15AE744 AERO-ELASTICITY syllabus for AE

Aeroelastic Phenomena:

Stability versus response problems, The aeroelastic triangle of forces, Aeroelasticity in Aircraft Design, Prevention of aeroelastic instabilities. Influence and stiffness coefficients. Flexure, torsional oscillations of beam, Differential equation of motion of beam.

Divergence of a Lifting Surface:

Simple two dimensional idealizations -Strip theory – Integral equation of the second kind – Exact solutions for simple rectangular wings – ‘Semi rigid’ assumption and approximate solutions – Generalized coordinates – Successive approximations – Numerical approximations using matrix equations.

Steady State Aeroelastic Problems:

Loss and reversal of aileron control – Critical aileron reversal speed – Aileron efficiency – Semi rigid theory and successive approximations – Lift distribution – Rigid and elastic wings. Tail efficiency. Effect of elastic deformation on static longitudinal stability.

Flutter Phenomenon:

Non-dimensional parameters – Stiffness criteria – Dynamic mass balancing – Dimensional similarity. Flutter analysis – Two dimensional thin airfoils in steady incompressible flow – Quasi steady aerodynamic derivatives. Galerkin method for critical flutter speed – Stability of disturbed motion – Solution of the flutter determinant – Methods of determining the critical flutter speeds – Flutter prevention and control.

Examples of Aeroelastic Problems:

Galloping of transmission lines and Flow induced vibrations of transmission lines, tall slender structures and suspension bridges.

Course outcomes:

After studying this course, students will be able to:

1. Apply the aero elastic phenomena.

2. Evaluate the steady state aero elastic problems and flutter phenomena.

3. Classify the types of aero elastic problems.

Graduate Attributes :

• Engineering Knowledge.
• Problem Analysis.
• Design / development of solutions
• Interpretation of data

Question paper pattern:

• The question paper will have ten questions.
• Each full question consists of 16 marks.
• There will be 2 full questions (with a maximum of four sub questions) from each module.
• Each full question will have sub questions covering all the topics under a module.
• The students will have to answer 5 full questions, selecting one full question from each module.

Text Books:

1. Y.C. Fung, “An Introduction to the Theory of Aeroelasticity”, Dover Publications Inc, 2008,ISBN13: 978-0486469362

2. E.G. Broadbent, “Elementary Theory of Aeroelasticity”, Bun Hill Publications Ltd., 1986

Reference Books:

1. R.L. Bisplinghoff, H.Ashley, and R.L. Halfmann, “Aeroelasticity”, II Edition Addison Wesley Publishing Co., Inc., 1996.

2. R.H. Scanlan and R. Rosenbaum, “Introduction to the study of Aircraft Vibration and Flutter”, Macmillan Co., New York, 1981.

3. R.D. Blevins, “Flow Induced Vibrations”, Krieger Pub Co., 2001