Overview of CIRA participation in the Clean Sky GREEN ... · Greener Aeronautics Symposium – Glasgow - 3 November 2014 4 The G reen R egional A ircraft (GRA) ITD Regional market

Overview of CIRA participation in the Clean Sky

GREEN REGIONAL AIRCRAFT (GRA) ITD

Greener Aeronautics Symposium University of Glasgow - 3 November 2014

Raffaele Salvatore Donelli, PhD

Centro Italiano di Ricerca Aerospaziale

CSJU Seconded Project Officer

Greener Aeronautics Symposium – Glasgow - 3 November 2014 2

Forewords

Clean Sky Green Regional Aircraft ITD

GRA Domains

New Configuration

Low Weight Configuration

Low Noise Configuration

Partial review of CIRA contribution

Green Regional Aircraft ITD

Overall scenario of Technologies & Demonstrations


The GRA ITD in the Clean Sky JTI

Eco-design For Airframe and Systems

Vehicle ITD

Tra

nsvers

e I

TD

for

all

veh

icle

s

Smart Fixed-Wing

Aircraft

Green Regional

Aircraft Green

Rotorcraft

Clean Sky Technology Evaluator

Sustainable and

Green Engines

Systems for Green

Operations

Leaders: Airbus

& SAAB

Leaders: Eurocopter

& AgustaWestland Leaders: Alenia

& EADS CASA

Leaders: Dassault Aviation

& Fraunhofer Institute

Leaders: Rolls-Royce & Safran

Leaders: Liebherr

& Thales

ITD: Integrated Technology Demonstrator


The Green Regional Aircraft (GRA) ITD

Regional market is a large part of Air Transport System: today, in

the world, 45% of flights are operated with regional aircraft.

In 2020 the share is estimated to rise to around 50%.

Substantial contribution to the “Clean Sky” shall then come from

the Regional Air Transport

Improvement of the environmental impact deriving from the

operation of regional aircraft are expected mainly from weight, drag

and noise reduction technologies, as well as from the integration of

advanced technologies belonging to other domains.


GRA High Level Objectives

To demonstrate technologies for future regional aircraft aiming at reducing:

fuel consumption/pollution

external noise

Ecolonomic Life Cycle

ACARE Goals

(CO2 & NOx reduction)

Aircraft Design Area Aerodynamics Structures&Materials Propulsion Power Requirements

Aerodynamics Flight Procedures Propulsion

Materials Design Concepts Standards & Rules

Green Perfomance

External noise

pollution & fuel consumption

Life Cycle


GRA High Level Work Program

Achievements of environmental targets through:

advanced aerodynamics and low noise design (Low Noise Configuration domain)

advanced structures and materials (Low Weight Configuration domain)

all electric aircraft architectures (All Electric Aircraft domain)

advanced avionics architectures (Mission Trajectory Management domain)

integration of these technologies in advanced aircraft configurations

interfacing new power plants (New Configuration domain)

Integration of technical solutions from other technology platforms of the

Clean Sky (energy management and Mission & Trajectory management

for SGO, engines for SAGE, Eco Design) in the Demonstrators of the

Green Regional Aircraft, using a multi-disciplinary approach


E c o-D e s ign IT D

E D A

G RA 1

L ow W eigh t

C on f igu rationAle n ia

S F W A IT D

G RA 2

L ow N oise


E c o-D e s ign IT D

E D S

---------------------

S G O IT D

G RA 3

A ll E lec tr ical

A irc raf tAle n ia

S G O IT D

G RA 4

M iss ion & trajec tory

M an agem en tAle n ia

T E -----------

S A G E IT D

-----------------

S F W A IT D

G RA 5

N ew


G R A 0M an agem en t

A le nia + E A D S C A S A

Interface btw GRA and other ITDs

GRA ITD Top-level WBS & Links

5 Technological Domains


Low Weight configurationsA/C Integration & technologies from

other ITD’s

GRA ITD

Requirements

Technologies

Studies and solutions

Ground Demonstration

Flight Demonstration

Low Noise configurations

Requirements

Technologies


Wind tunnel testing

Iron bird


New Configurations

All Electric Aircraft

Mission & Trajectory Mngnt

Low Weight configurationsA/C Integration & technologies from

other ITD’s

GRA ITD

Requirements

Technologies


Ground Demonstration


Low Noise configurations

Requirements

Technologies


Wind tunnel testing

Iron bird


New Configurations

All Electric Aircraft

Mission & Trajectory Mngnt

GRA ITD WBS & CIRA Contribution


New Configuration (NC) Domain

New Configuration Domain has the objective to design greener aircraft

configurations based on the implementation of several breakthrough

technologies to improve the aircraft performance in terms of both fuel

consumption and noise emission. At least 5 areas, such as aerodynamics,

structures and materials,

control systems, and

propulsion technology are

subject to improvements Boundary Layer Control

Composite

Structure

Propulsion Technology

Active Controls

New Airfoil Concepts


New Configuration (NC) Domain

LOW SPEED TURBOPROP

ADVANCED TURBOFAN

PUSHER OPEN ROTOR

GEARED TURBO FAN


The design of a green aircraft is strongly affected by the accuracy

of the data and by their reliability. At this end, three different stages have

been foreseen before arriving to the final aircraft design.

Loop 1 Loop 2 Loop 3

•Technology Readiness Level (TRL)

TRL 2 TRL 4 TRL 5 TRL 1 TRL3

Literature or/and

Statistical data

Improvements estimated by

3D CFD

Basic Wind Tunnel

by increasing the reliability data

Wind Tunnel T.

