GPU Accelerated Spectral Element Methods: 3D Euler equations

Wednesday, 16 December 2015
Poster Hall (Moscone South)
Daniel S Abdi1, Lucas Wilcox2, Francis Giraldo1 and Timothy Warburton3, (1)Naval Postgraduate School, Monterey, CA, United States, (2)Naval Postgraduate School, Pacific Grove, CA, United States, (3)Rice University, Houston, TX, United States
A GPU accelerated nodal discontinuous Galerkin method for the solution of three dimensional Euler equations is presented. The Euler equations are nonlinear hyperbolic equations that are widely used in Numerical Weather Prediction (NWP). Therefore, acceleration of the method plays an important practical role in not only getting daily forecasts faster but also in obtaining more accurate (high resolution) results. The equation sets used in our atomospheric model NUMA (non-hydrostatic unified model of the atmosphere) take into consideration non-hydrostatic effects that become more important with high resolution. We use algorithms suitable for the single instruction multiple thread (SIMT) architecture of GPUs to accelerate solution by an order of magnitude (20x) relative to CPU implementation. For portability to heterogeneous computing environment, we use a new programming language OCCA, which can be cross-compiled to either OpenCL, CUDA or OpenMP at runtime. Finally, the accuracy and performance of our GPU implementations are veried using several benchmark problems representative of different scales of atmospheric dynamics.