Simulation of natural convection of air in a square cavity using the gothic thermalhydraulic code

A numerical solution to the problem of natural convection of air in a square cavity geometry using the GOTHIC thermalhydraulic code is presented. The heat transfer and fluid flow for a specific fluid is reduced to Ra numbers. In the paper, four cases with different Ra numbers are considered. Predictions obtained are compared to a benchmark numerical solution. In addition, the effects of full-upwinding to both Nusselt numbers and Ra numbers with respect to predictions are considered. Lastly, the capability of GOTHIC to give accurate hydrogen dispersion can be assessed by comparing model predictions to experimental results.