Optimization is a method of searching of best available value for a given objective function w.r.t constrains. Airplanes always need improvement in their design as part of evolution and survival.

1. Design Optimization of
Airplanes/Aeroplanes
BY
DEEPAK . ROTTI
2GI13MMD07
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2. INTRODUCTION:
 Optimization: Method of searching of best
available value for a given objective function
w.r.t constrains.
 Multidisciplinary design optimization.
 Key aspects: multi-variable, Objective oriented,
constrained.
 Solution: closed-form solution, or a numerical
solution .
 Airplanes: Basics & working.
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3. Design process: AirplanesDetailed design process
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4. Optimization of an Aircraft
Design Problem:
 Arrangement of aircraft design problem.
 Analysis grouped into three disciplinary units,
aerodynamics(j1), structures(j2), and performance(j3).
 Maximize range(R ) with a specified gross weight.
Method:
Result:
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5. Optimization problems:
 Single variable optimization :
 Illustration: Boeing 777-class airliner.
 Variable: Program value.
 Objective: Maximizing net present value (NPV).
 Multivariable optimization:
 Illustration: Fairchild Dornier regional aircraft(728 series).
 Variables: stress, fatigue, buckling, control surface
effectiveness, flutter and weight.
 Objective: Maximizing wing strength minimizing cost etc.
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6. Single variable Optimization
 Program value based optimization- design vector & financial
model
 Net present value(NPV)—Dynamic programming.
 Models
 Simulation model- Annual cost & revenue estimates.
Input: design vector
 Physical model- Aerodynamics, weight& performance.
input: aircraft parameters (Lift)
 Financial model- Actual cost, price, &demand estimates.
Input: range & no. of passengers
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7. Continued…
 Value of models: measured in terms of expected NPV
Outputs: A set of program “decision rules”-optimal
conditions for design and production scheduling. as a
function of time and current market condition
 Model Validation: Outputs from the simplified value model
were benchmarked against NPV estimates.
 Optimization Framework: A design optimization framework
coupled the performance and financial models with an
optimization routine
 Optimization Results:
Optimization Results: 7

8. Multi-variable Optimization
 Wing box Design of FD aircraft-lower panel, the spars and
the internal ribs-skin stiffened by rectangular stringers.
 F.E Model of Wing Box: Shell and Beam elements
representing skin and stringers/stiffeners respectively.
 The Design Model: structural sizes of the wing box comprise
the skin thickness and the stringer height & thickness.
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9. Continued….
 Wing Box Design variables:
 Design Criteria: minimum feasible weight fulfilling criteria.
 Wing Box Design Constrains:
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10. Results for wing box:
 Sizing as per aero elastic requirements was
performed after achieving an optimum
design.
 Property update for the whole model
performed using a specially developed
update tool.
 Conceived wing design was subjected to
analysis under all loading and aero elastic
conditions.
 Typical results from this analysis are
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11. Conclusion:
 Optimization in airplanes is possible on various Levels.
 Application of these techniques bring about better flying
characteristics, Fuel economy and optimum payload.
 Framework for coupled performance and fuel efficient
aircraft design optimization.
 Additional optimization other than design
 Implementation on industrial level requires:
 Special team dedicated for MDO process
 Development of various pre- and post processing tools
 Detailed design model satisfying requirements
 Close coordination and cooperation of all design groups
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12. References
 1. Airplane Design with Aerodynamic Shape Optimization by
Antony Jameson & Thomas V. Jones , Professor of Engineering
Aeronautics & Astronautics Department, Stanford University.
 2.Multidisciplinary Optimization Methods for Aircraft Preliminary
Design by Ilan Kroo, Steve Altus, Robert Braun, Peter Gage, and
Ian Sobieski, Aircraft Aerodynamics and Design Group
Department of Aeronautics and Astronautics Stanford University,
Stanford, California.
 3.Value-Based Multidisciplinary Optimization for Commercial
Aircraft Design by Ryan Peoples, Karen Willcox Massachusetts
Institute of Technology, Cambridge, MA 02139.
 4.Multidisciplinary Design Optimization Of A Regional Aircraft Wing
Box by G. Schuhmacher, I. Murra , L. Wang, A. Laxander, O. J.
O’Leary and M. Herold Fairchild Dornier GmbH, 82230 Wessling,
Germany MDO.
 5. Airplane Design with Aerodynamic Shape Optimization by
Antony Jameson Thomas V. Jones Professor of Engineering
Aeronautics & Astronautics Department, Stanford University
 6. Book: Introduction to optimum design by Jasbir.S.Arora.
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13. Internet source:
 7.http://ec.europa.eu/research/transport/projects/ite
ms/cofcluo_en.htm
 8.
http://en.wikipedia.org/wiki/Multidisciplinary_design_o
ptimization
 9.
http://www.meil.pw.edu.pl/add/ADD/Teaching/Subje
cts/Optimization-In-Aircraft-Design
 10.http://www.lancs.ac.uk/~marshaj3/Group%20Websi
te/Optimisation-NT.html
 11.
http://inventors.about.com/library/inventors/blairplan
edynamics.htm
 12. http://www.nasa.gov/audience/forstudents/k-
4/stories/ames-how-do-planes-fly
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14. “
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THANK
YOU
deepak.rotti24@gmail.com
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