Clean Sky

Clean Sky Joint Undertaking (CSJU) is a public-private partnership between the European Commission and the European aeronautics industry that coordinates and funds research activities to deliver significantly quieter and more environmentally friendly aircraft.^{[1] [2]} The CSJU manages the Clean Sky Programme (CS) and the Clean Sky 2 Programme (CS2), making it Europe’s foremost aeronautical research body.

Overview

Aeronautics is noted for its capacity to innovate and to change the lives of millions of people. Also, for the complexity of its hardware and systems, which means the research and development cycles in the industry (the time it takes for an idea to get from the drawing board to the market) are very long, typically between 20 and 30 years. The risk associated with the large-scale investment required to drive technological progress is very high. In parallel, the environmental impact of the industry currently accounts for 3% of global man-made carbon emissions and is set to increase substantially in the years to come, as modern societies demand better connection among people, countries and regions. By coordinating the research activities of the industry, the CSJU develops new technologies that would otherwise be beyond the manageable risk of the private sector: it provides the necessary funding to develop and introduce innovations within timeframes that would otherwise be unachievable.

As such, the CSJU is intended to be the body that will be the main contributor in realising the Advisory Council for Aeronautics Research in Europe (ACARE) 2020 environmental goals for the industry. These goals are:

• A 50% reduction in carbon dioxide (CO2) emissions.
• An 80% reduction in mono-nitrogen oxides (NOx) emissions.
• A noise reduction for flying aircraft of 50%.
• Mitigate the environmental impact of the lifecycle of aircraft and related products. (1)

Organization

The CSJU Governing Board, made up of representatives from the industry and the Commission, identifies strategic areas where research and innovation are essential. ‘Calls for Proposals' are then launched depending on the evolving needs of the industry. Small or medium-sized enterprises (SMEs), industrial leaders, universities, and professional research organisations respond to the calls with detailed plans for research activities and an outline of the funding that they will require to develop their new technologies. To guarantee an efficient allocation of resources, the applications are evaluated by a panel of independent external experts who advise the CSJU on the proposals with the best potential. The winning proposals then receive funding and other support from the CSJU. The initial Clean Sky Programme, which runs from 2008-2016, has a budget of €1.6 billion. Half of this was provided by the European Commission’s Framework Package 7 Research and Innovation Programme and the other half was provided by financial and in-kind contributions from the industry leaders.

Research areas

The strategic areas where research and innovation are essential are called Integrated Technology Demonstrators (ITDs). There are six of them, each one co-led by two industry leaders that are committed for the full duration of the programme:

Green Regional Aircraft

Green Regional Aircraft (GRA): Co-led by Airbus Group and Alenia. This ITD focuses on small, low-weight aircraft.

Smart Fixed Wing Aircraft

Smart Fixed Wing Aircraft (SFWA): Co-led by Airbus and SAAB. This ITD focuses on wing technologies and configurations covering large aircraft and business jets.

Green Rotorcraft

Green Rotorcraft (GRC): Co-led by AgustaWestland and Airbus Helicopters. This ITD focuses on innovative rotor blades, integration of diesel engine technology and advanced electrical systems for elimination of noxious hydraulic fluids.

Sustainable and Green Engines

Sustainable and Green Engines (SAGE): Co-led by Rolls-Royce and Safran. This ITD focuses on novel configurations such as open rotors and intercoolers.

Systems for Green Operations

Systems for Green Operations (SGO): Co-led by Liebherr and Thales. This ITD focuses on electrical aircraft equipment, system architectures, thermal management and capabilities for greener trajectories.

Eco-Design

Eco-Design (ED): Co-led by Dassault Aviation and Fraunhofer Gesellschaft. This ITD focuses on mitigating the environmental impact of the design, production, withdrawal, and recycling of aircraft by optimising material and energy use.

Complementing the six ITDs is the Technology Evaluator (TE). Once the new technologies have been developed and integrated into a test model or aircraft, the TE assesses the environmental improvements by carrying out demonstration activities and test flights and comparing the results with aircraft that have not been equipped with the new technologies. The difference in fuel saved, noise emitted etc. is the extent of the success of the technology.

