Abstract
In this paper, some CFD (Computational Fluid Dynamics) calculations with the standard k-ε and low-Reynolds number k-ε model for the airflow and temperature distributions have been done for the experimental atrium. The simulation basis is the simplified experimental data, which is measured without air conditioning nor ventilation, and with air cooling. The numerical results are compared with experiments, and the effects of simplifications of the boundary conditions and the simulation conditions of CFD are discussed. Also discussed are the behavior of predicted heat transfer rates in CFD models of the standard k-ε and low-Reynolds number k-ε model. As a result, the following conclusions are revealed; (1) Effective in the natural convection case is the heat gain by the steel frame which has a large surface area comparing to the total surface area of the floor and wall. (2) On the whole, simplifications of the boundary conditions sometimes give us different properties of the indoor climate from the actual situation, however, small-scale changes of the boundary conditions have little influence on the mean flow pattern and temperature distribution. (3) The use of the low-Reynolds number k-ε model gives us more precise prediction results for the temperature distribution and the convective heat transfer rates.
