The Next Decade in Commercial - PDF Free Download

ROI 2009-0501-1167 The Next Decade in Commercial Aircraft Aerodynamics AB Boeing Perspective Mark Goldhammer Chief Aerodynamicist Boeing Commercial Airplanes Seattle, Washington, U.S.A. Aerodays 2011 Madrid, Spain 31 March 2011 BOEING is a trademark of Boeing Management Company. Copyright 2011 Boeing. All rights reserved.

Outline Historical look at aerodynamic configuration design at Boeing Driving factors for the future Aerodynamic levers for the next decade Aerodynamic product technologies Aerodynamic tools, processes and capabilities Airplane configurations Concluding remarks Copyright 2011 Boeing. All rights reserved. Aerodays 2011 2

The beginnings of the commercial jet age at Boeing Boeing 367-80 (circa 1954) Prototype for KC-135, B707 family Boeing s first low-swept-wing transport Configuration basis for the future: Wing-mounted pod engines Double-slotted Fowler flaps with LE Krueger flaps (B707) Boeing Stratocruiser (circa 1947) Straight wing Piston-powered propellers Fowler flaps Copyright 2011 Boeing. All rights reserved. Aerodays 2011 3

Wing-mounted pod engines became the configuration of choice B737 B747 B767 B777 Configuration evolution of the Boeing family Swept-wing, pod-mounted engines (2 or 4) Continually increasing aerodynamic technologies: CFD advances Airfoil/wing technology advances LE/TE high lift device advances Lessons learned from earlier products Higher Reynolds number wind tunnel testing Improved structural concepts More integrated wing/engine/pylon configurations Relaxed stability Load alleviation Multidisciplinary optimization B757 B787 Copyright 2011 Boeing. All rights reserved. Aerodays 2011 4

Other configurations B727 Wing-mounted pod engines were not always selected Aft-mount allows lower-to-the-ground configuration Perhaps more efficient with then-current technology Odd number of engines (3) Cabin noise and vibration challenges DC-9 DC-10 Copyright 2011 Boeing. All rights reserved. Aerodays 2011 5

Driving factors for future improvement Boeing commitment: Each new commercial airplane generation delivers at least 15% improvement in CO 2 emissions and fuel efficiency MORE FUEL Early jet airplanes HIGHER db Rela ative fuel us se 90% reduction in noise footprint 70% fuel improvement and reduced CO2 Noise db LESS FUEL LOWER db EVEN LESS New Generation jet airplanes 1950s 1990s 2010s Nose footprint based on 85 dba. EVEN LOWER Copyright 2011 Boeing. All rights reserved. Aerodays 2011 6

Further drag reduction is required for future efficiency improvement Core aircraft technologies Relative contributors to 787 efficiency improvement* Systems For current aircraft configurations, remaining areas for significant fuel-burn improvement in next 10-20 years are: Propulsion/propulsion integration Aerodynamic drag reduction Multi-disciplinary optimization Materials Engines Alternate aircraft configurations may allow further integrated improvements from core technologies Aerodynamics *Improvements are relative to 767-300ER Copyright 2011 Boeing. All rights reserved. Aerodays 2011 7

Aerodynamic levers Aerodynamic product technologies Airplane configurations Aerodynamic tools, processes, and capabilities (3) Airplane Configurations Copyright 2011 Boeing. All rights reserved. Aerodays 2011 8

Aerodynamic product technologies Laminar flow Turbulent skin friction reduction Advanced transonic wing concepts Active flow control Relaxed stability Advanced trailing edge device concepts Advanced variable camber concepts Integration of advanced engine concepts Multi-disciplinary optimization Advanced leading edge device concepts Copyright 2011 Boeing. All rights reserved. Aerodays 2011 10

Aerodynamic drag breakdown and reduction potential Drag breakdown (typical) Viscous and lift-induced drag are dominant drag components for subsonic aircraft in cruise Excrescence drag Wave drag Induced and trim drag Advances in materials, structures and aerodynamics enable significant lift-induced i d drag reduction Maximize effective span extension using composites Incorporate advanced d wing-tip devices Viscous drag Viscous drag is remaining area with largest potential for further drag reduction Copyright 2011 Boeing. All rights reserved. Aerodays 2011 11