Flight Tests

NC Domain – Strategy Loops


NC Domain – Loop 3

Design of laminar GRA Aircraft

Loop 3

Aerodynamics

Structures

Systems

Propulsion

Natural Laminar flow design of the wing

• Polar (WT experiments – WTT2)

• Pitch Moment (experimental estimation)

High lift performance (Low WT tests – WTT4)

Composite Materials (2 Down selection)

• structural tests on large panels

• Weights

• Bench tests

Benefits coming from LC&A application (WTT2 tests)

• Bending moment estimation

• Load alleviation benefits

Electric System (ground Electrical Test Bench)

• Envisaged weight reduction

Engine performance

• Final data from engine manufacturer

Fu

el C

on

su

mp

tion

No

ise

Re

du

ctio

n

Weight reduction

L/D

Improvement

Design of laminar GRA Aircraft

Loop 3

Aerodynamics

Structures

Systems

Propulsion

Aerodynamics

Structures

Systems

Propulsion

Natural Laminar flow design of the wing

• Polar (WT experiments – WTT2)

• Pitch Moment (experimental estimation)

High lift performance (Low WT tests – WTT4)

Composite Materials (2 Down selection)

• structural tests on large panels

• Weights

• Bench tests

Benefits coming from LC&A application (WTT2 tests)

• Bending moment estimation

• Load alleviation benefits

Electric System (ground Electrical Test Bench)

• Envisaged weight reduction

Engine performance

• Final data from engine manufacturer

Fu

el C

on

su

mp

tion

No

ise

Re

du

ctio

n

Weight reduction

L/D

Improvement


LOW SPEED TURBOPROP ADVANCED TURBOFAN

GEARED TURBOFAN

Best configuration choice for WTT

More Electric Aircraft Systems (Trade-off activities)

Feasibility studies under Structural and Systems points of view Lo

op

3

Rear engine installation Under wing engine installation Under wing engine installation Rear & Under wing engine

installation

Lo

op

2

Engine data updating (AEA hypothesis)

All Electric Aircraft and More Electric Aircraft Systems architecture definition

Aerodynamic Improvement (Wing design and HLD studies)

New materials improvement & Preliminary Structural layout definition

PUSHER OPEN ROTOR

NC Domain – Aircraft Configurations


Tech

no

log

y R

ea

din

ess L

evel

(TR

L)

TRL 3

TRL 4

TRL 5

TRL 6

NLF Wing Design

Mach 0.78

WTT 5

GTF A/C architecture &

power plant integration

complete powered large-

scale model

Geared Turbo Fan

Configuration LOOP 2

130 pax Aircraft configuration

WTT Testing complete powered large-scale model

2010 2011 2012 2013 2014 2015 2016 2017

WTT 4

WTT 2

GTF Configuration LOOP 3

Transonic NLF Wing design

WT Testing GTF A/C half-model

NLF

Wing Design

Mach 0.74

TRL 7

Geared Turbo Fan Conf. – Technological Road Map


NC Domain – CIRA Contribution

Benefits Assessment, Demonstration Methodology & Strategy for GRA A/C

(90&130 pax) Configurations

CIRA has established the strategy for the validation & verification of the benefits at A/C

level resulting from the integration of the new technologies.

Green open rotor A/C

CIRA has computed the Aerodynamic database of the open rotor configuration in

cruise, take-off and landing conditions by means of 2D /3D analysis tools.

Giovanni Andreutti ([email protected])

Aeroacoustic analysis starting from the CFD data

Mattia Barbarino ([email protected])

GRASM

Contribution to GRASM implementation (Trajectories evaluation, Databases

implementation, Mission and Airport Level analysis for GTF configuration) in order to

supply the TE assessment

Pierluigi Iannelli ([email protected])

mailto:[email protected]


Low Weight Configuration (LWC) - Objective

Develop the most promising technologies to reduce the weight and

best fitting the requirements of the Green Regional Aircraft taking

into account requirements coming from other domains such as New

Configuration or Low Noise

Enabling Technologies

Structure-Embedded Sensors to continuously control accidental damage,

environment effects, and consequently in-service structural degradation.

Layer, Multilayer/multi-function architectures to decrease the negative

impact on weight deriving from ancillary functions requested to the structure

(lightning protection, grounding,…).

Nano-material technologies (nanomodified prepreg production, …).

Advanced metallic structure (fully laser welded integral structure, welded

applied to Titanium sheet, …).


LWC Domain - Technologies

WEIGHT REDUCTION

Noise Damping

Flame Smoke

and Toxicity

resistance Impact resistance

Structural property

Lightning strike Protection

Self-healing

Multifunctional Layer A multifunctional single layer is a

structure in which different

materials are integrated - in order

to assure several functions - in a

way that is impossible to identify

them as separate layers

A multifunctional multi-layer is a

structure in which different

materials are integrated, in order

to absolve several functions

Multifunctional Multilayer

Damping

Flame resistant

Conductive

WEIGHT REDUCTION

Environment barrier

Self-healing


Sensors: Fiber Optic Bragg Grating

(FOBG)

BRAGG

GRATING

FIBER OPTIC

TERMINATION

Cobonded J-spar with embedded

FOBG sensors

Carbon nanotube strengthened epoxy resin for increased compression and interlaminar shear strength in composites (fuselage and wing)

Nanomaterials

Nanotubes

Monitoring events occurring to

aircraft during its operation

through sensors embedded in

the structure for damage

detection, life management,

and repair and maintenance

actions

LWC Domain - Technologies


LWC Domain – Development Plan

JTI –GRA LWC Development

Research and Technologies acquisition

Requirement & Architectures

Technologies Development

Application Studies

Demonstrators

Yo Y3 Y7

First Down

Selection

Second Down

Selection

After the selection of the most interesting technologies, theoretical and esperimental investigations

have been carried out. Based on these results, only the most promising technologies were selected

for further and deeper analysis.

