Green Regional Aircraft (GRA)

Overview

Regional Aviation is a key factor for creating resources and an efficient air transport system that respects the environment, ensuring safe and seamless mobility, whilst reinforcing Europe's aero-industrial leadership.

A substantial contribution to Clean Sky derives from Regional Air Transport that, to drastically reduce the environmental impact, adopts innovative solutions across several technology domains.

The Green Regional Aircraft ITD (GRA), one of the three vehicle-based ITDs that Clean Sky is developing, delivers and integrates technologies into real regional aircraft configurations - technologies that will be integrated alongside aircraft-level and airframe-based technologies.

GRA, co-led by Leonardo Aircraft Division and Airbus D&S, developed new technologies to reduce noise and emissions, with particular focus around advanced low-weight and high performance structures, incorporation of all-electric systems, bleed-less engine architectures, low noise/high efficiency aerodynamics, and environmentally optimised mission and trajectory management.

The objective of the Green Regional Aircraft ITD is to mature, validate and demonstrate the technologies that best suit the environmental goals set for regional aircraft that will enter service from 2020 onwards.

The environmental forecasts are under regular verification in line with what was presented in the interim assessment and together with the Technology Evaluator platform.

The GRA Demonstration Programme is a combination of ground and flight tests covering various aspects of integration of airframe, systems and engines technical solutions at aircraft level.

The Green Regional Aircraft Demonstration is the core asset of the GRA ITD. It will constitute on the one hand the physical evidence of the extent of achievement of the ACARE environmental targets at aircraft level, and on the other will deliver the final assessment of the relevant technologies allowing the European aero-industry to gather technical information that will be fundamental for the definition of environmentally friendly regional aircraft of the future.

 

Major Demonstrators

Advanced technologies will be assessed through a cost-effective mix of flight and ground tests covering the technical solutions of airframe, systems and engines integration at aircraft level.

Accordingly, flying demonstrators, flight simulators, full scale structural ground tests, large scale aerodynamic and aero-acoustics wind tunnel tests have been utilised.

GRA ITD’s major demonstrations are:
 

Flight Test demos

  • “Low Weight Aircraft” Flight Test demo

Low weight Aircraft

In this Flying Demonstrator an entire (aluminium) section of the upper fuselage has been replaced with an innovative composite panel with an acoustic dampening layer embedded within it, as well as two different technologies for Structural Health Monitoring (SHM).

The flight tests were part of the further technology maturation of the design and manufacturing of advanced composite panels, to prove the CFRP material feasibility and its benefits by insertion on future regional aircraft products.

Flight test targets were very ambitious environmental goals with expected benefits on weight, internal noise, assembly costs and structural health monitoring capability.

The Flying Demonstrator was conceived by Leonardo Aircraft division in cooperation with ATR, who performed the installation of the composite panel into the ATR 72-600 prototype testing aircraft. Fraunhofer Gesellschaft provided optical fibres and piezo electric sensors/actuators for the in-flight measurements.

Furthermore, the flight demonstration was focused around the development and analysis of advanced structure technologies, including new materials and new structural solutions, installed into a large crown panel fuselage embedded with viscous materials to reduce cabin noise, and with an integrated sensors system to validate Structural Health Monitoring (SHM) technologies. 

  • “All Electric Aircraft” Flight Test demo

Flight demonstration, focusing mostly around systems, is enabling the reduction, or even the potential removal, of pneumatic power (from the engine) and of hydraulic power - both used for ice protection functions, for environment conditioning, cabin pressurisation, flight controls, gears extension and retraction, and brakes activation. The idea is to substitute pneumatics and hydraulics with electric compressors in order to drain less energy from the aircraft's main engines.

This will be the first step towards the so-called All Electric Aircraft, where all on-board utilities will use only the electric power output by generators connected to the engine. This target has been achieved through technologies selected for demonstration as planned: Electrical Environmental Control System (E-ECS), Electrical Energy Management (E-EM) dedicating 270 VDC power distribution featuring E-EM control logic, Electro-Mechanic-Actuator (EMA) for rudder and landing gears to be utilized as electrical loads.AIR

To this end, an ATR 72 prototype took to the skies in February 2016 - the second flight test campaign as part of the GRA ITD programme. The aim of this second phase was to test a new electrical power management system, optimising electrical power distribution. This second flight test campaign also performed checks on a new all-electrical air conditioning system.

The performed ‘All Electrical Aircraft’ flight campaign came on the heels of the first flight test campaign of the Clean Sky programme, performed on July 2015 with the same ATR 72 aircraft demonstrator.

The advanced technologies tested on this second flight test campaign have been developed by ATR’s shareholder Leonardo Aircraft division (formerly Alenia Aermacchi) and Clean Sky’s Green Regional Aircraft programme Partners, including Liebherr for the electrical air conditioning system and Thales for the electrical generation. 

 

Ground full-scale demo

There are three main ground full-scale demonstrators: the composite fuselage barrel demo, the composite cockpit demo and the composite wing box demo - all configured for a 90 passenger turboprop.

Advanced metallic and advanced composite (materials, manufacturing) technologies trade-offs have been performed and advanced composite technologies solutions have been selected for the final Demonstrations. This is based on the considerable weight reduction due to more innovative multi-functional layer and multi-layer architectures that can ensure electric conductivity and lightning resistance without additional special items (i.e. with no additional weight). Other factors enabling this reduction include having better acoustic insulation, increased hail impact performance, and the option of using various sensor technologies embedded in the composite to monitor the health status of the structure and report the degradation of its mechanical properties as required.

