Resumo

CONTRERAS, Xiomara  e  ALDANA, Milagrosa. Three strategies to solve the wave propagation problem in a 3d fluid-solid interface. Rev. Fac. Ing. UCV [online]. 2009, vol.24, n.4, pp.28-39. ISSN 0798-4065.

Two implicit strategies and an explicit approach have been used to solve the problem of a fluid-solid interface in a 3D medium. One of the implicit strategies considers a transitional zone and the other is the traditional one. To solve the boundary conditions at the interface using the explicit strategy, two planes of “fictitious points” were added to the grid. A predictorcorrector approach was considered in this case. A Finite Difference Staggered-Grid method was used to solve the wave propagation problem in all the cases. The results obtained show a marked difference between the three strategies. For the study configuration and the hardware and software conditions of this work, the traditional implicit strategy seems to better model the fluid-solid interface. In this case, the internal interface is not treated by explicit boundary conditions, as it is represented naturally by changes of the elastic parameters and the densities. On the other hand, the reflected wave field shows higher amplitudes than those expected for this problem in the images obtained with both, the explicit strategy and the one that incorporates the transitional zone. Such undesirable effects could be the result of the combination, in the first case, of the small size of the propagation volume considered in this work, the low performance of the boundary condition function applied at the external surfaces of the volume and the predictor-corrector method for the explicit strategy. The first two aspects combined with the presence of the transitional zone could be responsible of the behavior observed for the second implicit strategy

Palavras-chave : Interface; Fluid-solid; Wave propagation; Finite-difference; Staggered-grid.