The enabling technologies have been selected by two down selections.

First Down Selection, at a given date, based on numerical studies and basic ground

testing on small/medium panels

Second Down Selection based on ground testing and large panels


1 - Fibre Optics - FOBG

2 - Fibre Optics - FOBR OBR

3 - Fibre Optics - FOBR DSS

4 - Acoustic Ultrasound – AU-BB

5 - Acoustic Ultrasound – EMI

6 - Lamb waves

7 - Guided waves

8 - AE-AU active and passive methods

9 - Wireless Sensors

10 - Prepreg with metallic wires interwoven

11 - Prepreg cocured with metallic mesh

12 - Prepreg with thermoplastic layer cocured with microwave

13 - Prepreg with damping layer

14 - Monolithic laminates with acoustic damping material inserted

15 - Sandwich with acoustic core

16 - Prepreg nanocharged

17 - Nanomaterial for electromagnetic protection

18 - Nano-modifed resin for liquid infusion

19 - Nano-materials for innovative ice protection systems

20 - Al – Li Laser welded

21 - Repair & Maintenance

Total: 21 Technologies

1 - Fibre Optics - FOBG

2 - Fibre Optics - FOBR OBR

4 - Acoustic Ultrasound – AU-BB

6 - Lamb waves

7 - Guided waves

8 - AE-AU active and passive methods

9 - Wireless Sensors

12 - Prepreg with thermoplastic layer cocured with microwave

13 - Prepreg with damping layer

14 - Monolithic laminates with acoustic damping material inserted

15 - Sandwich with acoustic core

17 - Nanomaterial for electromagnetic protection

18 - Nano-modified resin for liquid infusion

19 - Nano-materials for innovative ice protection systems

20 - Al – Li Laser welded

21 - Repair & Maintenance

22 new – Liquid Infusion

Total: 16 + 1 Technologies

2008 2009 2011 2010

TRL 3 Coupons tests TRL 4

1st Down

Selection 12/05/2011

1st Down Selection

LWC Domain – First Down Selection


Flight Demo

Concepts Studies

Full Scale

Ground Demo

Panel to be replaced

2008 2009 2011 2012 2013 2014 2010 2015

Technologies development: req’s, design, manufacturing, assembly & test

Objective: to demonstrate the applicability of advanced CFRP, metallic alloys & process and structural

health monitoring systems to achieve the expected structural weight reduction for Regional A/C

TRL 3 TRL 4 TRL 5 TRL 6

Specimens /

Coupons

Flat large

panels

Fuselage

Ground Demo

Cockpit

Ground Demo

Wing Box

Ground Demo

Coupons and large panels tests activities

LWC Domain – First Down Selection

1° Down Selection 2° Down Selection


Fibre Optics - FOBG - (tests on coupons sensorised with fibre optic sensors)

Prepreg with metallic wires interwoven (tests on Prepreg with metallic wires

interwoven coupons)

Prepreg nanocharged (tests on Nano-reinforced resins coupons)

Wing & Fuselage flat large panels design criteria

Report on NDI results on composite flat large panels in Pre-Preg.

Project under Call for Proposals: composite panels with nanofiller dispersed

in resin manufacturing and testing.

LWC Domain – CIRA Contribution

Stefania Cantoni (s.cantoni@cirait)

Umberto Mercurio ([email protected])

mailto:s.cantoni@cirait




Fibre Optics - FOBG - (tests on coupons sensorised with fibre optic sensors)

Testing of the composite panel with embedded FOBG

Design and realization of the test rig

Test execution

The gap between the frames and the lower

plates allows a displacement in compression

of 10 mm

•Durability Test

•Repeatability test

•Break Test


•SGB1L

•SGB1R

•FOBG

Panels configuration

2 optical fibers (identified with the letters

A and B) are embedded in each panel,

angled at 45° with the load axis

Each optical fiber has 3 Bragg gratings

2 strain gages are aligned with each

Bragg grating on the front side of the

panel

1 strain gage is aligned with each Bragg

grating on the back side of the panel

2 additional strain gages are placed at the

midline of the panel, aligned with the load

axis



Low Noise Configuration (LNC) Domain

Aknowledgements

Some of following slides are courtesy of

• Michele Averardo (Alenia Aermacchi) as Responsible for

Low Noise Configuration Domain of the GRA ITD

Many thanks also to the whole GRA Alenia Team


To meet the targets stated by

the Clean Sky JTI toward a

drastic reduction of the

environmental impact by future

civil air transport, the GRA ITD

LNC domain is addressed to

breakthrough technologies

as Advanced Aerodynamics,

Load Control & Alleviation

and Low Airframe Noise,

tailored to 130-seat & 90-seat

Green Regional Aircraft.

LNC Domain – Toward ACARE targets



Such technologies are aimed to:

Enhance aerodynamic efficiency in the whole flight envelope, so as to reduce fuel burnt /

air pollutant emissions

Prevent aerodynamic loading from exceeding given limits at critical (gust & manoeuvre)

conditions for wing structural weight saving

Reduce A/C acoustic impact in approach/ landing phases

To meet the targets stated by

the Clean Sky JTI toward a

drastic reduction of the

environmental impact by future

civil air transport, the GRA ITD

LNC domain is addressed to

breakthrough technologies

as Advanced Aerodynamics,


and Low Airframe Noise,

tailored to 130-seat & 90-seat

Green Regional Aircraft.


