Fast Generalized Multiscale FEM for Complex Media: Effortless Modeling of Topography and Heterogeneity

Numerical modeling of acoustic wave propagation is challenging for both classical finite difference methods and finite element approaches in the presence of irregular free surface topography and anomalies with high velocity contrasts. There is inaccuracy in modeling irregular boundaries in finite difference methods and time-consuming mesh generation for finite element methods. We present a hybrid approach to address these issues within the framework of the generalized multiscale finite element method (GMsFEM). In particular, we propose an efficient procedure to perform finite element based simulations without tedious mesh generation processes. The approach applies the GMsFEM to reduce computational complexity by utilizing two automatically generated grid systems. Using a complicated, 2D salt dome model, we demonstrate the accuracy of the GMsFEM solutions and the associated reduction in computing time by an order of magnitude.