Aerodynamic technologies for more effective,Aerodynamic ... · Safe control of hijacked aircraft Security …addresses the full scope of customer expectations. A Business Troublemaker:

AeroDays 2011

Adel Abbas Geza Schrauf (Airbus, Flight Physics)( g y )

Eusebio Valero (UPM)

Aerodynamic technologies for more effective,Aerodynamic technologies for more effective, environmentally friendly air transport system

KATnet Strategy

AeroDays 2011 Madrid, 30th Mar- 01st Apr-2011

Why KATnet?

KATnetKATnet isis aa coordinatingcoordinating actionaction onon KeyKey AerodynamicAerodynamic TechnologiesTechnologiessupportingsupporting thethe ACAREACARE VisionVision 20202020,, andand inin particularparticular itsits StrategicStrategicResearchResearch AgendaAgenda..gg

The particular objetives are:

Identification of relevant technologiesIdentification of relevant technologies> Investigate their maturity Investigate their maturity> develop adequate implementation strategies for future aircraft

Multidisciplinary assessment of candidate technologiesMultidisciplinary assessment of candidate technologiesMultidisciplinary assessment of candidate technologiesMultidisciplinary assessment of candidate technologiesfor a virtual aircraft configuration

Dissemination ofDissemination of KATnetKATnet informationinformationDissemination of Dissemination of KATnetKATnet informationinformation> via the KATnet homepage and newsletters> intensified contact & involvement with the academic community

Madrid, AeroDays 2011 Page 2

KATnet Partners

2020 Vision and Target: ACARE

And Associated GoalsChallenges Air Transport Future Challenges

Reduced passenger chargesQuality and Affordability

p g gIncreased passenger choiceTransformed freight operationsReducedReduced timetime toto marketmarket byby 5050%%

ReductionReduction ofof COCO22 byby 5050%%

Safety

Environmentyy

Reduction of NOx by 80%ReduceReduce perceivedperceived externalexternal noisenoise byby 5050%%…

Reduction of accidents rate by 80%Safety

Efficiency of h Ai

Drastic reduction in human error and its consequences

3X capacity increase99% of flights within 15’ of scheduleLess than 15’ in airport before short flights

the Air Transport System

Airborne - zero hazard from hostile actionAirport - zero access by unauthorized persons or productsAir navigation - No misuse. Safe control of hijacked aircraft

Security

…addresses the full scope of customer expectations

A Business Troublemaker: Oil Price Soaring

Typical Brent Crude Oil Closing Price

Oil Price

Capital cost+53 % DOC Change

A world of challenge & opportunity

Insurance

4$/USgal

Fuel cost

Navigation fees

Landing fees

Cockpit crew

Engine maintenance

Airframe maintenance

Line maintenance

Navigation fees

2 5$/US l

Marginal drag improvement are becoming cost efficient

C i l

Capital cost

Fuel cost

maintenance

1.5$/USgal2.5$/USgal

Reduced fuel burn through :

Fuel costCapital cost

Insurance

C k it Line

Airframe maintenance

Engine maintenance

Airframe Landing feesCockpit crew

Insurance

Fuel cost

1 B l 42US l

g•Drag reduction•Weight reduction

Cockpit crewLanding fees

Navigation fees

Line maintenance

maintenanceEngine

maintenance

maintenanceLine

maintenance

Navigation fees

+21 % DOC Change

1 Barrel = 42US gal

R&T - Creating Partnerships That Matter

Reduction of CO2 by 50%Objectives for 2020

Aircraft ManufacturersAircraft Manufacturers

Reduce external noise by 50%

E i M f t

?

Engine Manufacturers?

Air Traffic Management

?

Engine Technologies

• Counter-Rotating Open Rotor concept.EU-NACRE has demonstrated substantial i i ffi i (20%) f l b d tigains in efficiency (20%), fuel burn reduction

(23%) and MTOW (8%) with a comparable turbofan power plant.

Noise radiation and aeroelastic vibration problems must be addresed.

•• Two major areas of researchTwo major areas of researchjj••GTF GTF ••CROR CROR –– DREAM project led by DREAM project led by RollsRolls--RoycRoyce


Integrated Aerodynamic Design Standard @ 2008

T i l D B kd i C i Fli htTypical Drag Breakdown in Cruise Flight

90%100%

Trim

60%70%80%

l Dra

g Wave

Nacelle Interference

30%40%50%

of T

otal Other Interference

Parasitic

V t

0%10%20%

%

% Vortex

Profile

0%

Current Multidisciplinary Design Process for Whole Aircraft Configuration involves:-(1) Design to agreed Target Loading ie Vortex Drag traded against weight from the outset(2) Zero Interference Drag on Wing due to nacelle, flap support fairings, and wing tip devices

(3) Wing Wave Drag less than 1% with all other components attached

Identify Opportunities

• From the previous analysis both Vi d lift i d d d thViscous and lift-induced drag are the largest components of total drag for a typical transport A/C.

• Advances in materials, structures and aerodynamics currently enable significant lift-induced drag reduction.

