Optimised hybrid parallelisation of a CFD code on Many Core architectures

TL;DR

This paper presents optimized hybrid MPI-OpenMP parallelisation strategies for the COSA CFD code, enhancing computational efficiency and analyzing power consumption on various HPC systems.

Contribution

It introduces optimized hybrid parallelisation methods for COSA, improving performance and efficiency over traditional MPI-only approaches.

Findings

Hybrid parallelisation reduces simulation time.

Optimizations improve scalability on many-core architectures.

Power consumption analysis informs energy-efficient computing.

Abstract

COSA is a novel CFD system based on the compressible Navier-Stokes model for unsteady aerodynamics and aeroelasticity of fixed structures, rotary wings and turbomachinery blades. It includes a steady, time domain, and harmonic balance flow solver. COSA has primarily been parallelised using MPI, but there is also a hybrid parallelisation that adds OpenMP functionality to the MPI parallelisation to enable larger number of cores to be utilised for a given simulation as the MPI parallelisation is limited to the number of geometric partitions (or blocks) in the simulation, or to exploit multi-threaded hardware where appropriate. This paper outlines the work undertaken to optimise these two parallelisation strategies, improving the efficiency of both and therefore reducing the computational time required to compute simulations. We also analyse the power consumption of the code on a range of leading HPC systems to further understand the performance of the code.