.
In addition to a distortion tolerant fan system, Rolls-Royce is also designing a singular, optimised heat ‘sink’ for cooling. The thermal management system will utilise the gas-turbine as a heat ‘sink’ to recycle thermal energy around the platform, further minimising the thermal signature. This approach removes the need for overboard venting, thereby improving overall system efficiency. The engine will also feature advanced nozzle design and integration which will vastly enhance aerodynamic performance and infra-red signature management.
Forging Ahead
More than 60 technology demonstration activities are currently under way at Team Tempest. Programme partners are aiming to demonstrate and de-risk many of these world-leading processes and technologies in half the time and at significantly lower cost than previous complex combat air programmes. Rolls-Royce had already started to address the demands of the future even before the launch of the Tempest programme.
This began in 2014, when it took on the challenge of designing an electrical starter generator that was fully embedded in the core of a gas turbine engine, now known as the E2SG demonstrator programme. An electrical embedded starter-generator will save space and provide the large amount of electrical power required by future fighters. This will be a major advance over existing aircraft engines, which generate power through a gearbox underneath the engine, which drives a generator. This requires more space within the airframe to make room for the gearbox and generator and also adds moving parts and complexity.
This new Embedded Electrical Starter Generator (E2SG) is now demonstrating its ability to provide unprecedented levels of electrical power. Phase Three of the E2SG programme will involve testing of a novel thermal management system integrated with the overall propulsion system, as well as more electric engine accessories. Rolls-Royce is also developing an intelligent power manager control system. It uses algorithms to make real time intelligent decisions about how to supply the aircraft’s electrical demand. It also optimises other factors like engine efficiency, to reduce fuel burn or engine temperature, thus extending component life.
Rolls-Royce had made a significant investment in the development of a unique test house as part of Phase One of the E2SG programme, where Gas turbine engines could be physically connected to a DC electrical network. Phase Two of the E2SG programme launched in 2017, resulted in a second electrical generator connected to the other spool of the engine, added the ability to intelligently manage the supply of power between all these systems, along with the incorporation of an energy storage system in the electrical network.
Fanning Ambitions
The UK Government is spending more than GBP2 billion on the project over the next four years, as announced in its recent Defence Command Paper. The UK is also keen to add additional partners to the programme. Italy and Sweden joined last year, following the signing of a Memorandum of Understanding (MoU) to collaborate on the project.
During his visit to Tokyo in July, Defence Secretary Ben Wallace and Japanese Defence Minister Nobuo Kishi agreed to accelerate discussions between the UK and Japan on developing sub-systems for a Future Combat Air System. This included intensifying efforts to explore working together on power and propulsion.
The formal start of the programme’s Concept and Assessment phase was signalled by the UK Ministry of Defence’s (MoD) GBP250 million contract with British industry ‘Team Tempest’ partners in July, driving forward the next phase of the programme. The GBP250 million contract was signed with BAE Systems, one of the four founding members of ‘Team Tempest’, which also includes partners Leonardo UK, Rolls Royce and MBDA UK. Wallace said the contract would sustain thousands of jobs across the UK and ensure the UK remained at the top table when it comes to air combat.
The Concept and Assessment phase which is now officially under way will: define and begin to design the future combat air system; mature technologies across the system; invest in the skilled workforce; secure digital and physical infrastructure and tools that underpin cutting-edge digital engineering, data and software-based systems and enable major programme choices by 2024. The contract will see investment in the digital and physical infrastructure on which the programme will be developed, putting it on a ‘digital first’ footing whereby simulated design and testing will significantly reduce costs, time and emissions changing the way future combat aircraft are manufactured.
“Developing the system allows us to drive a revolution in digital development and harness the power of open systems architecture. We are looking forward to working together with UK industry and international partners to create and deliver a system which will keep us safe for decades to come,” said UK Director of Future Combat Air, Richard Berthon. The Concept and Assessment phase contract will support 2,000 jobs of which 800 are based in the North of England, across sites in Warton, Samlesbury and Brough. BAE Systems has flowed collaborative support contracts directly with the core ‘Team Tempest’ partners Leonardo UK, Rolls-Royce and MBDA, which has resulted in creation of jobs in Edinburgh, Luton, Stevenage and Bristol.
According to a report prepared by PWC on behalf of Team Tempest, the ongoing work of the four Team Tempest partners and their supply chains in support of UK combat air activities could contribute in the region of GBP100 billion to the UK economy between 2021 and 2050. The programme could support around 62,000 jobs per year. Since its creation in 2018, Team Tempest had employed more than 1,800 highly skilled engineers and programmers in the UK by 2020 and this was set to increase to 2,500 by 2021.