  • “One Piece Barrel” composite fuselage
  • Image

 

 

 

 

 

 

The OPB demo of a 90-seat advanced turboprop aircraft is based on considerable weight reduction due to more innovative multi-functional layer and multi-layer architectures, a better acoustic insulation, an increased hail impact performance, the option to use various sensor technologies to monitor the health status of the structure and report the degradation of its mechanical properties as required. This component represents the “pioneer” of composite technology application to an important primary structure (the fuselage) for a regional aircraft. 

 

  • “Full composite cockpit"

The size of some of the parts of the aircraft cockpit have been determined by extreme structural requirements (i.e. bird strike, crash-landing or erosion), as well as the need to accommodate the nose landing gear and the avionics bay. Anticipated benefits include structural weight optimisation brought about by utilising high performance materials and complex system integration.

Image

  • Inner Wing Box

The test objective is to monitor the growth of the damage with the SHM system, VID introduction on upper skin (delamination stringer skin) and validation of the design: Demonstrator is at the Final Assembly Line.

 

Wind Tunnel Test

Two advanced configuration aircraft – an advanced geared turbofan 130-seat aircraft and 90-seat turboprop aircraft – will be tested, mainly in wind tunnels.

An open rotor (OR) 130-seat aircraft configuration has been wind tunnel tested, through a Call for Proposals project (WENEMOR), to more intensively investigate the counter-rotating OR technology.

 

Organisation/Structure

The Green Regional Aircraft ITD involved several European beneficiaries among engine manufacturers, system engineering companies, research centres, universities, and small and medium enterprises, to meet demanding weight reduction, energy and aerodynamics efficiency, and a high level of operative performance - in order to be compliant with regard to pollutant emissions and noise generation level targets.

In order to achieve these challenging results, the aircraft has been entirely revisited in all of its aspects.

The GRA technological areas structure is as follows:

  • GRA1 - Low Weight Configuration (LWC)
  • GRA2 - Low Noise Configuration (LNC)
  • GRA3 - All Electric Aircraft (AEA)
  • GRA4 - Mission & Trajectory Management (MTM)
  • GRA5 - New Configuration (NC)

This reflects its transversal nature, by being organised into 5 domains that in turn interface with the other JTI platforms, such as Eco-Design (EDA for Airframe with LWC, EDS for System with AEA), Systems for Green Operation with AEA and MTM, and Sustainable and Green Engines (SAGE) with NC. Though it is necessary to concentrate on some very promising 'mainstream' technologies, it is also important to focus on the benefits of other technologies in an integrated view of their cumulative and reciprocal effects.

 

Members

The GRA activities have been conducted by the ITD co-leaders Leonardo Aircraft division, acting as coordinator, and Airbus Defence & Space.

208 entities have been involved in the project both at Member and Partner level: SMEs represent 52% of the GRA Partnership external envelope.

ITD Leaders involved in the activities are: Fraunhofer Gesellschaft, Liebherr, Rolls-Royce, Safran, and Thales Avionics.

The following Affiliates have been involved: Rolls-Royce Deutschland and Rolls-Royce Corporation (Rolls Royce affiliates), Labinal Power System S.A, Messier-Bugatti-Dowty Vel and Snecma (Safran affiliates), Thales Avionics Electrical System SA (Thales Avionics affiliate), Superjet International (Leonardo affiliate).

In addition, the following Associated Members have been involved: AIrgreen Cluster (Piaggio Aero,Centro Sviluppo Materiali, IMAST, Foxbit, Politecnico Torino, SICAMB, University Bologna, University Napoli, University Pisa), ATR, Cira Plus Cluster (CIRA, Aerosoft, Dema, INCAS, ELSIS), Hellenic Aerospace Industry, Onera.

175 Entities involved through 101 Topics brought to the Green Regional Aircraft programme the essential skills and competences.

Expected benefits

  • CO2 & NOx reduction and perceived noise decrease through: the integration of advanced technologies performing low-weight aircraft configurations, external noise reduction, improved aerodynamic efficiency, the integration of “more electric aircraft” systems architectures, optimised trajectories and mission management.
  • less fuel consumption through lightweight architecture (multifunctional materials, new processes & more efficient use of resources) and efficient energy management
  • increased aircraft availability through more efficient maintenance (repair, longer lifetime etc.)
  • less energy consumption due to “Out of Autoclave” processes
  • reduced joints with less fasteners and sealing by using Single Piece Barrel technology
  • complete integration of fuselage structure (one stiffened component with no mechanical joints) making aircraft lighter and more environmentally friendly by using composite technology.
GRA 1: Low Weight Configuration (LWC) domain

Overview

GRA 1: Low Weight Configuration (LWC) domain

The LWC domain focuses around the development of several technologies aimed at reducing the weight of aeronautic structures that meet the ‘green’ requirements of future regional aircraft. Most promising technologies have been selected through dedicated gates (Technologies Down Selections) at different levels of structural complexity from specimens up to full scale demonstrators (Figure 1).

 

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Figure 1 – GRA ITD - LWC domain: project logic

 

The main technology streams investigated at the beginning of the Project were:

  • Sensors for the detection of accidental damage, environmental effects and the consequent structural degradation during service.
  • Multi-functional layers to improve and integrate in the composite structures the required additional functions (lightning or hail protection, etc.).
  • Nanomaterials to reduce the weight of conventional composites by improving the mechanical characteristics obtained from the nanoparticles dispersed in the resin.
  • Laser welding for integrated advanced metal alloy structures with a view to reducing weight through the removal of connecting devices.

Only technologies which passed the Second Down Selection were applied on full scale demonstrators: ground testing and, in particular, flight testing have been aimed at demonstrating the applicability of the technologies and solutions selected in this domain to future regional aircraft programmes.

