Particle transport with unstructured grid on GPU

Abstract

The method of discontinuous finite element discrete ordinates which involves inverting an operator by iteratively sweeping across a mesh from multiple directions is commonly used to solve the time-dependent particle transport equation. Graphics Processing Unit (GPU) provides great faculty in solving scientific applications. The particle transport with unstructured grid bringing forward several challenges while implemented on GPU. This paper presents an efficient implementation of particle transport with unstructured grid under 2D cylindrical Lagrange coordinates system on a fine-grained data level parallelism GPU platform from three aspects. The first one is determining the sweep order of elements from different angular directions. The second one is mapping the sweep calculation onto the GPU thread execution model. The last one is efficiently using the on-chip memory to improve performance. As to the authorsʼ knowledge, this is the first implementation of a general purpose particle transport simulation with unstructured grid on GPU. Experimental results show that the performance speedup of NVIDIA M2050 GPU with double precision floating operations ranges from 11.03 to 17.96 compared with the serial implementation on Intel Xeon X5355 and Core Q6600.