proopt saab aerosystems¶nköping 2010-10-07... · content background gripen spacecraft adapter...
TRANSCRIPT
Optimeringsdriven design vid Saab Aerosystems
Jönköping, 7 Oktober, 2010Torsten Bråmå
Content
� Background
� Gripen
� Spacecraft adapter
� Aerodynamic optimization
2010-10-07
Opimeringsdriven Design, Torsten Bråmå2
� Aerodynamic optimization
� Airbus A380
� Clean Sky – Smart Fixed wing aircraft
� Gripen NG
� Role of optimization in the design process
Complete aircraft responsibility
Gripen – multi-role fighter
Neuron – unmanned demonstrator in European cooperation, Dassault et al.
2010-10-07
Opimeringsdriven Design, Torsten Bråmå3
Complete aircraft responsibility
Saab 2000 FE model
Saab 2000 AEW&C
2010-10-07
Opimeringsdriven Design, Torsten Bråmå4
Saab 2000 FE model
FE model Gripen one and two seater versions
2010-10-07
Opimeringsdriven Design, Torsten Bråmå5
Bakgrundverktyg för optimering av kompositvingar
För att utnyttja potentialen som finns i användningen av komposit i vingstrukturer behövs datorbaserade stöd för att klara jobbet.
Under perioden 1975-90 utvecklades sådana av flera tillverkare:• USA – TSO, ASTROS m.fl. (F16, F18, F22, F35 etc)• Storbritannien – Stars, ECLIPS (Eurofighter, Gripen vinge)• Frankrike – ELFINI (Mirage, Rafale, Neuron)• Tyskland – Lagrange (Eurofighter)
2010-10-07
Opimeringsdriven Design, Torsten Bråmå6
• Tyskland – Lagrange (Eurofighter)• Sovjet – Argon (?)• Sverige – OPTSYS (Gripen vinge, fena, roder mm)
Under 90-talet började kommersiella verktyg utvecklas.
Idag finns Nastran Sol 200 som kan hantera en hel del av det ovanstående program klarar.
Bakgrundverktyg för strukturanalys och optimering på Saab
Omkring 1980 valdes FE-systemet ASKA för användning i projekten Gripen och Saab 340.
1983 påbörjades utvecklingen av OPTSYS (Saab, KTH, FFA), ett system för strukturoptimering integrerat med ASKA.
Under 1990-talet introducerades FE-systemet UAI-Nastran på Saab parallellt med ASKA. Nastran blir nära nog standard inom flygindustrin (undantag Dassault). Optsys integrerades med UAI-Nastran.
2010-10-07
Opimeringsdriven Design, Torsten Bråmå7
Optsys integrerades med UAI-Nastran.
Saab går över till MSC-Nastran (Gripen Demo, Airbus, Boeing). (MSC köper upp UAI)
MSC-Nastran kan inte integreras med Optsys men har utvecklat egen optimering i form av Sol 200.
2007-2008 genomförs utvecklingsprojekt för att kunna använda Nastran Sol 200t.ex i projekten Gripen NG och Clean Sky.
Objective: Minimum weight
Constraints:• Free from flutter within flight envelope
• Control surface efficiency to assure aircraft performance
• Strain in carbon fibres
Gripen wing: Problem formulation
2010-10-07
Opimeringsdriven Design, Torsten Bråmå8
• Panel buckling
• Design rules
Design variables:• Number of 0, 90 and +-45 degree composite layers
Composite material design variables:
90o � x2
0o � x1
+45o � x3
-45o � x3Total thickness
2010-10-07
Opimeringsdriven Design, Torsten Bråmå9
� 3 design variables controlling each layup
symmetric
thickness
Composite material design rules included as constraints:
• Layer thickness treated as a discrete or continuous variable.
• Stack assumed to be well mixed, no explicit layup treated.
• Each layer direction between 10% and 70% of total panel thickness.
• Minimum / maximum total panel thickness
• Fiber strain < 0.43%
• Panel buckling criteria:
2010-10-07
Opimeringsdriven Design, Torsten Bråmå10
• Panel buckling criteria:
Using in-house software integrated into Nastran.Panel layup and boundary loads received from Nastran.Additional input of panel size and boundary conditions required.
