Numerical simulation of single-sided ventilation using RANS and LES and comparison with full-scale experiments

Single-sided natural ventilation is a simple and energy-efficient method to passively cool a building, thus reducing or avoiding air-conditioning use. CFD has the potential to give detailed information about the complex flow generated by the interaction of buoyancy and wind in single-sided ventilation. In this paper, three experiments on single-sided ventilation are reproduced by CFD, using two turbulence models (RANS and LES). A detailed description of the experimental set-up, the numerical methods and the comparison method between experiments and simulations are provided. Results from RANS and LES are compared to experiments in terms of average and turbulent flow field, local airspeed, turbulence and temperature at the opening and airflow rates. The comparison shows that LES has the potential to provide more accurate results than RANS in most of the cases, capturing better the turbulent characteristics of the flow. However, the computational cost of LES is at least an order of magnitude higher than that of RANS.

► We compare the CFD using LES and RANS turbulent models with full-scale experiments.
► The buoyancy and wind interactions according to different conditions are analyzed.
► The experimental conditions include leeward and windward openings.
► In leeward conditions, a vortex behind the building counteracts the buoyancy effect.
► The ventilation rate is calculated from CFD results similar to gas tracer technique.