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.

Keywords:

• 2-D airflow
• ANSYS-Fluent
• CFD
• compressible airflow
• CPU time
• low Mach number
• natural convection
• non-Boussinesq conditions
• Nusselt number
• OpenFOAM
• Rayleigh number
• Simcenter STAR-CCM+
• square cavity
• steady flow
• temperature-dependent air properties

Acknowledgments

This work was carried out using the advanced computational infrastructure provided by the Hyak supercomputer system, funded by the Student Technology Fee at the University of Washington. The funding source had no involvement in the study design, nor in the collection, analysis or interpretation of data, in the writing of the report, nor in the decision to submit the article for publication.

Disclosure statement

The authors report there are no competing interests to declare

Additional information

Funding

Results were obtained as part of the research supported by the National Science Foundation through Grant CMMI-1301491.