 

Major Demonstrators

LWC domain Demonstrators

The final step of the technologies maturation road map is relevant to the technologies demonstration in a realistic experimental environment, representative of the operational conditions expected in flight (TRL 5/6).
 

The Full Scale Demonstrators identified in the LWC domain include (Figure 2):

  • Fuselage Crown Stiffened Panel Demonstrator to be tested in flight
  • Fuselage Barrel Demonstrator to be tested on ground
  • Cockpit Demonstrator to be tested on ground
  • Inner Wing Box Demonstrator be tested on ground

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 Figure 2 – LWC full scale demonstrators

 

  • Fuselage Crown Panel In-flight Demonstrator

Participants

  • Leonardo Aircraft Division (Italy)
  • ATR (France/Italy)
  • FHG (Germany)
  • CIRA PLUS: CIRA (Coordinator – Italy)
  • HAI (Greece)

Objectives

To demonstrate the composite reliability for Regional Aircraft during service and to obtain in-flight validation for the advanced technologies that require data acquired in an actual operating environment (TRL 6) through the following flight tests:

  • flights with pristine Aluminium panel
  • flights with Composite panel in undamaged configuration
  • flights with Composite panel in damaged configuration

Features

The Composite Stiffened Fuselage Crown Panel (Length ≈ 4900 mm; Radius ≈ 1500 mm) has been installed on Section 13 of ATR72 MSN098 Test Aircraft (Figures 3, 4) and includes the following technologies:

  • Advanced multi-functional composite material
  • Damping Acoustic capability (including damping material, accelerometers and microphones)
  • Structural Health Monitoring systems (including optical fibres, piezoelectric actuators/sensors, conventional strain gauges)

 

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Figure 3 – ATR MSN098 before modification

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Figure 4 – ATR MSN098 after modification

Tests

  • Flights with pristine Aluminium panel to evaluate instrumentation functionalities and reference vibro-acoustic measurements – ATR – January 2015
  • Flights with Composite panel in undamaged configuration to evaluate instrumentation functionalities, vibro-acoustic for data correlation and reference SHM measurements (Figure 5, 6) – ATR – July 2015
  • Flights with Composite panel in damaged configuration (Figure 7, 8) to evaluate SHM measurements for data correlation – ATR – July 2015

 

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Figure 5 – Flight test installation for Optical Fibres and Piezoelectric sensors/actuators measurements

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Figure 6– Flight test installation for Acoustic evaluations

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Figure 7 – Impact execution on Aircraft        Figure 8 – Flight with Composite panel

  • Fuselage Barrel Ground Demonstrator

Participants

  • Leonardo Aircraft Division (Italy)
  • HAI (Greece)
  • FHG (Germany)
  • Partner of Project AFLOG (under CfP): OMI (Italy)

Objectives

  • To validate the advanced structural technologies applied at Full Scale Level on Fuselage Barrel including Pressure Bulkheads
  • To demonstrate the achievement of TRL 6 through the following tests performed on the structure including artificial defects and damages due to impacts:
    • Evaluation of Acoustic Transmission Loss (22-Loudspeakers Array around barrel & 20 microphones)
    • Evaluation of the Damping Loss Factor (1-2 shakers & ~ 150 accelerometer positions)
    • Pressurisation test (static & 90000 fatigue cycles)

Features

Full Scale Composite One Piece Fuselage Barrel (Diameter ≈ 3500 mm; Length ≈ 5000 mm) (Figures 9, 10, 11), reproducing the forward fuselage section of a regional aircraft (90 pax) including the following technologies:

  • Pre-preg with damping layer for skin/stringers
  • Thermoplastic for floor beams and windows frames
  • Carbon fibre pre-preg curing out of autoclave for pressure bulkheads
  • Fibre Optics – FOBG
  • Fibre Optics – FOBR
  • Piezoelectric sensors/actuators
  • Wireless Sensors

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Figure 9 – Composite One Piece Fuselage Barrel

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Figure 10 – Fuselage thermoplastic floor grids           Figure 11 – Fuselage thermoplastic window frames

Tests

  • Acoustic Test – Leonardo Aircraft Division – May 2016 (Figure 12)
  • Vibration Test – Leonardo Aircraft Division – June 2016
  • Pressurisation Tests (Fatigue and Static) – Leonardo Aircraft Division – October 2016

 

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Figure 12 – Composite One Piece Fuselage Barrel

 

  • Cockpit Ground Demonstrator

Participants

  • Airbus Defence & Space (Spain)
  • Partners of several Projects (under CfP): PUMA, CRASHING, COMPASS, BME, HYBRIA, DIAAMOND.

Objectives

  • To demonstrate an overall weight reduction in primary structure, improving functionalities of the reference metallic structure
  • To validate the advanced structural technologies applied at Full Scale Level on Cockpit demonstrators
  • To demonstrate the achievement of TRL 5 through
    • vibro-acoustic tests
    • static tests and fatigue tests including damage tolerance
    • EMC test

Features

Full Scale Composite Cockpit (Figure 13, 14) realised in ‘One shot’ multifunctional co-cured stiffened skin including the following technologies:

  • liquid resin infusion both for solid laminates and sandwich primary structure
  • thermoplastic materials
  • damping materials
  • nanomaterial for electromagnetic protection
  • SHM systems

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Figure 13 – Cockpit (view forward)              Figure 14 – Cockpit (view afterward)

Tests

  • Vibro-acoustic test on MT1 – AIRBUS DS – July 2015 (Figure 15)
  • Vibro-acoustic test on MT2 – AIRBUS DS – October 2015 (Figure 16)
  • Static Test (UL) - AIRBUS DS – September 2016
  • Damage tolerance - AIRBUS DS – October 2016
  • EMC Test - AIRBUS DS – December 2016

