2-D unstructured simulation of acoustic scattering phenomena

Recently, a new experimental approach for acoustical scattering of elastic objects based on combination of quasi-Dirac spark source and high-speed shadowgraph visualization was successfully developed. Owing to its high spatial resolution, this method provides a new possibility to study precisely the process of generation and propagation of elastic waves created in the target and some new information were obtained for complex geometries. In order to provide a theoretical basis to better interpret experimental results obtained by the latter technique, a specific and original numerical method of finite volumes has been developed. The numerical procedure and results of simulation are presented in this paper for some various complex geometries. The behavior of Lamb waves is analyzed and compared with visualization results. A self-adaptation of the excited modes to the local thickness of target has been observed.