Maximize effective span extension, Aspect Ratio (considering airport constraints) using composites in primary wing structure.Incorporate wing-tip devices.

• Viscous drag currently is area with largest potential for drag reduction.


largest potential for drag reduction.

Aircraft Configuration Technologies I

Highly Optimized Aerodynamics DesignWi l tWingletsFully 3D Integrated Wing / Powerplant / Fuselage Aerodynamics Design

Wing Tip Optimization PowerplantOp a o Powerplant

IntegrationWing Tip Optimization


Aircraft Configuration Technologies II

• High aspect ratio, joined-wing or more general non planar wing concepts.

A theoretical induced drag reduction up to 40%A theoretical induced drag reduction up to 40%. Several non-aerodynamics issues must be studied

including effects on stability and control, characteristics of wake vortices or structural implicationsimplications.


Aircraft Configuration Technologies III

• Forward swept wings (FSW)• Forward swept wings (FSW).FSW presents a lower LE and higher TE sweep,

this allows larger areas of NLF and less wave drag.But it can strengthen TE separation problems atBut, it can strengthen TE separation problems at

inner wing and has unfavorable gust behavior

• Blended wing body aircraft (BWB).Preliminary results showed remarkable

performance improvements of the BWB over conventional aircrafts, including a 15% reduction in takeoff weight and a 27% reduction in fuel burn gper seat.

Innovative concept as boundary layer ingestion or distributed propulsion can also be implemented.

S


Structural and stability issues are still open.

Viscous Drag and other Opportunities

•• Control Technology Targets:Control Technology Targets:

Friction drag Friction drag reduction employing “Flow Control” technologies:– Laminar flow technology : either NLF or HLF– Active suppression for surface turbulence drag

Flow separation Flow separation control technologies:– High speed flow separation control ( wave drag and shock control active/passive)shock control- active/passive)– Buffet control– Low speed flow separation control (control surface efficiency), including

moveable-less– Wing loads control for loads control– Undercarriage flow separation control , noise

Loads Control Loads Control technologies for weight reduction through loads alleviation:– Loads control strategies (MLA and GLA)

F ll b fit l b hi d if A/C i d i d i ht f th t tFull benefit can only be achieved if A/C is designed right from the start including these technologies – Receptive configurations

Viscous drag reduction: Laminar flow technology.

• Significant research experience & involvement in large EU programmes have been gained overthe past years. A net fuel saving of at least 10% could be expected by the laminarisation of thewing, the tail and nacelles.

••TwoTwo approachesapproaches maymay bebe envisagedenvisaged::

•Natural Laminar Flow –NLC- proposes to delaytransition through adopting a pressure philosophy topostpone transition.

H b id L i Fl HLFC i l d f• Hybrid Laminar Flow –HLFC- includes some formof additional control, e.g. via mass transpirationthrough the surface.

•The main issues for the HLFC concept suited for high swept wing are the drilling of suctionholes, the high quality suction surfaces and the reduced systems complexity.

Typical areas for potential viscous drag savings

•Progresses are needed in surface decontamination & anti-Icing systems for both NLF & HLFCconcept.•Laminar-flow technology readiness requires progress in structural design, manufacturing andproduction integration


production integration.

Laminar flow research - NLF

•The European research project TELFONA (Testing for Laminar Flow on New Aircraft) isdeveloping the tools needed to design and test a Natural Laminar Flow wing and to bebl t di t th i fli ht f t d d f NLF i ftable to predict the in-flight performance standard of an NLF aircraft.

• The calibration of transition tools for ETWwind tunnel.

Th i ti ti f th i t f i d• The investigation of the impact of noise andturbulence on transition location in 2D flow ina TsAGi wing tunnel.• The receptivity study of traveling CF vorticesp y y gto free stream turbulence and the receptivityof stationary CF vortices to roughness (KTHtest).

•The forward swept wing (FSW) configuration, studied in NACRE, offers manyadvantages regarding the NLF technology. The lower LE sweep for same 50% chordsweep yields to less CF instabilities and allows bigger NLF area to be obtained


sweep yields to less CF instabilities and allows bigger NLF area to be obtained.

Laminar flow research - Other Applications I

•On nacelle applications, the paneljunction causes the laminar to turbulenttransition. It is then important to movedownstream the junctions between thenose cowl lip and the external panelnose cowl lip and the external panel.

• Investigation of new anti-contamination devices (ACD) for leading g ( ) gedge relaminarization.

Without ACD: contamination occurs for ~ 250. ACD postponed up to ~ 380

Efficient for M = 1.7 and 2.7


Laminar flow research - Other Applications II

• Discrete Roughness Elements (DRE) extend the laminar region in cross flow transition dominated flows

Fli ht t t d CFD t ti d t d b th T A&M Fli htFlight tests and CFD computation conducted by the Texas A&M Flight Research Lab at ,increased laminar region from 30% to 60%of the chord.

30 Λ ,10 x 8 Re 6 °==

•Active Wave Control System considers the counter-wave actuation of a TS wave, yielding to substantialdelay of laminar-turbulent transitiondelay of laminar turbulent transition.

