High Performance 3D Unstructured Mesh Deformation Using Rank Structured Matrix Computations

Simulation of fluid-structure interactions involving moving 3D bodies requires computation of large mesh deformations. The Radial Basis Function (RBF) technique is an interpolation method that produces high-quality unstructured adaptive meshes. However, the RBF-based boundary problem necessitates solving a large dense linear system with cubic arithmetic complexity that is computationally expensive and prohibitive in terms of memory footprint. In this paper, we accelerate the computations of 3D unstructured mesh deformation based on RBF interpolations by exploiting the rank structured property of the matrix operator. The main idea consists in approximating the matrix off-diagonal tiles up to an application-dependent accuracy threshold. We highlight the robustness of our multiscale solver by assessing its numerical accuracy using realistic 3D geometries. In particular, we model the 3D mesh deformation and simulate the transport of the novel coronaviruses. We report and compare performance results on various parallel systems against existing state-of-the-art matrix solvers.