 

  • Inner Wing Box Ground Demonstrator

Participants

  • AIRGREEN Cluster: Piaggio Aerospace (Coordinator – Italy)
  • CIRA PLUS Cluster: CIRA (Coordinator – Italy)
  • HAI (Greece)
  • Leonardo Aircraft Division (Italy)

Objectives

To demonstrate the achievement of TRL 6 of SHM technologies applied at Full Scale Level on Inner Wing Box through the following tests performed on the structure, including artificial defects and damages due to impacts:

  • Static tests
  • Fatigue tests

Features

Full Scale Composite Wing Box (Composite Test Article Length ≈ 4500 mm; Max wing box Height ≈ 475 mm; Total Length including two dummies structures ≈ 13500 mm) (Figures 17, 18), reproducing the inner section of a wing of a regional aircraft (90 pax) including the following technologies:

  • Piezoelectric sensors/actuators

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Figure 17 – Composite Inner Wing Box Scheme              Figure 18 – Preassembled Inner Wing Box

Tests

  • Damage tolerance – Leonardo Aircraft Division – October 2016
  • Static Tests (LL) – Leonardo Aircraft Division – October 2016

Fatigue and static tests will be performed intruding loads by 12 actuators connected to the metallic dummies (Figure 19).

 

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Figure 19 – Inner Wing Box Demo, Structural dummies and actuators scheme

 

 

GRA2: Low Noise Configuration (LNC) domain

Overview

GRA2: Low Noise Configuration (LNC) domain

The LNC domain addresses several breakthrough technologies (Figure 1):

  • advanced aerodynamics and load control to enhance lift-to-drag ratio at various flight conditions, thereby reducing fuel consumption and air pollutant emissions, also allowing for steeper/noise-abatement climb paths
  • load alleviation to avoid aerodynamic loads exceeding given limits at critical conditions (gust and high-speed manoeuvre), thus optimising the wing structural design for weight saving
  • low airframe noise to reduce acoustic impact in approach flight configuration

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Figure 1 – GRA ITD, LNC domain: project logic

Relevant to mainstream technologies, several concepts and respective technical solutions have been investigated, including:

  • NLF wing to improve aerodynamic efficiency in cruise
  • Active control of wing movables for LC&A functions
  • Gapless HLD (droop nose, morphing flap), in addition to conventional solutions (Krueger, standard flap)
  • Low-noise solutions for HLD and landing gear

Major Demonstrators

LNC domain Demonstrators

The final step of the technologies maturation road map is relevant to the technologies demonstration in a realistic experimental environment, representative of the operational conditions expected in flight (TRL 5).

In order to accomplish this task, a number of demonstrations - either through wind tunnel tests or ground tests - have been planned. By taking into account the multi-disciplinary scenario of the technological fields investigated, in many cases different demonstrations were needed for a given technology to comply with requirements in terms of aerodynamics, aeroelasticity, aeroacoustics, structures, systems, and so on.

Synoptic tables give an overview of concerned demonstrations for 130-seat GTF A/C (Figure 2) and 90-seat TP A/C (Figure 3). Most of the demonstrations are taking place within the framework of projects under Calls for Proposals.

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Figure 2 – Synopsis of technologies demonstrations for 130-seat GTF Green Regional A/C

 

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Figure 3 – Synopsis of technologies demonstrations for 90-seat TP Green Regional A/C

 

  • Natural Laminar Flow Wing Wind Tunnel Demonstrator

Participants

Partners of Project ETRIOLLA (under CfP): IBK (Germany) – coord., FOI (Sweden), Revoind Industriale (Italy), University of Bristol (United Kingdom), Re Fraschini (Italy) - subcontractor

Objectives

Demonstration of NLF wing design at transonic cruise and of load control performance (increased aerodynamic efficiency) in high-speed off-design conditions

Features

Half-Wing 1:3 WT model (Figure 4), reproducing the wing's nominal flight shape at transonic cruise, equipped with load control devices (small flaps and split ailerons)

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Figure 4 – NLF Wing 1:3 WT model CAD geometry / sketch of load control devices

Tests

ONERA S1MA, Modane, France – November 2016

 

  • Gust Load Alleviation Strategy Wind Tunnel Demonstrator

Participants

Partners of Project GLAMOUR (under CfP ): Politecnico di Milano (Italy) – coord., IBK (Germany), Revoind Industriale (Italy), University of Bristol (United Kingdom).

Objectives

Demonstration of the viability of the Load Alleviation system (sensors, control laws, devices actuation) within a realistic environment under gust occurrence

Features

A/C aero-servo-elastic 1:6 WT half-model with:

  • flexible wing, made up of carbon fibre spar (Figure 5) and segmented aerodynamic shape, reproduced by stiffness scaling the full-size wing dynamic response to high-speed gust excitation loads
  • rigid fuselage and tail
  • accelerometers / alpha flow sensor
  • active movables (aileron and elevator)
  • control laws engineering models
  • Six-vane (air flow deflectors) gust generator system at proper scaled frequencies (Figure 6)

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Figure 5 – Wing spar Ground Vibration Tests

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Figure 6 – Scheme of WT model installation

Tests

  • Politecnico di Milano WT, Italy – August 2016

 

  • Gust Load Alleviation Control System Ground Demonstrator

Participants

LEONARDO company – Aircraft Division (formerly Alenia Aermacchi)

Objectives

Validation of the Load Alleviation system control chain (sensors, control laws, devices actuation) through a test rig inserted in a realistic HW/SW operational environment

