Experimental and numerical characterisation of the flutter speed of wings

Abstract

The flutter, is one of the most complex and dangerous aeroelastic phenomena. Nowadays, the certification authorities have to guarantee the non-appearance of this phenomenon, in such a way that the safety of the aircrafts is not compromised. The preliminary design of any aircraft includes an estimate of the flutter speed. This thesis focuses on studying the estimation of the flutter speed through several methods, including numerical and experimental approaches. The main target is the discussion of the results and the possibility to develop an accurate method to properly predict the flutter speed and its characteristics in the near future. Three different methods are used in this thesis; empirical formula, numerical and experimental methods, where the differences between the experimentation and theory will be commented. The combination of different numerical methods as Finite Elements Method and Vortex Lattice Method is used simultaneity alongside wind tunnel tests. Moreover, an empirical formula based on the geometrical parameters is analysed and commented in an attempt to discover and prove new ways to develop this concept of flutter acquisition. Finally, some range conditions for the validity of this empirical formula are defined in base of a comparison to the other methods.