Laminar flow drag reduction benefits and issues Natural Laminar Flow (NLF) and Hybrid Laminar Flow Control (HLFC) demonstrated in aerodynamic flight tests Transition flow physics generally understood Scale and sweep affect laminar-flow application (NLF vs. HLFC) Continuous progress in analysis and design methods Laminar flow reduces fuel burn, emissions and noise Benefit depends on scale of application Improved fuel burn allows smaller, lighter, quieter aircraft Estimated net potential fuel burn benefit for subsonic transports ~ 5 12 % Laminar flow application issues Manufacturing, certification, and operational requirements and impacts Drag benefit needs to be traded against increased weight, maintenance, cost, reliability, etc. Copyright 2011 Boeing. All rights reserved. Aerodays 2011 12

Some laminar flow activities 1985 1990 1995 2000 2005 757 NLF Flight test 757 HLFC Wing HLFC 787 flight test WT test NLF Nacelle SLFC Studies Steps WT Tests HLFC VLA studies Wing HLFC WT test F-16XL SLFC flight test Wind-Tunnel (WT) or flight test Product Development trade study Copyright 2011 Boeing. All rights reserved. Aerodays 2011 13

Nacelles shaped for natural laminar flow (NLF) Committed to 787 in 2005 Nacelle contours optimized with laminar transition location as additional design parameter Structural design and manufacturing methods tailored for NLF benefit Copyright 2011 Boeing. All rights reserved. Aerodays 2011 14

Turbulent flow drag reduction benefits and issues Riblet technology has been demonstrated to passively reduce local turbulent skin friction ~6 % Tunnel and flight tests with riblet films conducted Application constraints (shape, spacing, streamlining) are understood Riblet application i issues are not aerodynamic: Limited riblet shape and adhesive robustness over operational life (hydraulic liquids, hail, dirt and impact) Appearance relative to standard paint and livery Time required to install, maintain, remove and re-apply ` Copyright 2011 Boeing. All rights reserved. Aerodays 2011 15

Boeing drooped-spoiler flap Committed to 787 in 2005 767 Double/single slotted with Fowler motion 6-bar linkage 787 Single/single slotted Simple-hinged flap with drooping spoilers Fewer parts (reduced maintenance) Lower weight Smaller fairings Facilitates small flap adjustments in flight Copyright 2011 Boeing. All rights reserved. Aerodays 2011 16

Boeing trailing edge variable camber Committed to 787 in 2005 Trailing edge variable camber allows Load optimization Cruise drag optimization Aileron Outboard flap Flaperon Inboard flap In cruise, trailing edge elements are adjusted at regular intervals to minimize drag Simplified actuation system Small angle variations Up and down movements Copyright 2011 Boeing. All rights reserved. Aerodays 2011 17

Active Flow Control (AFC) Example: Application concept study with AFC augmented wing high lift system (Reference NASA CR-1999-209338) AFC High lift configuration with AFC actuators AFC Evaluating Active-Flow Control (AFC) actuator and integration concepts for simplified (lighter) systems s with similar performance as traditional t a mechanical ca high-lift tee elements e Robust, reliable and low-maintenance AFC actuation to be developed and demonstrated for commercial transport Key issues that affect application success for commercial aircraft are: Actuator capability, robustness and noise System power, complexity and cost Failure modes and redundancy da considerations o s Copyright 2011 Boeing. All rights reserved. Aerodays 2011 18

Aerodynamic tools, processes and capabilities Computational fluid dynamics Wind tunnel testing Flight testing CFD Aerodynamic design and analysis Wind tunnel Future aerodynamics engineers Flight testing Copyright 2011 Boeing. All rights reserved. Aerodays 2011 20

Computational Fluid Dynamics (CFD) Faster, more capable, and less costly computing hardware Faster and better algorithms Higher fidelity flow physics modeled Expanding simulations towards edges of flight envelope Integration with structural and systems modeling (MDO) Integration with wind tunnel and flight testing Copyright 2011 Boeing. All rights reserved. Aerodays 2011 21