Successful application in the range of M = 0.2-0.5 has been carried out by TU Berlin with 90%reduction of TS wave amplitude. (at the errorsensor) in wind tunnel and by about 50% in flight


sensor) in wind tunnel and by about 50% in flight(with a glider),

High Speed PerformanceTurbulent Skin Friction Reduction

• Active control of large spanwise structures embedded in the boundary layer that decrease skin frictiony y

• Integrated system of sensors and actuators with distributed control and health monitoring

• Assessment of advantages of active systems compared with passive systems e.g. riblets, dimples


Riblets

• Technology descriptionRiblets are longitudinal groves in the aircraft’s surface. They act as longitudinal fences to impede the lateral movement of longitudinal vortices. This forces “sweep events” to occur prematurely and henceThis forces sweep events to occur prematurely and hence intensity of events reduced. They have to be sized with the viscous scale.Skin friction reductions up to 10% have been demonstrated in labs.


Dimples

• Dimples are small depressions in the surface that allow trapped regions of flow recirculation and thereby a pp g yreduction of skin friction.

• The length scale of the dimples appears to be similar to that of riblets i.e. within the laminar sub-layer of the boundary layer


Separation Control Technologies - Opportunities

• More efficient HL devices for increased Clmax• Increased pay load for given approach speed or • Reduced approach speed for given aircraft

• Increase aero performance of trailing edge high lift supports laminar wing designswing designs• Load benefits via e.g. span wise flow control adjustments•Noise benefits via reduction of flow unsteadinessNoise benefits via reduction of flow unsteadiness•Others interesting applications such as:

• Buffet control• Thrust vectoring• Vortices control • Flow control in highly curved duct inlets or nozzles


Passive flow control devices - VG

• VG are simply small aspect ratio airfoilsmounted normal to the lifting surfaces aheadof separation point to energize the boundarylayer and prevent separationlayer and prevent separation.

• Vortex Generator (VG) and Sub-boundary layer VG (SBVG), the latterbeing totally immersed into the boundarylayer are studiedlayer are studied.• Improved attached flows in Pylon-winginterference or internal flows S-ductengine air-intake configurations andb ff t t l h b t di d bbuffet control have been studied byOnera and KTH.• Achieving optimal design and obtainingthe ideal VG location is still not obvious.Position and height of the VG (efficiency,sweep, boundary layer sensitivity, dragpenalty, efficient numerical simulationunderway)


Active flow control devices - FVG

• Air-jet vortex generator produces strong discrete vortices with higher momentum cores. •Wind tunnel demonstration of shock boundary ylayer interaction, separation control in transonic regime by use of pneumatic VGs, actuator to control lift and drag on a NACA0012 Airfoil has been performed in EU-AVERTAVERT.

• Fluidic jets for thrust vectoring control, where the length and slope angle of the g gdivergent part of the nozzle, the location and angle of blowing is analyzed.

• Different parameters are involved and still need to be clarified.

Jet nozzle diameter. Th j t it h d k lThe jet pitch and skew angle. The velocity ratio (VR)

number (internal/free stream).


Flow Control by Suction/Blowing

High Lift Flow Control on infinite swept Model

Periodic flow control at fl l di dflap leading edge

ujet =20%ujet = 70%

Phase averaged hot wire tests

u 20% u 70%

Conclusion:


Conclusion:• active separation control on a high-lift configuration was tested successfully at

low speed and small scale

Enabling Technologies

• Development of reliable, high efficiency, low power and cheap to manufacture Micro-Electro-Mechanical Systems (MEMS)Micro-Electro-Mechanical Systems (MEMS)

Turbulent boundary layer drag reduction, flow separation at high and low speeds and active shock control.Distributed MEMS (sensors Network actuators) architectureDistributed MEMS (sensors, Network, actuators) architecture.Wireless connectivity.

• Other actuators : mass-less & high efficiency micro jet actuators/systems• Passive means for drag reduction and separation control (e g riblets vortex• Passive means for drag reduction and separation control (e.g. riblets, vortex

generators, shock bump). • Surface coating – anti-contamination.• Systems architectures for active/passive flow/loads control• Systems architectures for active/passive flow/loads control.• Transition detection systems.• Advanced methods such as LES/DNS (Large Eddy Simulation/Direct

Numerical Simulation) and CAA (Computational AeroAcoustics) to beNumerical Simulation) and CAA (Computational AeroAcoustics) to be deployed at representative flow conditions to understand how fluid mechanisms which are responsible for drag and noise can be controlled.

Is there anything else?

Of course!!!

Numerical and i t l t lexperimental tools.

Manufacturing and gcertification issues


Numerical tools for flow control

• Mean flow simulation with 3d Finite-Volume code ELAN• Modelling based on URANS and Detached-Eddy Simulation (DES)

Vorticity


Without control With control

Thank you! Any questions?


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Aerodynamic technologies for more effective,Aerodynamic ... · Safe control of hijacked aircraft Security …addresses the full scope of customer expectations. A Business Troublemaker: