Programme

An introduction to the 2 dofs semi-rigid wing model, and derivation of the governing equations through application the Lagrangian formulation. Steady and quasi-steady, 2D, aerodynamic models for the aeroelastic analysis of the semi-rigid wing model. Study of aeroelastic flutter and divergence.

Theodorsen theory for 2D unsteady aerodynamics. V-g method for flutter analysis. Padè approximants of the `lift deficiency function' and related finite-state aeroelastic model. Correlation between Theodorsen theory and Wagner theory.

Aeroelastic modelling of 3D wings: bending-torsion structural dynamics model, `strip theory' aerodynamic model and application of the Galerkin method. Extension to swept wing analysis. Aeroelastic stability analysis.

Unsteady, 3D aerodynamics: incompressibe, inviscid flows; diffferential formulation for quasi-potential incompressible flows; boundary integral formulation for quasi-potential flows and panel method for its numerical solution. Definition of the aerodynamic matrix for aeroelastic stability analysis. Rational matrix approximation of the aerodynamic matrix, corresponding finite-state aeroelastic model and flutter analysis.

Aeroelastic model of wing section with trailing-edge flap. Actuation of flap for flutter suppression, as derived from application of optimal control theory with inclusion of an observer.

Core Documentation

Bisplinghoff, R.L., Ashley H., Halfman, R., Aeroelasticity. Dover Publications, 1996.
Hodges, D.H. and Pierce, A., Introduction to Structural Dynamics and Aeroelasticity. Cambridge Aerospace Series, 2002.

During the lectures, the teacher will suggest the student the most efficient way to use the proposed references, and will provide them with lecture notes.

Reference Bibliography

Fung, Y.C., An Introduction to the Theory of Aeroelasticity. Dover Publications, 1994. Wright, J.R. and Cooper, J.E., Introduction to Aircraft Aeroelasticity and Loads. Wiley and Sons, 2007. Dowell, E.H., A modern course in aeroelasticity. Kluwer Academic Publishers, 2004. Venkatesan, C., and Friedmann, P. P., “New Approach to Finite-State Modeling of Unsteady Aerodynamics,” AIAA Journal, Vol. 24, No. 12, 1986, pp. 1889–1897. Theodorsen, T., “General Theory of Aerodynamic Instability and the Mechanism of Flutter,” NACA Rept. 496, 1935. Morino, L., Gennaretti, M., “Boundary Integral Equation Methods for Aerodynamics,” Computational Nonlinear Mechanics in Aerospace Engineering, edited by S. N. Atluri, Progress in Astronautics and Aeronautics, AIAA, Washington, D.C., 1992, pp. 279–320. Gennaretti, M., Greco, L., "A time-dependent coefficient reduced-order model for unsteady aerodynamics of proprotors", Journal of Aircraft, Vol. 42, No. 1, 2005, pp. 138-147.

Type of delivery of the course

The course includes lectures, but also team exercises assigned during the course. Although recommended, course attendance is not mandatory.

Type of evaluation

The exam consists of a written test lasting 1 hour and a half, and an oral test. The written test includes several theoretical questions with open answers, aimed at assessing the level of actual understanding of the concepts and the ability to interpret them in real contexts. Passing the written test is a prerequisite for the oral exam. The oral test includes questions concerning theoretical and applied issues related to the entire program, as well as, the discussion of the team exercise performed during the course. The examination tests of previous years are made available by the teacher. During the Covid-19 emergency, the exam will consist exclusively on an oral test.