Scattering of complex geometries by Finite Element Method

Nuria González-Salido , Alan Islas-Cital , F. Camarena , Ruben Pico , P. R. Atkins

The back-scattering of complex finite geometries targets to plane incoming waves is investigated. The information obtained from the echoes (amplitude and phase) is used to characterize certain properties of the scatterers as the shape, size or orientation. Simple geometries as spheres, cylinders and spheroids are often used in underwateracoustic and medical imaging to model the different the scattering of structures, such as fish swim bladders, blood cells, or the fibbers of heart. Theoretical models include the effects of diffraction, reflection and transmission adapted to the shape, composition and size relative to the wavelength of the different objects. In particular, there are analytical solutions derived by Faran forsimple geometries such as sphere and cylinder, but for the other cases, numerical methods like T-matrix, or approximate simple solutions must be used. In this work, the finite element method was used to model the scattering from submerged targets with these simple geometries and elastic and rigid boundary conditions. A vibroacoustic model is used to couple the structure with the surrounding fluid medium. Numerical results show good agreement when compared with theoretical predictions and experimental data.

Mots clés: Scattering; finite element method

Domaines: Acoustique [physics.class-ph]

Nuria González-Salido, Alan Islas-Cital, F. Camarena, Ruben Pico, P. R. Atkins. Scattering of complex geometries by Finite Element Method. Acoustics 2012, Apr 2012, Nantes, France. ⟨hal-00811322⟩