Features

  • System / Equipment under Test:
  • Sensors (real and simulated)
  • Loads estimator
  • Control Laws (feedforward channel controlling aileron / feedback channel controlling elevator) implemented in a (flyable) Flight Control Computer
  • Aileron actuator

Main Components

  • Mechanical Test Bench (Figure 7) hosting electro-hydraulic aileron actuator and load actuator
  • Load system / Load control electronics to verify aileron actuator performance under simulated loads (Figure 8)
  • Test management and simulation system: gust perturbation, A/C dynamics, elevator actuation (Figure 8)

 

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Figure 7 – Mechanical test bench

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Figure 8 - Load racks and simulation racks

Tests

LEONARDO company – Aircraft Division, FCS Dept. lab., Turin, Italy, December 2015

Results

  • Load Alleviation control laws successfully validated through a representative Flight Control System
  • Large reduction at wing root of 1st peak of bending moment and torque with respect to Load Alleviation system inactive case.

 

  • Morphing Flap Ground Demonstrator

Participants:

University of Naples “Federico II”, Italy - Industrial Engineering Dept., Aerospace Division

Objectives

Demonstration of mechanical performance of an innovative trailing-edge flap architecture conceived to enable dual-morphing functions:

  • Mode #1: overall flap camber morphing in high-lift (flap deployed) configurations (take-off, approach, landing)

  • Mode #2: flap tip (30% chord) upward/downward deflection at high-speed as load control device (flap stowed)

Features

Full-scale (3.6m span) aluminium prototype (Figure 9) sized to the inner half-panel of the outboard (tapered/swept) flap of the aircraft, characterized by:

  • Smart Actuated Compliant Mechanism (SACM) driving articulated 4-block (finger-like) morphing ribs
  • Continuous spars (at 5% and 70% chord) mainly for carrying external loads
  • Multi-box structural layout, with longitudinal stiffening elements, elastically stable under bending and torsion
  • Segmented four-plate skin (not shown in figure)

 

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Figure 9 – Morphing Flap ground demonstrator

Tests

University of Naples ‘Federico II’, Italy - Industrial Engineering Dept., Aerospace Division lab., March 2016

Results

Flap architecture functionality in both morphing modes successfully verified through controlled relative motion of rib elements (videos available)

 

  • Wing Droop Nose Ground Demonstrator

Participants

Fraunhofer

Objectives

Demonstration of the mechanical performance of a gapless morphing leading-edge High-Lift Device based on a smart actuation/kinematic system

Features

Full-scale (3.0m span) mechanical prototype/ technology platform (Figure 10), sized to I/B region of a real device, characterised by:

  • Rotational-Lever Mechanism to transmit forces to the skin, connected to a shaft driven by an external actuator
  • Composite flexible skin
  • SMA patches to contribute to skin cambering
  • FOBG sensors for strain monitoring
  • CNT-based Ice Protection System
  • Synthetic Jets Actuators (on the rear fixed part)

 

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Figure 10 – Droop Nose ground demonstrator in the climate WT

Tests

  • Mechanical tests: to verify the actuation/kinematic system ability to properly deform the skin and the correct functioning of all components (Fraunhofer IBP lab., Darmstadt, Germany – September 2014)
  • Climatic WT tests: to verify the mechanism under representative aerodynamic loads and simulated operational (raining/ icing) flow conditions (Mahle-Behr WT, Stuttgart, Germany – October 2014)

Results

Successful demo of the Droop Nose mechanism and of relevant integrated technologies, through a prototype representative of a segment of a real device (video available)

 

  • Wing Droop Nose Wind Tunnel Demonstrator

Participants

Fraunhofer

​Objectives

Assessment of Droop Nose high-lift performance and noise emission

Features

Half-Wing 1:6 WT model (Figure 11), reproducing the wing clean geometry and the wing high-lift configurations (with trailing edge flap, with/without drooped nose)

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Figure 11 – Wing Droop Nose 1:6 WT model

Tests

Automotive WT, Germany, November 2015

Results

  • Successful demo of Droop Nose aerodynamic performance in a representative environment (model scale, flow speed), showing significant increment in aSTALL and in CLmax with respect to wing configurations with trailing edge flap only
  • Good correlation with results of CFD analyses on the WT model configurations at test conditions (Mach, Reynolds), thus validating numerical predictions of Droop Nose high-lift performance at full-scale
  • Acoustic test data (still under evaluation) allowed to detect different noise sources

 

  • 130-seat Geared Turbo Fan A/C Wind Tunnel Demonstrator

Participants

Partners of Projects ESICAPIA/EASIER (under CfP): IBK (Germany) – coord., Revoind Industriale (Italy), RUAG (Switzerland), Univ. of Bristol (United Kingdom), University of Roma Tre (Italy), Eurotech (Italy) – subcontractor

Objectives

Demonstration of the A/C aerodynamic (high-lift and Stability & Control) and low-speed performances

Features

Complete A/C 1:7 powered WT model (Figure 12), equipped with high-lift devices (Krueger, flap), control surfaces (ailerons, spoilers, elevator, rudder), nacelles / engines simulators and simplified landing gear

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Figure 12 – GTF A/C 1:7 WT model CAD geometry

Tests

RUAG LWTE, Switzerland, August – September 2016

  • 90-seat Turbo Prop A/C Wind Tunnel Demonstrator

Participants

Partners of Projects LOSITA/WITTINESS (under CfP): IBK (Germany) – coord., Revoind Industriale (Italy), RUAG (Switzerland), University of Roma Tre (Italy), Eurotech (Italy) – subcontractor

Objectives

Demonstration of the A/C aerodynamic (high-lift and Stability & Control) and low-speed performances

Features

Complete A/C 1:6.5 powered WT model (Figure 13), equipped with trailing edge flap, control surfaces (ailerons, spoilers, elevator, rudder), nacelles / propellers / engines simulators and simplified landing gear.

