A communication-efficient, distributed memory parallel code using discontinuous Galerkin method for compressible flows

We present parallelization of a discontinuous Galerkin (DG) code on distributed memory parallel computers for compressible, inviscid fluid flow computations on unstructured meshes. The parallel DG code is based on a Taylor series basis and it uses LU-SGS (Lower-Upper Symmetric Gauss-Seidel) method for solving the linear system obtained by implicit time integration. Cost effective Ethernet based compute cluster composed of commonly available PC components is considered as the parallel computing platform. The parallel solution is based on computational domain partitioning and MPI (Message Passing Interface) programming paradigm. We demonstrate scalability of the developed parallel code on a cluster using two efficient MPI communication procedures. We also demonstrated the dominance of memory-bound nature of the parallel solution over network-bound nature.