Main Technical Solutions investigated Mainstream Technologies

Wing Optimised

Aerodynamics

Load Control

Load Alleviation

High-Lift Devices

Low-Noise

Landing Gears

Natural Laminar Flow

To reduce skin friction drag

High Aspect Ratio Wing & Winglets

To reduce induced drag

Active control of wing movables

To optimise span load distribution (induced drag reduction) in

off-design conditions

To reduce wing bending and torsion from gust & manoeuvre loads

Wing Aeroelastic Tailoring

Passive reduction of bending moment

Conventional & Innovative Architectures

Krueger, Basic Flap, Morphing Flap, Droop Nose

Low-Noise concepts

Liners, Fences

Bay cavity acoustic treatments

Liners / Sound absorbers

Aerodynamic Fairings

Strut covers, wheel rim caps



LNC - Technologies Maturation Road Map

Today Achievements (TRL 4)

Technologies developed on a multi-disciplinary basis (aerodynamics, aeroacoustics,

structures, systems) through CFD/CAA/CSM methods and CAD/CAE modelling, validated

(when applicable) by 2D WT Tests and laboratory experiments on small mechanical

prototypes, and integrated at A/C concept level.


LNC - Technologies Maturation Road Map

Next Step (TRL 5)

Technologies demonstrations in a realistic experimental environment, through

large-scale WT models and full-scale mechanical prototypes.


LNC Domain – 130-seat Aircraft

The 130-seat Green Regional A/C (Mach 0.74) is

a rear-mounted twin-engines Geared Turbo Fan

configuration with Natural Laminar Flow Wing.

Conditions:

Mach = 0.74

Reynolds = 21.2 millions

Ref. Length = X m

Wing Area = X m2 (half model)

Lift coefficient (WB) = fixed

Wing Lift coefficient = fixed

Grid size ~ 7 millions cells

136 Blocks

Zonal approach:

Fuselage Euler flow (no viscous drag)

Wing RANS flow


Low Noise Configuration (LNC) - CIRA

Objectives: Minimize the total drag coefficient (target = L/D>18)

Maximize the transition position

Constraints: X1 < CL < X2

CM > X

Fuel tank volume

Design variables: Angle of attack [1°: 2°]

3 piecewise linear twist variables distributed along span, centered respectively on root, crank and tip sections

2 piecewise linear section shape variables

Requirements for CIRA Laminar Wing Design


CIRA Wing Design Procedure

MOGA optimizer (GAW)

Design Variables

Geo modeler (GEORUN)

Wing geometry Wing-body intersection

Domain modeler/Mesh generator (ENDOMO/ENGRID)

Flow solver (ZEN) BL analysis (BL3D)

BL stability (PARAB)

GRID

Objective/constraints

Domenico Quagliarella, Emiliano Iuliano, Raffaele S. Donelli


Flow solver (ZEN) +

BL analysis (BL3D)

N factor value

BL stability (PARAB)

Transition line

Feedback

(second order effect)

Using the database

method, the influence of N

factor variation on turbulent

to laminar flow transition

can be evaluated with little

computational effort

CIRA Wing Design Procedure J. Perraud, D. Arnal, G. Casalis, J. Archambaud, R. S. Donelli, “Automatic Transition

Prediction using Simplified Methods”, AIAA Journal, Vol. 47, No. 11, November 2009

[email protected]

[email protected]

[email protected]





CIRA – Optimized Wing-Body



Airfoil Geometries and pressure coefficient distributions along the span

E. Iuliano, D. Quagliarella, R.S. Donelli, I.S. El Din, D. Arnal, “Design of a Supersonic Natural Laminar

Flow Wing-Body”, JOURNAL OF AIRCRAFT Vol. 48, No. 4, July–August 2011, DOI:

10.2514/1.C031039

Ubaldo Cella, Domenico Quagliarella, Raffaele Donelli, Biagio Imperatore, Design and Test of the UW-5006

Transonic Natural-Laminar-Flow Wing, JOURNAL OF AIRCRAFT Vol. 47, No. 3, May–June 2010, DOI:

10.2514/1.40932


Global results @ Design point

CL = X

Wing pressure CD = 100 dc

Wing friction CD = 30 dc

Body friction CD ≈ 80 dc (estimated)

Total drag = 210 dc

L/D = 24.7

AOA = 1.2°

CM = X

Transition lines for Ncrit = 15 (conservative approach)



CIRA – Transition Prediction Methods

Bl Codes

BLQ3D

3C3D

Stability Codes

• Nolli

• Cosal

Raffaele S. Donelli

[email protected]

Donato de Rosa

[email protected]




Velocity field

3D FD compressible

boundary layer

Velocity, temperature

BL profiles

• Nolli

• Cosal

• Database method

3D Euler/RANS CFD

TS – CF – Envelope

N factor curves

eN method

N critical choice Transition position

Check for attachment

line instability, Poll criterion

245R

BL Integral quantities

d, d*, q, H

CIRA – Transition Prediction Algorithm


LNC Domain – High Lift Devices

Various HLD architectures were assessed accounting for aerodynamic performances and

acoustic impact (from 3D CFD/CAA analyses and 2D WT tests), as well as for feasibility and

complexity of the actuation system, through virtual (CAD/CAE) kinematics modelling and, in

some cases, preliminary mechanical tests. The first two were:

Double-slotted Flap by ALA - Two-element, Fowler-type

T/E device, as benchmark of other HLD configurations.

Single-slotted Flap by PAI - Single-element full-Fowler T/E

device, conceived as an alternative less-noise solution with

respect to the baseline double-slotted flap.

As typically found on laminar wings, poor high-lift performance

(CLmax, αSTALL) resulted from 3D CFD analyses with flap only

configurations, due to early (α≈7°) L/E flow separation. Therefore,

in order to meet A/C low-speed requirements (approach speed

and attitude at landing), combined L/E and T/E high-lift devices

had to be considered. In doing so, both conventional and

innovative low-noise solutions were also investigated.

