A particle method for fluid-structure interaction simulations in multiple GPUs

Abstract

This chapter is a presentation of the programming philosophy behind a novel numerical particle method for the simulation of the interaction of compressible fluids and elastic structures, specifically designed to run in multiple Graphics Processing Units (GPUs). The code has been developed using the CUDA C Application Programming Interface (API) for fine-grain parallelism in the GPUs and the Message Passing Interface library (MPI) for the distribution of threads in the Central Processing Units (CPUs) and the communication of shared data between GPUs. The numerical algorithm does not use smoothing kernels nor weighting functions for the computation of differential operators. A novel approach is used to compute gradients using averages of radial finite differences and divergences using Gauss’ theorem by approximations based on area integrals around local spheres around each particle. The interactions of the particles inside the fluid are modelled using the isothermal, compressible Navier-Stokes equations and a simple equation of state. The elastic material is modelled using inter-particle springs with damping. Results show the potential of the method for the simulation of flows in complex geometries.