151-0368-00L Aeroelasticity
| Semester | Autumn Semester 2020 |
| Lecturers | M. Righi |
| Periodicity | yearly recurring course |
| Language of instruction | English |
| Abstract | Introduction to the basics and methods of Aeroelasticity. An overview of the main static and dynamic phenomena arising from the interaction between structural and aerodynamic loads. |
| Learning objective | The course will provide a basic physical understanding of flow-structure interaction. You will get to know the most important phenomena in the static and dynamic aeroelasticity, as well as a presentation of the most relevant analytical and numerical prediction methods. |
| Content | Introduction to steady and unsteady thin airfoil theory, extension to three dimension wing aerodynamics, strip theory, overview of numerical methods available (panel methods, CFD). Introduction to unsteady aerodynamics (theory): Theodorsen and Wagner functions. Unsteady aerodynamics observed from numerical experiments (CFD). Generation of simplified mathematical models. Presentation of steady aeroelasticity: equations of equilibrium for the typical section, aeroelastic deformation, effectiveness of the aeroelastic system, stability (definition), divergence condition, role played by a control surface, control effectiveness, sweep angle, aeroelastic tailoring of bending-torsion coupling. Ritz model to model beams, use of FEM, modal condensation, choice of generalized coordinates. Presentation of dynamic aeroelasticity: assessment of dynamic aeroelastic response of simple systems. Flutter kinematics (bending-twisting). Dynamic response of a simplified wing. Numerical aeroelasticity (Test Cases extracted from the latest AIAA Aeroelastic Prediction Workshops). Aeroelasticity of modern aircraft: assessment of the effects induced by the control surfaces and control systems (Aeroservoelasticity), active controlled aircraft, flutter-suppression systems, certification (EASA, FAA). Planning and execution of Wind Tunnel experiments with aeroelastic models. Live-execution of an experiment in the WT of the ETH. Brief presentation of non-linear phenomena like Limit-Cycle Oscillations (LCO) |
| Lecture notes | A script in English language is available. |
| Literature | Bispilnghoff Ashley, Aeroelasticity Abbott, Theory of Wing sections, Y. C. Fung, An Introduction to the Theory of Aeroelasticity, Dover Phoenix Editions. |