Benchmarked simulations of natural convection airflow in a square cavity

Abstract

An open-source code, OpenFOAM, and two commercial finite volume packages are benchmarked for accuracy and convergence speed in solving steady natural convection airflows in a square cavity with adiabatic horizontal boundaries and with high temperature difference on the two vertical side walls. The compressible two-dimensional Navier–Stokes equations are solved at Rayleigh numbers 106 and 107 (steady flow for Rayleigh numbers less than 2 × 108) using seven different CFD algorithms, including both transient and steady flow solvers. Velocity fields, pressures, temperatures and Nusselt numbers are compared against well-established results for three benchmark test cases from the literature. Relative accuracy and CPU time are reported for each algorithm and for each of the three test cases, yielding benchmarked comparisons of OpenFOAM, STAR-CCM+, and ANSYS-Fluent solvers for low Mach number compressible airflows.