Design Optimization of

Airplanes/AeroplanesBY

DEEPAK . ROTTI

2GI13MMD07

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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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Design process: AirplanesDetailed design process

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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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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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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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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

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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Continued….

Wing Box Design variables:

Design Criteria: minimum feasible weight fulfilling criteria.

Wing Box Design Constrains:

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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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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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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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Internet source: 7.http://ec.europa.eu/research/transport/projects/ite

ms/cofcluo_en.htm

8. http://en.wikipedia.org/wiki/Multidisciplinary_design_optimization

9. http://www.meil.pw.edu.pl/add/ADD/Teaching/Subjects/Optimization-In-Aircraft-Design

10.http://www.lancs.ac.uk/~marshaj3/Group%20Website/Optimisation-NT.html

11. http://inventors.about.com/library/inventors/blairplanedynamics.htm

12. http://www.nasa.gov/audience/forstudents/k-4/stories/ames-how-do-planes-fly

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“”

THANK

YOUdeepak.rotti24@gmail.com

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