Transcript Slide 1
Aircraft Conceptual
Design Optimization
Kristian Amadori, Dr. Christopher Jouannet
Outline
Introduction
Design Framework
Test Case 1
Conclusions
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Introduction
System design is today characterized by:
Distribution
Collaboration
Competition
Subsystem/
design team
Subsystem/
design team
Subsystem
interface
System / system
integration group
Subsystem/
design team
Subsystem/
design team
Subsystem/
design team
We need tools for distributed system design that
handles these characteristics in early design stages
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Why?
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Introduction
Disciplinens
Table from: Nickol, C., “Conceptual Design Shop”, Presentation to Conceptual Aircraft Design Working Group
(CADWG21), Sept. 2004
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Design Framework
Based on Web Service Technology
Implements so-called Service Oriented Architecture (SOA)
Computational
Computational
model
model
User Client
Integration Service
and Data Repository
Network (SOAP messages)
Computational
Computational
model
model
User Client
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Computational
Computational
method
method
Design Framework
Connect together tools from different disciplines
Maintain system perspective
Spread sheet with
design analysis and
optimization tools
Allow for distribution
Design optimization
System Model
Wing
Wing
Fuselag
Fuselage
e
Perform
ance
Performance
Aircraft Sizing Model
Electric
Electric
Power
System
Power
Propulsi
Structure
on
Fuel
System
Fuel System
Sstem
Stability &
Stability
Control
&
Control
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Propulsi
Propulsion
on
Actuation
Actuatio
System
n
System
Aerodyn
amics
Aerodynamic
Optimization
Parametric CAD Modeling
Flexible geometries
Robustness
Hierarchical
Associative
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Parametrization
Various stages of Morphological instantiation
b
Script
Based
Relation
if shape = ”sq”
h { h = 10, b = h }
else { h = 10,
b = 2*h }
b
Mathematic Based
Relation
h
h = 10
b = 2*h
b
Parameterization
Fixed Object
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h = 10
h b = 20
Parametrization
Various stages of Topological instantiation
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Parametric CAD Modeling
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Parametric CAD Modeling
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Parametric CAD Modeling
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Parametric CAD Modeling
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Parametric CAD Modeling
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Aerodynamics
PANAIR
3D
Capable of analyzing any geometry
Fast
(Relatively) accurate
Tornado can be used (integrated to the framework)
Other CFD tools can be used if jugsed necessary
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Test Case:
Wing-Box Design Optimization
Wing-box structure optimization, given the air loads and a
predefined shape:
Position, orientation and thickness of ribs
Spars thickness
Skin thickness
Number of ribs
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Test Case:
The Optimization Problem
Problem formulated as:
min WW
s.t. MAX Allowed
Soft contraint formulation:
MAX
P K
Allowed
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Test Case:
Results (a)
Optimization stopped after 1000 trials with number of ribs are
fixed to 10 (left) or let vary between 5 to 15 (right)
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Test Case:
Results (b)
Optimization stopped after 20000 trials with number of ribs are
fixed to 10 (left) or let vary between 5 to 15 (right)
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Test Case :
Results Summary
1
0,9
0,8
Weight
Max Stress
Obj. Funct.
0,7
0,6
0,5
Fixed Nr.
Var. Nr.
1000 Iterations
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Fixed Nr.
Var. Nr.
20000 Iterations
Conclusions
Framework architecture that focuses on its flexibility of
application
How to proficiently include high-end CAD system into initial
geometry generation
Higher model flexibility increases chance to find better solution
KBE-techniques
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