On pragmatic parallelization of a serial Navier‐Stokes solver in cylindrical coordinates

Abstract

PurposeThe purpose of this paper is to describe a pragmatic parallelization of a publicly available serial code aimed for direct numerical simulations of turbulent flow fields. The code solves the full Navier‐Stokes equations in a cylindrical coordinate system.Design/methodology/approachThe parallelization is performed by a single program multiple data approach using the Message‐Passing Interface (MPI) Library for processor communication.FindingsIn order to maintain the original coding of the subroutines, two obstacles had to be overcome. First, special attention had to be given to the inversion of the sparse matrixes from the linear terms in the Navier‐Stokes equations solved by an implicit scheme. Second, the serial FFT‐routines, needed for the direct Poisson‐solver, had to be replaced by parallel versions. Two directions of parallelization were tested. Parallelization in the axial direction turned out to be more efficient than parallelization in the circumferential direction.Originality/valueThis paper presents a pragmatic parallelization of an open source finite difference code and should be useful to researchers in the field of numerical methods for fluid flow who need to parallelize a numerical code.