• Inner elevon deflected to achieve roll moment, Mx, at Mach 0.9
• Mx is reduced due to aeroelastic wing deformation
Gripen wing, control surface efficiency
2010-10-07
Opimeringsdriven Design, Torsten Bråmå11
wing deformation
• Efficiency=Mx(elastic) / Mx(rigid)
• A to flexible wing can result in zero or negative efficiency
Structural analysis
MassFibre strain
Panel buckling
g(X) , dg/dX
Minimize Objective(X)
Gradient based optimization
2010-10-07
Opimeringsdriven Design, Torsten Bråmå12
Flutter damping
Control efficiency
g(X) < gmax
Xmin < X < Xmax
Xn+1
2010-10-07
Opimeringsdriven Design, Torsten Bråmå13
2010-10-07
Opimeringsdriven Design, Torsten Bråmå14
Objective: Minimum weight
Constraints:• Frequencies of first lateral and axial mode
• Static axial load distribution in lower joint
• Strain in carbon fibres
Spacecraft adapter: Problem formulation
2010-10-07
Opimeringsdriven Design, Torsten Bråmå15
• Strain in carbon fibres
• Stress in upper aluminum ring
Design variables:• Thickness in upper aluminum ring (29 variables)
• Number of 0 and +-45 degree composite layers (96 variables)
2010-10-07
Opimeringsdriven Design, Torsten Bråmå16
2010-10-07
Opimeringsdriven Design, Torsten Bråmå17
2010-10-07
Opimeringsdriven Design, Torsten Bråmå18
2010-10-07
Opimeringsdriven Design, Torsten Bråmå19
Event Date
Concept study Aug-Sep 1998
Request for proposal Oct 1998
Opt. Iteration #1 Oct 1998 (~ 3 weeks)
Contract awarded Dec 1998
Opt. Iteration #2 Jan 1999 (~ 4 weeks)
Spacecraft adapter: Schedule / Milestones
2010-10-07
Opimeringsdriven Design, Torsten Bråmå20
Opt. Iteration #2 Jan 1999 (~ 4 weeks)
Hardware manufacturing May-Aug 1999
Test activities Oct 1999
Delivery to customer Nov 1999
Lift
Moment
• Objective function: minimize Drag
• Physical Constraints: - Constant Lift- Constant Pitching Moment- Flow Equations (transonic flow)
Aerodynamic shape optimizationIn-house progran Cadsos, ref. Per Weinerfelt
2010-10-07
Opimeringsdriven Design, Torsten Bråmå21
Drag
Moment- Flow Equations (transonic flow)
• Geometrical Constraints:- Prescribed volume- Given wing thickness at specified locations
Aerodynamic Shape OptimizationAerodynamic Shape Optimization
XXX
KkMXCMXC
KkMXCMXC
MXCMin
kMkM
kLkL
kD
K
kk
≤≤=≥
=≥∗
∗
=∑
,...,1),,(),(
,...,1),,(),(
),(
maxmin
1
λ
Drag minimization under lift, moment and geometrical constraints
original
2010-10-07
Opimeringsdriven Design, Torsten Bråmå22
equationsflowStokesNavierEuler
XXX
−≤≤
/maxmin
λk are weights, X design parameters and Mkdifferent Mach numbers
Saab has participated in the EU-projectAeroshape.(Aerodynamic Shape Optimization)
Pressure distr. over an original and optimized SCT
optimized
Coupled Structure/Aerodynamic OptimizationCoupled Structure/Aerodynamic Optimization
)()( 21 XCXwMin Dλλ +
StructureFE-models
FlutterUnsteady aero
model
Drag and weight minimization under physical and geometrical constraints
Design variables X:•Wing thickness•Wing twist •Wing profile •Structural dimensions
Steady
2010-10-07
Opimeringsdriven Design, Torsten Bråmå23
X
ff
∂∂
,
Static aeroelasticityNeutral model
Redesign1+nX
Saab has experience from the EU-projectsMDO and MOB. Also applied for internal military aircraft wing studies.
•Structural dimensions
Constraints:•Lift and moment•Stress, panel buckling•Flutter, control surface efficiency•Manufacturing requirements•Geometry
Steady Aerodynamics
AIRBUS A380
2010-10-07
Opimeringsdriven Design, Torsten Bråmå24
AIRBUS A380
2010-10-07
Opimeringsdriven Design, Torsten Bråmå25
Optimization study: Track Rib 10 (A380-800)
2010-10-07
Opimeringsdriven Design, Torsten Bråmå26
Programvara: Altair HyperWorks
HyperMesh• Geometrimodifiering, uppstädning
• Meshning och meshmodifiering (2D, tet, hex mm.)
