Wave Finite Element Schemes for Vibrations and Noise Under Turbulent Boundary Layer Excitation

In the framework of finite elements based methods, this work proposes two numerical approaches to deal with the vibrations and noise induced by a random excitation on periodic and homogeneous structural systems. First, a 1D Wave Finite Element scheme is developed to deal with flat, curved and tapered finite structures. A single substructure is modelled using finite elements and one-dimensional periodic links among nodes are applied to get the set of waves propagating along the periodicity direction. The set of waves is then used to calculate the Green transfer functions between a set of target degrees of freedom and a subset representing the loaded ones. A 2D approach is also developed in combination with a wavenumberspace load synthesis to simulate the sound transmission of infinite flat, curved and axisymmetric structures: both homogenised and complex periodic models are analysed. The proposed numerical approaches are validated with analytical, numerical and experimental results and under different load conditions. From the experimental point of view, the approach is validated comparing results in terms of transmission loss evaluated on aircraft fuselage panels under diffuse acoustic field excitation