FLOW

SEPARATION

3D CFD


LNC Domain – High Lift Devices

Several HLD concepts have been studied on a multi-disciplinary basis, accounting for

aerodynamic and acoustic performances, structural and system issues, etc.

The attention was mainly focused on

Lined Flap

Morphed Flap

Kruger Slat

High Lift Technologies providing higher aerodynamic performances

without/minimizing penalties in noise emissions.

High Lift Technologies having higher acoustic performances without penalties in

aerodynamic

Fences


The main differences between a standard flap and a

lined flap are the presence of a micro-perforation on

the external facing sheet and an additional

honeycomb layer inside the flap.

The cavities generated by the micro holes and the

honeycomb behave as Helmholtz resonators

resulting in a sound-absorbing effect.

A 1DoF liner consists of single layer sandwich

with a solid back-plate, a micro-perforated face-

sheet and a honeycomb core.

The concept can be extended to a 2DoF liner by

adding a second honeycomb core separated by

a porous septum

CIRA – Liner Flap – Design Concept

Mattia Barbarino & Damiano Casalino

[email protected]


A sensible noise reduction (∆OASPL ≈ 6dB) with

respect to the baseline flap was predicted by 2D

CFD/CAA analyses. Such a very promising result was

partially confirmed by 2D WT Tests.

CIRA – Liner Flap – 2D CFD/WT Testing

Antonello Marino [email protected] & Ignazio Dimino [email protected]

baseline flap

OASPL Contour Plot:

lined flap




Originally designed for the flap of the TP 90-seat A/C, this concept has been later

on tuned also to the flap of the GTF 130-seat A/C WT model (ESICAPIA).

CIRA – Liner Flap – 2D CFD/WT Testing

Antonello Marino [email protected] & Ignazio Dimino [email protected]

2D WTT have confirmed the effectiveness of this low-

noise design (red line) against the baseline flap

•SPLdB

•f (Hz)

Lined Flap

Baseline Flap

•2D WTT

ΔOASPL ≈ 2-4dB




CIRA – Krueger Flap – Design Concept

Krueger Slat by CIRA - L/E device designed to greatly

enhance, combined with T/E flap, the wing high-lift

performance, so as to meet A/C low-speed requirements,

still preserving laminar flow on the wing upper side.

Very good high-lift performances were predicted by 3D CFD analyses,

confirmed by 2D WT tests, showing the ability of this device to delay

wing stall up to large angles of attack (≈13 deg), with a consequent

significant CLmax increase (≈ 0.5) wrt other HLD configurations.

The original designs of Krueger and T/E single-slotted flap were tailored by

ALA to the final GTF 130-seat A/C aerodynamic model; relevant 3D CFD

analyses in landing configuration

confirmed previous results, so as

the A/C low-speed requirements were

fully met. This architecture is the basic HLD

geometry brought to the final WT demonstration

on the complete A/C powered model (ESICAPIA).

FLOW

SEPARATION

SKIN FRICTION

@ POST-STALL

• = 14°

3D CFD


CIRA – Krueger Flap – 3D optimization

Automatic 3D Krueger shape-modification/positioning Automatic 3D flap shape-modification/positioning & droop spoiler rotation

CFD Analysis of initial configuration (flap separation)

Minimized flap separation after some

steps of optimization

Parametric CFD mesh (4 Mcells)


CIRA – Krueger Flap – 2D WT Tests

Krueger Slat + Single-Slotted Flap

As expected, 2D WTT confirmed numerical

analysis. Large increase in CLmax (≈ 0.5)

wrt other HLD and delay of the wing stall to

high angles of attack (≈13°)

SPLdB

f (Hz)

Krueger + S-S flap

baseline S flap

From 2D WT tests the airframe noise

spectra result comparable,

neglecting the peak at high

frequency, to those of the baseline

HLD geometry

Noise Impact

Aerodynamic Impact


CIRA – Fences – Design Concept

Fence type C

Fence type B

Fence type A

Reduction of flap side-edge vortex intensity and shear stresses: Flap side-edge noise reduction


grid particular

GRID FEATURES NO FENCES WITH FENCES

CELLS NUMBER ~1.60e+07 ~2.20e+07

TYPOLOGY UNSTRUCTURED UNSTRUCTURED

vortical flow structure side edge particular

CIRA – Fence for Flap– CFD/CAA


grid particular

CIRA – Fence for Flap– CFD/CAA

Contour plots of the turbulent kinetic energy for 2D sections extracted from the aerodynamic field of both baseline and side-edge fence configurations.

baseline side-edge fence


CIRA – Fence for Flap– CAA Results

The slotted fence reduces the noise efficiently (6-8dB).

Though slightly high noise appears among the frequencies up to 50 Hz.

Downwards microphone, 270o, 500m


Single slotted flap

without fence (C70)

C7A C7C C7B

Fence A Fence B Fence C Reference

00

CIRA – Fence for Flap– 2D WT Tests


CIRA – Fence for Flap– 2D WT Tests


with FENCE

2D WTT - SPL

Noise reduction detected from 2D WTT; noise sources localization

revealed fence effectiveness in reducing flap tip vortex intensity.

Device applied to the GTF 130-seat A/C WT model (ESICAPIA).

w/o FENCE

CIRA – Fence for Flap– Conclusions


CIRA – Morphed Flap – Design Concept

SACM Flap by UniNA - Smart Actuated Compliant Mechanism architecture, made up of

articulated ribs structure, actuated by an electric motor, enabling dual-morphing capability:

DESA Flap by CIRA - Deeply Embedded Smart Actuators

architecture, constituted by elastic cells connected each other

in a serial way along the flap chord; SMA actuators

contraction causes the relative rotation of the rib components.