• Översättning av indatafiler mellan program
• Definition av optimeringsproblem för exekvering i OptiStruct (målfunktion, bivillkor etc.)
• Applicering av formvariabler (Mesh Morphing)
• Postprocessor (mest HyperView)
2010-10-07
Opimeringsdriven Design, Torsten Bråmå27
• Postprocessor (mest HyperView)
OptiStruct• Inbyggd linjär Fe-lösare
• Bygger på Nastran kod
• Linjär statik, egenfrekvens, linjärbuckling, gap-element
• Inbyggd optimerare – gradientmetod med störningsvektor som opererar på styvhetsmatrisen
ComparisonOriginal Track Rib 10 Topology optimized Track Rib 10
2010-10-07
Opimeringsdriven Design, Torsten Bråmå28
Size and shape optimizationResults, part 3
2010-10-07
Opimeringsdriven Design, Torsten Bråmå29
Clean Sky - Smart Fixed Wing Aircraft
2010-10-07
Opimeringsdriven Design, Torsten Bråmå30
Key Smart Fixed Wing Aircraft technologies
Innovative Powerplant Integration� Technology Integration
� Large Scale Flight Demonstration
Smart Wing Technologies�Technology Development
�Technology Integration
� Large Scale Flight Demonstration
� Natural Laminar Flow (NLF)
� Hybrid Laminar Flow (HLF)
� Active and passive load control
� Novel enabling materials
� Innovative manufacturing scheme
SAGE ITD – CROR engine
SGO – Systems for Green Operation
Input connecting to:
2010-10-07
Opimeringsdriven Design, Torsten Bråmå31
� Large Scale Flight Demonstration
� Impact of airframe flow field on Propeller design (acoustic, aerodynamic, vibration)
� Impact of open rotor configuration on airframe (Certification capabilities, structure, vibrations...)
� Innovative empennage design
TE– SFWA technologies for a Green ATS
Output providing data to:
ICAS conference Nice, 19.-24.Sept. 2010
SFWASFWA-- High Speed Demonstrator Passive High Speed Demonstrator Passive (HSDP)(HSDP)
Smart Passive Laminar Flow Wing� Design of an all new natural laminar wing
� Proof of natural laminar wing concept in wind tunnel tests
� Use of novel materials and structural concepts
� Exploitation of structural and system integration together with tight tolerance / high qualitymanufacturing methods in a large scale ground test demonstrator
� Large scale flight test demonstration of the laminar wing in operational conditions
2010-10-07
Opimeringsdriven Design, Torsten Bråmå32
Port wing
Laminar wing structure concept option 2
Starboard wing
Laminar wing structure concept option 1
ICAS conference Nice, 19.-24.Sept. 2010
Worksharing to design and build the “HSDP” Smart Wing demonstrator
Wing Tip: Aernnova
2010-10-07
Opimeringsdriven Design, Torsten Bråmå33
Aileron structure (INCAS)
Integrated upper cover (SAAB)
Integrated upper cover with structural concept (SAAB)
ICAS conference Nice, 19.-24.Sept. 2010
Clean Sky SFWA: FE model (Nastran)
2010-10-07
Opimeringsdriven Design, Torsten Bråmå34
Clean Sky SFWA, Nastran SOL200 results,thickness distribution in composite upper panel and rear spar
2010-10-07
Opimeringsdriven Design, Torsten Bråmå35
Gripen Demo
2010-10-07
Opimeringsdriven Design, Torsten Bråmå36
Problem formulation
Parametric design
Role of optimization in the design process
2010-10-07
Opimeringsdriven Design, Torsten Bråmå37
Analyses
OptimizationObjective function – to maximize
Constraints – to satisfy
Variables – parameters to modify
WeightCostSafety
Performance
• Weight reduction
• Finding feasible designs
• Evaluating and comparing design concepts
Role of optimization in the design process
2010-10-07
Opimeringsdriven Design, Torsten Bråmå38
• Investigation of Cost–Performance relation
• Model updating with respect to test results
Examples of engineering tasks where optimization tools have proved to be useful
www.saabgroup.com
2010-10-07
Opimeringsdriven Design, Torsten Bråmå39