Sixth Sense
The Eco-Design ITD focuses on the life-cycle of an aircraft, from early design and raw materials to its retirement from service
Eco-Design is the sixth category in the European Commission's Clean Sky recently launched programme of integrated technology demonstrators (ITDs), its overall aim being to minimise an aircraft's "cradle-to-grave" lifecycle impact on the environment, and to do so without compromising performance and economics.
Eco-Design is subdivided into Eco-Design for Airframe (EDA) and Eco-Design for Systems (EDS). A budget of Euro116 million ($185 million) is assigned to the seven-year programme, of which Euro79 million is destined for EDA, and Euro37 million for EDS. Half of the total will be provided by the commission itself, and the remainder by participating organisations.
Airframe
EDA will put into practice the fourth "goal" of ACARE's environmental challenge: "To make substantial progress in reducing the environmental impact of the manufacture, maintenance and disposal of aircraft and related products". In practical terms, EDA aims to minimise lifecycle "inputs" such as raw materials, non-renewable materials, energy and natural resources. EDA also seeks to reduce by-product "outputs" including heat, noxious fluid or gas effluents and solid waste. Where such by-products do occur, emphasis is placed on recycling.
The programme will involve at least nine major contracted organisations. Together with co-leaders Dassault Aviation and Fraunhofer the partners will initially develop and investigate new technologies and industrial processes from 2009 to 2012.
Dassault will investigate new materials and surface treatments, while Fraunhofer will focus on composites, developing a "virtual factory" and end-of-life management. The other participants and examples of their research include: Agusta Westland (structural diagnostic/prognostic, long-life airframe structures) Airbus (cabin interiors) Alenia (materials recycling, elimination and storage) EADS-CASA (optimised manufacturing processes and long-life structures) Eurocopter (eco-friendly materials and surface treatments) Liebherr (new composite, metallic and thermoplastic materials) and Safran (metallic materials and surface treatments).
Yvon Ollivier, technical manager of the Eco-Design ITD, Dassault Aviation, says the teams will concurrently evaluate their research using various demonstrators and partial demonstrators. These will be defined by the beginning of 2011. Subsequent preparation of the airframe and equipment lifecycle demonstrations will be completed by 2012, followed by actual demonstrations occurring in 2012 and 2013.
"One of these, Airbus's cabin interior demonstrator, will involve an actual aircraft fuselage with an interior and wing attachments which will be "manufactured", dismantled and then recycled. Meanwhile, EADS-CASA will be the overall leader for the lifecycle demonstration, while Hellenic Aerospace (HAI) will manage the equipped airframe demonstrator. In addition, Alenia will manage the global demonstrator and Safran will be leader for the equipment demonstration. There will also be a cluster led by Stork to manage the structural partial demonstrators."
Ollivier highlights the challenge to either overcome or circumvent regarding recycling of composites: "A major hurdle is how to develop a green process to extract fibres from old composites and from that to produce new composite material. The other issue is that carbon fibre itself is not a renewable material and therefore a challenge for EDA teams will be to define an alternative, perhaps based on bio-fibres."
Eco-Design for Systems
The second part of the ITD - EDS -focuses on developing systems architectures for small aircraft that maximise use of oil-less electrical transmission and actuation (particularly power-by-wire). In short, EDS aims to reduce or eliminate the need for hydraulic and other non-renewable and noxious fluids and materials in the aircraft. In turn, this will result in eco-benefits especially during aircraft maintenance and at the end-of-life stages when the hydraulic fluids are drained.
"While an all-electric configuration with oil-less electro-mechanical actuation - as opposed to conventional hydraulic actuation - is suitable for smaller business jet and regional aircraft, it is not sufficiently mature to be implemented for large airliners, due to the high power requirements," says Ollivier.
In addition to eliminating harmful fluids, the use of electricity as the only media during aircraft operation would permit flexible energy management such as "intelligent" load-shedding, power regeneration on actuators and the sharing of an electrical control unit over several actuators. Moreover, adoption of power-by-wire would reap benefits in terms of power efficiency and reductions in fuel consumption, which will consequently reduce overall CO2 and NOx emissions.
He adds: "With an all-electric system there are hot-spots, which when coupled with the low thermal conductivity of surrounding composites, could become more severe. We therefore need to solve the problem of achieving thermal management without the aid of an oil-loop to dissipate the heat in combination with heat exchangers."
As with EDA, EDS will involve the aircraft manufacturers, AgustaWestland, Alenia, Dassault and Eurocopter who will jointly participate in the methodology definition and test phases. Other leading participants include: Dassault (power-by-wire flight control system) Fraunhofer (thermal modelling and test activities) Liebherr (subsystem activities for the environmental control system and ice protection) Safran (electrical distribution and utility, fuel and secondary power systems) and Thales (electrical generation and conversion).
The teams will develop thermal and electrical models which will be validated through aircraft-level electrical and thermal ground tests rigs. For example, a large electrical test bench will be developed at Hispano-Suiza's facility at Colombes, France, and thermal tests will be applied to a Dassault Falcon mock-up at Fraunhofer's facility in Pfintzal, Germany. "We need to be sufficiently confident that our virtual aircraft accurately represents a real aircraft, which will enable us to validate our ground test models," says Ollivier.
Source: Flight International