•Mode #1

•2D Prototype

The morphed shape (mode #1)

will be tested on the complete

A/C WT model

(ESICAPIA).

Mechanical demo will be performed on a 1:1 (3.6m span) prototype

sized to the half (inner part) of the outboard flap

Mode #1: adaptive flap

camber (T-Off / Landing)

Mode #2: load control

tab (flap stowed)

•2D Prototype

Morphing Flap: Novel wing T/E device conceived to match a given

“target shape”, as an aerodynamically optimised cambered flap.

Two architectures have been developed:


CIRA – Morphed Flap– Design Concept

Optimized morphed flap geometry by CFD

2,7

2,8

2,9

3

3,1

3,2

3,3

3,4

3,5

0 1 2 3 4 5 6 7 8alfa

cl

baseline

best

Mechanical Concept


A mechanical prototype of a full-

size segment of the outboard flap

has been manufactured

and …

successfully tested …

demonstrating the functionality

and ability of the morphing flap

structure to match the target

shape, while withstanding

simulated aerodynamic loads.

CIRA – Morphed Flap – Prototype


CIRA – Morphed Flap – Prototype


SPLdB

f (Hz)

S-S flap

Morphed flap

Morphed Flap

the difference in terms of airframe noise between

original single-slotted (blue curve) and morphed (red

curve) flap shapes is negligible

Noise Impact

Results of 2D WT tests Vs numerical show an increment

in CL max (≈ 0.4) wrt the original single-slotted flap.

Nevertheless, the high-lift requirements are not fully met

because of low stalling angle.

Aerodynamic Impact

Single

Slot

Morphed

CIRA – Morphed Flap – 2D WT Results


GRA – Nose & Main Landing Gear

Nose

Landing Gear

Main Landing Gear

The first step was the design of MLG and NLG

baseline architectures, jointly carried out by

ALA and MBD.


CIRA – Nose & Main Landing Gear

The second step was the development of low-noise concepts, by GRA

Members and Partners of projects ALLEGRA, CALAS & NOISETTE,

through numerical studies (empirical predictions and

CFD/CAA analyses) and basic WT Tests as well.

The feasibility of relevant solutions

was assessed by ALA & MBD and

some modifications were applied,

when necessary.

The NLG down-selected concepts were:

#N1 Spoiler

by NOISETTE

#N2 Wheels

wind-shield

by NOISETTE

#N3 Wheels

hub-caps

by FHG #N4

Perforated

fairings

by

ALLEGRA



Sea-level free-stream conditions

Vinf = 70 m/s

Pinf = 101.325 KPa

Tinf = 288 °K

Without bay door

With bay door

Francesco Capizzano ([email protected]

)




Francesco Capizzano ([email protected] )



CIRA – Landing Gear – Acoustic devices

3. Fairing design

The CIRA fairing proposal consists of two separated covers that has been designed by complying with the preliminary considerations, the bay geometrical constraints and by not interfering with LG kinematics.

Cover applied on the main leg and on the absorber

Reduce high frequency of the smaller parts;

Reduce interactions between main leg and absorber. Hole cap applied on the leg joint

Attenuate the hole cavity tone.

Rough estimation of the noise reduction

ΔdB = 10log(1-Sf) ~ 3dB

Sf (fairing surface/LG surface)

A draw-back of the classical fairing is that the high speed flow deflection

onto other components and fairing itself can introduce additional noise

sources.

Making the fairing porous can lead to an additional noise decrease.

Porosity of about 40% is the right trade-off


Bay and Door Liners

The device proposed consist of a set of absorber materials applied on the fuselage at the aim of dissipating acoustic energy (bay and door). Acoustic liners are sandwich materials that consist of honeycomb closed by two sheet layers. The facing-sheet is micro-perforated. Liners can be tailored to dissipate acoustic energy at certain frequencies by changing the liner manufacturing characteristics. The radiation characteristics of the liner is defined by the acoustic impedance Z.

2DoF 1DoF

Porous face sheet

Porous septum

Solid back-plateHoneycomb

h

h1

h2Porous face sheet

Porous septum


h

h1

h2

Porous face sheet

Porous septum


h

h1

h2Porous face sheet

Porous septum


h

h1

h2

Porous face sheet

Porous septum


h

h1

h2Porous face sheet

Porous septum


h

h1

h2

Porous face sheet

Porous septum


h

h1

h2Porous face sheet

Porous septum


h

h1

h2



CFD/CAA performed have showed that the

preliminary set of liner parameters for the

frequency of 300 Hz exhibits a modified SPL

directivity with an averaged SPL reduction of

1.3dB



GRA – Nose & Main Landing Gear

ALLEGRA Project

Tests on fulls cale Nose Landing Gear

Tests on Main Landing Gear – scale 1:2

Nose Landing Gear

In PininFarina WT


Other CIRA Activities

Synthetic Jet Simulation

Wind Tunnel Investigations on gap/step/roughness

effects on laminar flow

Drag Reduction (3D micro-riblets)

RANS solver development for open rotor simulations


LNC – Technologies & Demonstrations

WTT2 - NLF wind tunnel test investigation (high speed)

WTT8 - Gust Load Alleviation wind tunnel test investigation

GT1 - Load Alleviation Control System ground demo

GT2 - 3D Morphing Flap ground demo

GT3 - Droop Nose mechanics demo

WTT4 - A/C low-speed WT demo (aerodynamics performance)

WTT5 - A/C low-speed WT demo (aero-acoustic performance)

GRA 130-seat



Load Control (by ALA, CIRA, PoliTo)

Optimised span load distributions through

differential deflection of T/E devices (small

tabs, split ailerons) to enhance

aerodynamic efficiency

and to reduce static loads in

off-design conditions:

4 – 7% L/D increase

for 500nm mission.