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Figure 13 – TP A/C 1:6.5 WT model CAD geometry

Tests

RUAG LWTE, Switzerland, September 2016

  • Low-Noise Main Landing Gear Wind Tunnel Demonstrator #1

Participants

Partners of Project ALLEGRA (under CfP): TCD (Ireland) – coord., Eurotech (Italy), KTH (Sweden), Magnaghi (Italy), Pininfarina (Italy), Teknosud (Italy)
 

Features

1:2 WT model (Figure 14) representative of the whole (L/R sides) of the MLG installed architecture (gear, bay, doors, part of fuselage) equipped with several low-noise devices (strut fairings/ meshes, wheel hubcaps, bay sound-absorber panels)

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Figure 14 – MLG 1:2 WT model

Tests

Open-jet WT, Turin, Italy, October 2014

Results

  • The best low-noise device resulted from the main strut mesh, providing significant noise reduction overall across the frequency spectrum at different noise emission angles
  • The tests allowed for successful assessment of MLG noise in far field, of noise sources location, and of noise-reduction technologies on a realistic model at half-scale

 

  • Low-Noise Main Landing Gear Wind Tunnel Demonstrator #2

Participants

Partners of Project ARTIC (under CfP): TCD (Ireland) - coord., INASCO (Greece), NLR (The Netherlands). 

Objectives

Full-scale demonstration of MLG final low-noise configuration

Features

1:1 WT model (Figure 15) representative of the whole (L/R sides) of the MLG installed architecture (gear, bay, doors, part of fuselage) equipped with low-noise devices finally chosen (strut mesh/ wheel axle fairing and wheel hubcaps)

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Figure 15 – MLG 1:1 WT model: details of CAD geometry and of manufactured parts

Tests

DNW-LLF, Marknesse, The Netherlands, end 2016 / early 2017 (tbd)

 

  • Low-Noise Nose Landing Gear Wind Tunnel Demonstrator

Participants

Partners of Project ALLEGRA (under CfP): TCD (Ireland) – coord., Eurotech (Italy), KTH (Sweden), Magnaghi (Italy), Pininfarina (Italy), Teknosud (Italy)

Objectives

Full-scale demonstration of down-selected NLG low-noise devices

Features

1:1 WT model (Figure 16) representative of the NLG installed architecture (gear, bay, doors, part of fuselage) equipped with several low-noise devices (doors ramp-type spoiler, strut/ wheel axle fairings, wheels windshield, wheel hubcaps)

 

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Figure 16 – NLG 1:1 WT Model

Tests

Pininfarina open-jet WT,Turin, Italy, October 2014

Results

  • The best device result came from a ramp-type spoiler, providing strong noise reduction around 200Hz, corresponding to the cavity tone, and also a significant reduction overall in the frequency spectrum across the entire noise directivity range.
  • The tests allowed for a successful assessment of NLG noise in far field, of noise sources location, and of noise-reduction technologies on a realistic model at full-scale.
GRA3: All Electric Aircraft (AEA) domain

Overview

GRA3: All Electric Aircraft (AEA) domain

The AEA domain has been addressed to demonstrate the feasibility of on-board Systems using new technologies and architectures, applicable to Regional All Electric Aircraft - a new concept of aircraft studied due to the potential benefits in terms of greater engine efficiency, better power distribution, and consequent fuel consumption savings.

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Figure 1 – Main on-board systems affected by the AEA Concept

Figure 1 depicts the main aircraft systems affected by the All Electric Aircraft approach, which essentially removes the engine-driven hydraulic pumps and the air off-takes (bleed-less engine).

 

The main objectives of the project have been:

  • To define the requirements and to study on-board system architectures applicable to future all-electric regional aircraft.
  • To consider advanced on-board systems technologies in terms of efficient use of energy.
  • To develop, assess and validate innovative electric power management solutions.
  • To bring selected energy management technologies and solutions to in-flight demonstration.

 

In accordance with the project objectives, the major activities have been focused around the development and validation of innovative technologies and architectures relevant for the feasibility demonstration of selected advanced on-board systems for AEA, as per table 1:

 

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Table 1 – Innovative technologies for the AEA on-board systems studied in the AEA domain

 

The development of the innovative technologies for E-ECS and A-EPGDS have seen a significant contribution by System/Equipment Manufacturers, such as Liebherr TLS and Thales ES, operating in synergy within the framework of Clean Sky's System for Green Operation (SGO) ITD.

 

Major Demonstrators

AEA Technologies Demonstrators

A relevant step in the technology maturation road map is the technology demonstration in a realistic experimental environment, representative of the operational conditions expected in flight (i.e.: Technology Readiness Level = 5, TRL5).

In order to accomplish this task, a number of demonstrations, both through ground tests and flight tests, have been planned.

Some demonstrations take place in the framework of projects under Calls for Proposals.

The A-EPGDS technologies and most of the electrical integration ground demonstration equipment have been tested using the Electrical Test Bench (ETB), part of the Copper Bird developed by Safran Electrical & Power operating in synergy within the framework of Clean Sky's Eco-Design for System (EDS) ITD.

 

  • Technologies for E-ECS Aircraft Demonstrator

Participants

Liebherr TLS, ATR, LEONARDO company – Aircraft Division (formerly Alenia Aermacchi), Thales ES

Objectives

  • E-ECS Power Electronic and Moto-Turbo Compressor operating demonstration in relevant environment.
  • E-ECS on-ground and in flight demonstration validating the E-ECS integration and installation (Figures 2).
  • Evaluation of the E-ECS behavior (no performance target, since not fully representative for a regional A/C configuration).

