CFD Modelling of Atrium-assisted Natural Ventilation

Using computational fluid dynamics (CFD) techniques to model buoyancy-driven airflows hasalways proved challenging. This work investigates CFD modelling of buoyancy-driven natural ventilation flows in a single-storey space connected to an atrium. The atrium is taller than the ventilated space and when warmed by internal heat gains producing a column of warm air in the atrium and connect space drives a ventilation flow. Results of CFD simulations are compared with predictions of an analytical model and small-scale experiments [1]. Using the RNG k-epsilon turbulence model the predicted airflow patterns and temperature profile agreed reasonably well between the three prediction techniques. The work demonstrates the potential of using CFD for modelling natural displacement ventilation and the accuracy that can be expected.