A FFT-based finite-difference solver for massively-parallel direct numerical simulations of turbulent flows. (15th October 2018)

• Record Type: Journal Article
• Authors: Costa, Pedro
• Is Part Of: Computers & mathematics with applications. Volume 76:issue 8(2018)
• Page Start: 1853
• Page End: 1862
• Publication Date: 2018-10-15
• Subjects: Direct numerical simulations -- Turbulent flows -- High-performance computing -- Fast Poisson solver; Electronic data processing -- Periodicals; Mathematics -- Data processing -- Periodicals; 510.28541
• DOI: 10.1016/j.camwa.2018.07.034
• Languages: English
• ISSNs: 0898-1221

Abstract

Abstract: We present an efficient solver for massively-parallel direct numerical simulations of incompressible turbulent flows. The method uses a second-order, finite-volume pressure-correction scheme, where the pressure Poisson equation is solved with the method of eigenfunction expansions. This approach allows for very efficient FFT-based solvers in problems with different combinations of homogeneous pressure boundary conditions. Our algorithm explores all combinations of pressure boundary conditions valid for such a solver, in a single, general framework. The method is implemented in a 2D pencil -like domain decomposition, which enables efficient massively-parallel simulations. The implementation was validated against different canonical flows, and its computational performance was examined. Excellent strong scaling performance up to 1 0 4 cores is demonstrated for a domain with 1 0 9 spatial degrees of freedom, corresponding to a very small wall-clock time/time step. The resulting tool, CaNS, has been made freely available and open-source.