Main Features

  • ATR 72 Demonstrator Aircraft (by ATR)
  • One Electric Pack (by Liebherr TLS) replacing the existing right pneumatic pack
  • One E-ECS Power Rack (by Liebherr TLS)
  • New aircraft 115 VAC Generation (By Thales ES) for E-ECS Power Supply 

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Figure 2 - E-ECS Pack and E-ECS Power Rack on ATR 72 Demo Aircraft

Tests

  • ATR, St. Martin, France

Four (4) A/C Ground and two (2) Flight Tests in the Period: 1st February – 7th March 2016.

Results

  • Successful demo of E-ECS Pack on ground and in flight.

 

  • ​Technologies for A-EPGDS: 270 HVDC Network and
    Electrical Power Center (EPC) for Electrical Energy Management (E-EM) Aircraft Demonstrator

Participants

  • Thales Electrical System, LEONARDO company – Aircraft Division (formerly Alenia Aermacchi), ATR, Liebherr TLS
  • Partners of Projects EPOCAL (Under GRA CfPs): Seconda Università di Napoli (SUNAP - Italy) - coord., Aeromech srl (Italy)
  • Partner of Project SREL (under GRA CfP) – Dana Srl (Italy)

Objectives

  • To test an Innovative Electrical Power Centre and validate the embedded Electrical Energy Management (E-EM) strategy applied for an Intelligent Power Supply and Distribution Management to the A/C Electrical Loads.
  • Verification of 270 High Voltage DC for the Electrical Power Distribution (through TRUs).

Features

  • ATR 72 Demonstrator Aircraft installing (Figure 3):
  • Electrical Power Center (EPC) (by Aeromech/SUNAP)
  • Electrical Power Rack (by Leonardo) including Two TRUs (by Thale ES)
  • Simulated Resistive Electrical Load (by DANA)

In addition to the E-ECS (by Liebherr TLS) used as “power sink”.

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Figure 3 - 270 HVDC Network & E-PC (E-EM) on ATR Demo Aircraft

Electrical Rack (including TRUs)
Electrical Power Center (EPC)​
Resistive electrical Load (SREL)

Tests

  • ATR, St. Martin, France, 7th March 2016

Results

  • Successful demonstration of the 270 HVDC Channel and of the Innovative Electrical Power Centre and Energy Management (E-EM) logics. Data assessment in progress.

 

  • Technologies for Electromechanical Actuation Ground Demonstrator

Participants

  • LEONARDO company – Aircraft Division (formerly Alenia Aermacchi)
  • Partners of Projects ARMLIGT and FLIGHT EMA (under CfPs): CESA (Spain), Tecnalia (Spain) MDU (Spain)

Objectives

  • To test and validate the performance of a qualified Electro-mechanical Actuator and associated Electronic Control Unit (ECU) for extension/retraction of landing Gear (ARMLIGHT project).
  • To test and validate the performance of a qualified Electro-mechanical Actuator and associated Electronic Control Unit (ECU) for FCS Rudder surface actuation (FLIGHT EMA Project).

Features

  • EMA FCS Ground Test Bench (Figure 4)
  • EMA LGS Ground Test Bench (Figure 5)

Note: two EMAs In-Flight Test Benches have also been manufactured for EMAs/ECUs Electrical integration test In-Flight (Figure 6).

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Figure 4 – EMA FCS On-Ground Test Bench

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Figure 5 – EMA LGS On-Ground Test Bench

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Figure 6 – EMA LGS On-Ground Test Bench tecture-ECS Pack installed on ATR 72 Demo Aircraft

Tests

  • Qualification and Performance Tests: Tecnalia – San Sebastian, Spain
  • Electrical Integration tests:
    • ETB Copper Bird - SAFRAN Electrical & Power, Colombes, France, March – June 2016
    • ATR, St. Martin, France, 7th April 2016

 

  • Technologies for A-EPGDS Ground Demonstrator

Participants

  • Thales Electrical System, Safran Electrical & Power, LEONARDO company – Aircraft Division (formerly Alenia Aermacchi)
  • Partners of Projects I-PRIMES (under EDS CfP): Seconda Università di Napoli (Italy) - coord., Aeromech srl(Italy)

 

Objectives

  • To test the A-EPGDS innovative technologies as integrated in the new conceptual electrical architecture for a Future Green Regional All-Electric aircraft demonstrating the achievement of more efficient power generation, conversion and distribution subsystems.
  • To test an Innovative Electrical Power Center and validate the embedded Electrical Energy Management (E-EM) strategy applied for an Intelligent Power Supply and Distribution Management to the aircraft Electrical Loads.

​Features

  • Copper Bird Electrical Test Bench (ETB) (Figure 4) integrating advanced EPGDS Equipment and Technologies (Figure 7)

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Figure 7 - ETB Regional A/C Configuration – EPGDS Architecture-ECS Pack installed on ATR 72 Demo Aircraft

 

Tests

  • SAFRAN Electrical & Power, Colombes, France

Several tests performed in the period: July 2014 – June 2016

 

Results

  • Successful demo of A-EPGDS on Ground.
GRA4: Mission and Trajectory (MTM) domain

Overview

GRA4: Mission and Trajectory (MTM) domain

The aim of Mission and Trajectory Management (MTM) was to study, in coordination with the SGO ITD, avionics solutions enabling the aircraft to reduce its environmental impact.

