WATCH THE PRESENTATIONTime-domain discontinuous Galerkin (DG) solvers combine high order accurate approximations with unstructured meshes, and are effective for the simulation of seismic wave propagation. DG solutions are allowed to be discontinuous across elements, and neighboring elements are coupled weakly through a numerical flux. The use of unstructured meshes in tandem with discontinuous approximations makes it possible to accurately capture sharp interfaces and geological features. Additionally, due to this weak coupling, DG solvers exhibit high parallel scalability, and benefit greatly from acceleration using Graphics Processing Units (GPUs). Finally, GPU-accelerated DG solvers have shown promise as efficient propagators for reverse time migration.
It is well known that high order DG on hexahedral meshes yields very efficient computational kernels due to the tensor product structure of hexahedra. However, producing high quality hexahedral meshes for complex domains is presently a difficult and non-robust procedure. Hybrid meshes, which consist of wedge and pyramidal elements in addition to hexahedra and tetrahedra, have been proposed to leverage the efficiency of hexahedral elements for more general geometries. We extend efficient DG solvers to hybrid meshes containing multiple types of elements, which have the potential to produce propagation models with improved accuracy at reduced computational cost. We propose efficient, low-storage implementations of DG on GPUs for each type of element and discuss the extension of multi-rate time stepping strategies for acoustic wave propagation to hybrid meshes.