Achievements

Examples of hardware that have been developed with the support of Clean Sky:

• Open rotor: Engine intended to power the single-aisle jets that will enter service in 2025-2030.
• Open Rotor Blade: Blade intended for engines powering the single-aisle jets that will enter service in 2025-2030.
• Airbus A340-300 BLADE (Breakthrough Laminar Aircraft Demonstrator in Europe): An Airbus A340-300 flight test aircraft, adapted to demonstrate the potential of Natural Laminar Flow wing technology developed in Clean Sky SFWA. BLADE is a pan-European project on track for first flight in 2017.
• Droop nose demonstrator: This demonstrator is the 1.1 leading edge of a regional A/C for enhanced high-lift performances. The droop nose demonstrator is thought as a technology platform enabling full morphing capabilities, embedded CNT (Carbon nanotube) based ice-protection system, OF (Optical fibres) for strain measurement, temperature sensors, SMA (Shape-memory alloy) based internal patch actuators, SJ (Synthetic jets) for active flow control.
• High Compression Engine Model: A new technology to provide a sustainable alternative to the classic turbine engine, reducing both fuel consumption and emissions.
• Smart flap composite load introduction rib: Full scale composite load introduction rib of a smart flap for DAV business jet application developed with resin transfer moulding manufacturing technology. This load introduction rib, involving the main structural parts of a flap, demonstrates the potential of low-cost, low-weight, low-complexity composite flaps.
• HEMAS actuator: Fault tolerant Electromechanical Main Rotor Actuator including a safety clutch. The HEMAS System is enabling hydraulic-free, more electric helicopter architectures.
• Fuel Injector: An early fuel injector from the Rolls-Royce technology for the Clean Sky SAGE 6 lean burn programme.^[3]
• H1 Part 6: titanium fan wheel: New generation of lightweight environmentally friendly fan wheel of an air cooling unit manufactured by additive manufacturing SLM technology which provide an alternative route to conventional methodologies (bar machining).
• Morphing flap two-bay prototype: Smart structure enabling the camber-morphing of a wing flap segment.
• PRIMARY In-flight Icing detection system: Safely detects the presence of atmospheric conditions that might be conducive to ice build-up on the aerodynamic surfaces of an aircraft.
• Electronic Power Module: A modular smart power converter with flexible power management for electric aircraft.
• Solid State Power Controller enhanced with high-frequency voltage chopping capability for Electrical Energy Management strategy implementation: The overall generator weight can be reduced by up to 10% due to the removal of the 5-minute capacity overload.
• GKN Scoop Intake with integrated electro-thermal ice protection and acoustic attenuation: ECS air intake with integrated electro-thermal ice protection and acoustic attenuation technology. Tested in GKN Icing Wind Tunnel in 2011.
• Annulus Filler: The composite Annulus Filler is located between the fan blades and it directs the airstream to ensure optimal fan blade efficiency.
• Green PU Seating cushion (Head Rest): Head rest of a three part seating cushion system. 22 weight% bio based flexible polyurethane foam without a flame retardant.
• Seamless Morphing Leading Edge Demonstrator: Design of an actuation system that could deform a morphing leading edge seamlessly.
• Nacelle Composite Component made with a liquid resin infusion process and cured on a heating tool: Nacelle composite part made of epoxy resin and carbon fibre by using liquid resin infusion on a heating tool.
• Reference part of Demonstrator K1: Part of the radio rack section. It is made of ALUMINIUM 2024-T42.
• IAI Part 1 of demonstrator K1: Part of the radio stack section. It is made of Magnesium Elektron 43, which leads to a 20-30% weight reduction.

Clean Sky 2

Following the success of the initial Clean Sky Programme, its successor, Clean Sky 2,^[4] was launched in 2014(2) as part of the Commission’s Horizon 2020 Research and Innovation Programme. Clean Sky 2 aims to be the main contributor to the Commission’s Flightpath 2050 goals set by ACARE, which are more ambitious than those of the initial Clean Sky Programme.

These goals are:

• A 75% reduction in carbon dioxide (CO2) emissions.
• A 90% reduction in mono-nitrogen oxides (NOX).
• A noise reduction of flying aircraft of 65%.
• Mitigate the environmental impact of the lifecycle of aircraft and related products by designing and manufacturing aircraft to be recyclable.(3)

Clean Sky 2 will also contribute to maintaining global leadership in European aeronautics. As such, Clean Sky 2 will require a larger membership, a bigger budget, and research activity in a wider range of areas.

Research areas

• Three Innovative Aircraft Demonstrator Platforms (IADPs), for Large Passenger Aircraft, Regional Aircraft and Fast Rotorcraft, developing and testing flying demonstrators at the full aircraft/vehicle level;
• Three Integrated Technology Demonstrators (ITDs), looking at airframe, engines and systems, using demonstrators at major integrated system level;
• Two Transverse Activities (Small Air Transport, Eco-Design), integrating the knowledge of different ITDs and IADPs for specific applications and enabling synergies to be exploited between different platforms through shared projects and results;
• The Technology Evaluator (TE), monitoring and assessing the environmental and societal impact of the technologies developed in the IADPs and ITDs.

References

External links

• Clean Sky Joint Undertaking
• ACARE Advisory Council for Aeronautics Research in Europe
• Framework Package 7 Research and Innovation Programme
• European Commission Horizon 2020 Research and Innovation Programme