The future for wind tunnels Wind tunnels will continue to play a significant role in commercial airplane aerodynamic development: Design verification Database collection CFD validation New technologies New configuration concepts Reduction in testing time enabled by availability of mature and calibrated CFD Occupancy hours Tunnel testing time -25 % -30 % 767 777 787 (1980) (1990) (2005) Boeing s primary wind tunnel evaluation criteria: Technical viability can do the required Productivity complete required testing in a testing timely manner Accuracy and Validation results that can be trusted Availability ready and available when needed Reliability keeps working without interruption Security privacy and confidentiality assured Cost efficiency good value for the money Copyright 2011 Boeing. All rights reserved. Aerodays 2011 22

Types of wind tunnel testing Configuration development testing Incremental and absolute aerodynamic coefficient data Cruise, high-lift, and flight envelope limit data Airframe noise Propulsion installation Tare and interference testing Flow control concepts Alternate configurations will require significant additional testing Database development testing Airplane performance Stability and control including simulator database Aerodynamic loads throughout envelope Specialized testing Full scale Reynolds number Thrust reversers Ground effectec Ice accretion/ice effects Copyright 2011 Boeing. All rights reserved. Aerodays 2011 23

Primary wind tunnels used by Boeing Commercial Airplanes (2000 and on) Farnborough, UK Seattle, WA Minneapolis, MN Philadelphia, PA Cologne, Germany Gifu, Japan Mountain View, CA Hampton, VA Le Fauga, France Copyright 2011 Boeing. All rights reserved. Aerodays 2011 24

Flight testing aerodynamic technologies Flight testing for certification Flight testing for development/evaluation of aerodynamic technologies Certain technologies are difficult to simulate on scaled models in tunnel Concept to be flight tested must integrate with test vehicle Flight testing ti to provide operational experience Natural laminar flow Quiet-Technology Demonstrator (QTD2) Copyright 2011 Boeing. All rights reserved. Aerodays 2011 25

Future aerodynamics engineers Encourage youth into science, technology, engineering, math (STEM) careers Continuing education and on-the-job training i Retain knowledge from retiring senior engineers COLLEGE Nurture utuestudents ts through funded research, internships, scholarships, etc. Industry/ academia collaboration Encourage programs that teach teamwork, multi-disciplinary studies Copyright 2011 Boeing. All rights reserved. Aerodays 2011 26

Aerodynamic opportunities and challenges on alternate configurations Geometries tailored to enhance laminar flow control Aerodynamic surfaces designed for active flow control Skin friction control Advanced multidisciplinary optimization Control configured empennage Configuration optimized for noise Induced drag reduction with novel non-planar wing configurations Incorporation of novel propulsion systems (e.g., open fan) Boundary-layer ingestion for increased propulsion efficiency Advanced integration of aerodynamics, structures and systems Copyright 2011 Boeing. All rights reserved. Aerodays 2011 28

Alternate configuration concepts New challenges for aerodynamic design Aerodynamic tools and processes that have been refined for tube-and-wing configurations must be updated/calibrated d/ t d for non-classical l aircraft configurations Copyright 2011 Boeing. All rights reserved. Aerodays 2011 29

Commercial airplane aerodynamics: What is next? Readiness of advanced aerodynamic technologies Market requirements Regulatory requirements Future configurations Further significant reduction in fuel burn, noise, and emissions s Copyright 2011 Boeing. All rights reserved. Aerodays 2011 30

Summary Aerodynamics will be key contributor to the future of aircraft design Safety Efficiency Environmental compatibility The next decade of challenges will be multidisciplinary New aerodynamic technologies are on the horizon Integration with structures, propulsion, and systems, enabled by further computational advances Manufacturability and maintainability to introduce flow control methods Aerodynamic technologies, together with tools, processes, and people, will be keys to future advances Copyright 2011 Boeing. All rights reserved. Aerodays 2011 31