Status:

CFD/CSM aero-elastic analyses - TRL 4

NLF Wing WT demo

ETRIOLLA (CfP) – In progress: presented today

TESTS (January 2015)

Laminar Flow extent in cruise (M 0.74) and off-design

conditions (M 0.7 – 0.8) at high Reynolds number

LC devices effectiveness in reducing induced drag

and bending moment in steady conditions at different

points (M, CL) of the flight envelope (climb, descent)

WIND TUNNEL

ONERA S1MA

WT MODEL

(Mechanical Design completed)

1:3 (5.7m span) half-Wing

flexible model reproducing

the full-size wing

deformation

(bending and

torsion) under

static loads

TEST SECTION #1

Ø ≈ 8 m, Mach ≈ 1.0

Target: TRL 5 Natural Laminar Flow Wing Optimised aerodynamic design (pressure

distribution), allowing extended laminar flow,

to reduce skin friction drag in cruise

(M 0.74, CL = 0.5): L/D (wing-body) ≈ 24.5

Status: CFD analyses – TRL 4

by ONERA, ALA



Load Control (by ALA, CIRA, PoliTo)

Optimised span load distributions through

differential deflection of T/E devices (small

tabs, split ailerons) to enhance

aerodynamic efficiency

and to reduce static loads in

off-design conditions:

4 – 7% L/D increase

for 500nm mission.

Status:

CFD/CSM aero-elastic analyses - TRL 4

NLF Wing WT demo

ETRIOLLA (CfP) – In progress: presented today

TESTS (January 2015)

Laminar Flow extent in cruise (M 0.74) and off-design

conditions (M 0.7 – 0.8) at high Reynolds number

LC devices effectiveness in reducing induced drag

and bending moment in steady conditions at different

points (M, CL) of the flight envelope (climb, descent)

WIND TUNNEL

ONERA S1MA

WT MODEL


1:3 (5.7m span) half-Wing

flexible model reproducing

the full-size wing

deformation

(bending and

torsion) under

static loads

TEST SECTION #1

Ø ≈ 8 m, Mach ≈ 1.0

Target: TRL 5 Natural Laminar Flow Wing Optimised aerodynamic design (pressure

distribution), allowing extended laminar flow,

to reduce skin friction drag in cruise

(M 0.74, CL = 0.5): L/D (wing-body) ≈ 24.5

Status: CFD analyses – TRL 4

by ONERA, CIRA, ALA



Gust Load Alleviation WT demo

GLAMOUR (CfP) - In progress

WIND TUNNEL

Politecnico of Milan

with gust generator system

at proper scaled frequencies

WT TEST SECTION

3×4 m, Mach ≈ 0.2

WT MODEL

1:6 (≈2.5m span) half-A/C

aero-servo-elastic model with:

flexible wing reproducing the

full-size wing dynamic behaviour

active gust LA devices

sensors & actuators

control laws engineering

model in the loop

TESTS (September 2015)

Viability of the LA system (control laws, devices and

sensors) coupled with the wing structural response

under gust excitation

Target: TRL 5

Reduction of dynamic loads from gust

encounter and manoeuvre by active

(feedforward + feedback) control of

ailerons and elevator,

e.g.: 25-chord gust

bending load first peak

reduced by 32%

Status: aero-servo-elastic

virtual A/C model coupling

aero-elastic and flight mechanics

models, sensors & actuators

models and control laws - TRL 4

Load Alleviation (ALA, CIRA, PoliTo)

Wing box torsional stiffness tailored to

spanwise lift distribution minimising wing

root bending moment (-8% at Nz = 2.5

MTOW) – passive LA - for wing

structural weight saving (13%)



JTI/GRA - GTF - ASSESSMENT OF FEED FORWARD & L1 CONTROL

Mx [Nm] at Wing Root (WS21) - ZFW - 25 Chords

3.43E+05

-1.14E+06

5.47E+05

-1.68E+06

-2.0E+06

-1.5E+06

-1.0E+06

-5.0E+05

0.0E+00

5.0E+05

1.0E+06

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

Time [s]

Lo

ad a

t W

ing

Ro

ot

Closed Loop - OPT21

Open Loop - OPT21

Load Alleviation (ALA, CIRA, PoliTo)

Wing box torsional stiffness tailored to

spanwise lift distribution minimising wing

root bending moment (-8% at Nz = 2.5

MTOW) – passive LA - for wing

structural weight saving (13%)

Reduction of dynamic loads from gust

encounter and manoeuvre by active

(feedforward + feedback) control of

ailerons and elevator,

e.g.: 25-chord gust

bending load first peak

reduced by 32%

Status: aero-servo-elastic

virtual A/C model coupling

aero-elastic and flight mechanics

models, sensors & actuators

models and control laws - TRL 4

Load Alleviation Control System ground demo

By ALA - Going to start

TEST RIG FEATURES & TESTS (October 2015)

Realistic system (sensors, real-time computer, control

laws and actuators) inserted in a simulated HW/SW

operational environment.

A key feature of the test rig will be the high dynamic

capabilities, in order to verify and validate the

performances of the LA control chain composed by

sensors, computing and actuation faster than

conventional A/C control systems.

Aim of the tests is to verify that

the transfer functions, from

sensors to computers and

to actuators, correspond to

the specified requirements

and so validate the simulations

performed to define the load control

and alleviation strategy.

AircraftAeroelastic

ModelAdaptive Law

Control Law

Low pass filter

State predictor

+-

Actuator Model

FeedForward AdaptiveController

L1 Adaptive Controller da

de

probe

de,effda,eff

Target: TRL 5



A/C low-speed WT demo

ESICAPIA (CfP) - In progress: presented today

EASIER (CfP) - Going to start

WIND TUNNEL RUAG LWTE

7×5 m TEST SECTION

M ≈ 0.2

TESTS (May – July 2015)

A/C aerodynamic S&C in takeoff and landing (M 0.20)

A/C acoustic impact and HLD low-noise solutions

WT MODEL

1:7

A/C powered model

with HLD and

control movables

Target: TRL 5

Aerodynamic and

Aero-acoustic

2D WT Tests

3D CFD Analyses

(Wing-Body-Tail-HLD)

M 0.2, Landing: CL max ≈ 2.7, αSTALL ≈ 14°

Morphed Flap: ∆CL max > 0.1

Status: TRL 4

High-Lift Devices #1

L/E Krueger Slat + T/E Flap (by CIRA,ALA)

Morphed Flap (see next slide)

Lined Flap (by CIRA)



3D Morphing Flap ground demo

By UniNA - In progress: presented today

TESTS (July 2015)

Ground Vibration Tests

Functionality tests to assess dual-morphing

capability with/without

simulated aerodynamic loads

Static Tests under limit loads

TEST ARTICLE


Morphing flap

tapered

(3.6m span)

full-scale

Mechanical

prototype

Target: TRL 5

Status: TRL 4


Morphing Flap – SACM (by UniNA)

Novel architecture, based on Smart Actuated

Compliant Mechanism, driving articulated finger-like

ribs, conceived to enable controlled wing camber,

both in takeoff/ landing as high-lift device (morphed

flap) and in cruise (flap stowed) as load control tab.

Tests on 2D mechanical

prototype (60×80 cm)

3D design sized to inner

half-part (3.6m span) of

the outboard flap



2nd design (2013-2014) – full-span Droop Nose

twisted: from 15° (18% span) to 0°(98% span)

constant 15°

deflection

Good results

from CFD


Droop Nose (by Fraunhofer)

L/E device with smart actuation based on external

actuator and rotating lever mechanism connected

to front stringers to transmit forces to the skin.

SMA patches on the lower surface contribute to

skin cambering and prevent from skin buckling.

1st design (2011-2012) - twisted Droop Nose:

from 10° I/B (18% span) to 0° O/B (67% span)

DISCARDED (HLD down-selection, D2.2.1-24)

due to bad high-lift performance from CFD.

Status: TRL 3

Droop Nose WT demo

By Fraunhofer - In progress: presented today

TESTS (Sept. 2014)

Aerodynamic assessment (high-lift performance

and stall onset), Mach ≈ 0.2

Aero-acoustic impact (noise sources

localization and overall Sound Pressure Level)

WT MODELS

≈1:6 half-wing modular WT model to test

high-lift configurations with T/E flap, with/

without droop nose

Half-wing (clean geometry) WT model at

same scale

Nozzle exit: 22 m2

Mach 0.19

Target: TRL 4

FACILITY

Automotive Weissach WT



2nd design (2013-2014) – full-span Droop Nose

twisted: from 15° (18% span) to 0°(98% span)

constant 15°

deflection

Good results

from CFD


Droop Nose (by Fraunhofer)

L/E device with smart actuation based on external

actuator and rotating lever mechanism connected

to front stringers to transmit forces to the skin.

SMA patches on the lower surface contribute to

skin cambering and prevent from skin buckling.

1st design (2011-2012) - twisted Droop Nose:

from 10° I/B (18% span) to 0° O/B (67% span)

DISCARDED (HLD down-selection, D2.2.1-24)

due to bad high-lift performance from CFD.

Status: TRL 3

Droop Nose ground demo

By Fraunhofer - In progress: presented today

TESTS (August 2014)

DN actuation performance (target deflection

w/o skin buckling or wavy deformation)

Icing protection system under droop nose

deflection and SJ actuators combined

functionality (with simulated icing conditions in

Wind Tunnel)

TEST ARTICLE (Mechanical Design completed)

Full-scale (3m span wing segment) carbon fibre

composite structure mechanical prototype, as a

technology platform integrating:

DN actuation system

and kinematics

CNT-based ice

protection system

Synthetic Jets

actuators

Target: TRL 4/5



LC&A System

Test Rig

Half A/C

aeroservo

elastic

1:7 WT model

GLAMOUR IN PROGRESS

ETRIOLLA IN PROGRESS

ESICAPIA IN PROGRESS

EASIER NEXT START

NLF Wing and

LC devices

high-speed

performances

WTT2

Gust Load

Alleviation

Strategy

WTT8

A/C low-speed

aerodynamic

performance

WTT4

A/C

acoustic

impact

WTT5

A/C powered

1:7 WT model

Half-Wing flexible

1:3 WT model

Droop Nose

aerodynamics


High-Lift Devices

NLF Wing

T E C H N O L O G I E S

1:6 WT Model

Droop Nose Wing Morphing Flap

Prototype

Droop Nose

Prototype

Gust Load

Alleviation

Control

System

GT1

Morphing

Flap

mechanics

GT2

Droop Nose

mechanics

GT3

D E M O N S T R A T O R S

D E M O N S T R A T I O N S



Thank You !

Documents

Overview of CIRA participation in the Clean Sky GREEN ... · Greener Aeronautics Symposium – Glasgow - 3 November 2014 4 The G reen R egional A ircraft (GRA) ITD Regional market