In particular the following green functions (Fig. 1), implemented in Thales Avionics Flight Management System (FMS), were developed:

 

  • Green Cost Index (GCI): Optimum cruise speed
  • Optimum Flight Level (OFL): Optimum cruise altitude
  • Continuous Descent Approach (CDA): Optimum descent path

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Figure 1 – GRA ITD, MTM domain: FMS functions

Participants

Finmeccanica Aircraft Division (Leader); Thales Avionics, Cira+ cluster (i.e. Cira, Elsis), Airgreen cluster (i.e. University of Bologna/Forlì) as Associates.

 

Demonstrations

MTM Domain Demonstrations

The assessment was performed thanks to a synergy between the GRA Flight Simulator and GRASM:

  • GRASM was used to perform environmental benefits evaluation derived from the adoption of green FMS functions.

  • Flight Simulator, in which the Thales FMS SW prototype is integrated, was used for the Operational Validation.

 

  • Environmental benefits evaluation

In order to perform the environmental assessment, typical TP 90 missions are provided as input to GRASM (Fig. 2). In order to isolate MTM benefits the same aircraft configuration (Green TP90) was considered for both reference and green trajectories (Fig. 3), in particular:

  • 300 NM reference trajectories
  • 300 NM green trajectories à implementing MTM optimisation, trajectory data - e.g. cruise altitude, speed - have been calculated offline with green FMS.

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Figure 2 – GRA ITD, MTM domain: GRASM architecture

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Figure 3 – GRA ITD, MTM domain: assessment logics

 

The objective is to verify the benefits with reference to the initial Clean Sky MTM targets:

  •  COreduction 2 / 4 %
  •  NOX reduction 2 / 4 %
  •  Noise reduction 1 / 2 EPNdB

 

The global assessment was performed according to the following baseline scenario (Table 1) where most operational parameters (e.g. mission range, wind) are fixed.

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Table 1 – GRA ITD, MTM domain: environmental assessment scenario

According to the baseline scenario, the global MTM environmental benefits were in line with initial targets.

 

In addition to the above, in the MTM final report, an additional analysis was included in order to evaluate the impact of the following operational parameters on CO2 benefits:

  • Airline operations (i.e. mission length)
  • Meteo conditions (i.e. wind profile)
  • ATM constraints:
    • ATC altitude constraint during cruise
    • ATC time constraints during cruise
    • ATC altitude constraint during descent
  • Emission costs

 

  • Operational Validation

The Operational Validation was performed on a Flight Simulator (Fig. 4), in which the Thales FMS SW prototype was integrated. Flight crew flew a complete mission (Roma Fiumicino – Milano Linate) with all new MTM features (Fig. 5).

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Figure 4 – GRA ITD, MTM domain: Flight Simulator

 

The Operational Validation performed by means of the GRA Flight Simulator analysed the three FMS functions (i.e. GCI, OFL, CDA), considering also the new avionics features, integrated in the simulator, enabling the FMS function themselves:

  • Auto-throttle for speed management of GCI and CDA
  • Autopilot VNAV mode for CDA vertical guidance
  • Vertical display on MFD for CDA situational awareness

 

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Figure 5 – GRA ITD, MTM domain: Operational Validation scenario

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Table 2 – GRA ITD, MTM domain: environmental assessment scenario

The validation activity highlights satisfactory behaviour of the new functions, which, together with new avionic enablers, do not increase the pilot’s workload and assure proper situational awareness.

GRA5: New Configuration (NC) domain

Overview

GRA5: New Configuration (NC) domain

The main scope of the New Configuration (NC) Domain is to include all technologies studied inside the Green Regional Aircraft Joint Technology Initiative (JTI-GRA) in order to assess the benefits at complete aircraft level.

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Figure 1 – GRA ITD, NC domain: project logic

The NC receives all the results from the technological domains, with the main objective being to incorporate these results at complete aircraft level. 

 

Analysed Configurations

Conceptual Configurations

Within the NC, several conceptual aircraft have been analysed as follows:

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Two different seat-capacity classes have been analysed – at 90 and 130 seats.

For the first one, the turboprop engine has been considered, while for the second one both Open Rotor and turbofan (Geared turbofan and advanced turbofan) have been considered.

For both seat-capacity configurations the aircraft requirements have been derived, taking into account the results of year 2020 market forecast data.

The following table shows some of the Top Level Aircraft Requirements:

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Reference Concepts

All benefits are calculated in terms of

  • Fuel reduction
  • Pollutant reduction (in terms of CO2 and NOx)
  • Noise reduction

These benefits have been calculated with respect to two reference platforms, based on year 2000 technology with the same Top Level Aircraft Requirements of the JTI.

 

Technology assessment at A/C Level

Low Weight Domain

The results of this technology area will focus around reducing total aircraft structural weight.

 

Low Noise Domain

From this Domain all parameters coming from aerodynamic devices have been derived: cruise aerodynamic efficiency, weight reduction due to load control device, laminar concept, etc.

 

Mission Trajectory Management

The optimised trajectories have been included in mission profile, derived directly from the benefits of fuel and noise level reduction.

 

All Electric Aircraft

From this Domain all information in respect of the on-board systems architecture has been received. In detail, the following results have been used in the aircraft sizing process: equipment weight and integration, space allocation, and take-off power for engine sizing.

 

Aircraft Simulation Model

All technologies have been included at aircraft level by means of an aircraft simulation model (GRASM).

This code, using all aircraft databases in terms of aerodynamics, engine data, weight, etc., evaluates the performance for both reference and conceptual platforms calculating the noise and pollution.

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This code, provided to the Technology Evaluator, has been used to calculate the environmental impact on the single mission and at airport level.

 

 

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