Flightpath 2050 and the recently unveiled Strategic Research and Innovation Agenda (SRIA) have elaborated CO2-emissions and external noise targets according to chronologically aligned waypoints. For propulsion and power systems the projected cumulative impact of previous Framework Programmes compare favourably to the 2035 target given in the SRIA document. However, if one extends the comparative exercise to include appreciation of SRIA 2050, the goals assigned to propulsion fall short by a significant amount. Until now, no serious consideration has been given to the potential multi-functional benefits afforded by Active Compliant Systems technologies applied to the inlet and cowl (collectively known as 'nacelle'). Targeting a service entry year of 2025+, the MorphElle Project aims to address this aspect, and will thus constitute a body of investigative work that will serve to complement encouraging efforts expended in other projects.
The project's main objective is the design of an adaptive nacelle concept suited to advanced propulsion ideas, and the qualification of numerical experimental work by performing tests on a mechanical test rig. Finally, potential benefits and risks will be analysed and an initial roadmap for resolving the most important issues for implementation, will be communicated. The MorphElle Consortium benefits from a Joint Technical Advisory Committee (JTAC) comprising 10 members: SAFRAN Aircelle, MTU, Airbus, EADS, Alenia Aermacchi, Rolls-Royce Deutschland, ONERA, DLR and CNRS - FEMTO-ST Besançon. The vision of the MorphElle Project is the investigation of ground-breaking technologies to provide a means for physical shape change which will allow adaptive compliant nacelle systems to make a noticeable contribution in reaching the emissions and noise reduction targets beyond the year 2025.
Novel engine nacelles that deform
An EU-funded project is investigating new concepts for engine nacelles and their implementation in next-generation propulsion systems that promise to increase engine performance and decrease acoustic emissions.
To achieve Europe's vision for maintaining global leadership, the Advisory Council for Aviation Research and Innovation in Europe (ACARE) has set ambitious goals to improve air travel by 2050. In particular, ACARE's Strategic Research and Innovation Agenda (SRIA) and its Flightpath 2050 vision deal extensively with carbon dioxide emissions and external noise targets.
Adaptive nacelles that use active compliant system technologies applied to the inlet and cowl offer large potential benefits for achieving these targets. These technologies have not hitherto received a great deal of attention.
Scientists have initiated the EU-funded http://www.morphelle.eu/ (MORPHELLE) (Morphing enabling technologies for propulsion system nacelles) project to further investigate the concept of active nacelles and identify enabling technology. Achieving smooth shape based on elastic materials that can resist aerodynamic loads is one of the main challenges that MORPHELLE is addressing.
Reinforcement of nacelle materials enables them to be stiff and withstand high aerodynamic loads. A promising material for the nacelle is an elastomer reinforced by a metal mesh that except for being stiff should allow large shear deformation.
The nacelle supporting structure will consist of a pressurised tube and a deformable auxetic core. Major focus has been placed on adapting the nacelle shape to multiple flight conditions for improving its aerodynamic performance.
In the first project period the primary objective was to identify requirements for shape adaptation and morphing technologies for different flight conditions. Scientists have performed significant work with regard to investigating the optimal nacelle design for cruise and close to the ground conditions through numerical simulations.
The most promising morphing nacelle concept will be selected for detailed investigation, and its performance will be demonstrated by mechanical testing on a test rig.
Adaptive technologies applied to the nacelle are expected to contribute to the Flightpath 2050 targets of reducing carbon dioxide by 75% and noise emissions by 65%.