Parallel-in-Space-and-Time Simulation of the Three-Dimensional, Unsteady Navier-Stokes Equations for Incompressible Flow
This work addresses the need for additional speedup in CFD simulations after spatial parallelization saturates, offering a new direction for leveraging more cores.
The authors combined Parareal parallel-in-time with spatial parallelization to solve 3D incompressible Navier-Stokes equations, demonstrating speedup beyond spatial saturation using up to 2,048 cores on a Cray XE6 for driven cavity flow.
In this paper we combine the Parareal parallel-in-time method together with spatial parallelization and investigate this space-time parallel scheme by means of solving the three-dimensional incompressible Navier-Stokes equations. Parallelization of time stepping provides a new direction of parallelization and allows to employ additional cores to further speed up simulations after spatial parallelization has saturated. We report on numerical experiments performed on a Cray XE6, simulating a driven cavity flow with and without obstacles. Distributed memory parallelization is used in both space and time, featuring up to 2,048 cores in total. It is confirmed that the space-time-parallel method can provide speedup beyond the saturation of the spatial parallelization.