Wind tunnel and CFD study of the natural ventilation performance of a commercial multi-directional wind tower

Abstract

Scaled wind tunnel testing and Computational Fluid Dynamics (CFD) analysis were conducted to investigate the natural ventilation performance of a commercial multi-directional wind tower. The 1:10 scaled model of the wind tower was connected to the test room to investigate the velocity and pressure patterns inside the micro-climate. The tests were conducted at various wind speeds in the range of 0.5–5 m/s and various incidence angles, ranging from 0° to 90°. Extensive smoke visualisation experiments were conducted to further analyse the detailed airflow structure within the wind tower and also inside the test room. An accurate geometrical representation of the wind tunnel test set-up was recreated in the numerical modelling. Care was taken to generate a high-quality grid, specify consistent boundary conditions and compare the simulation results with detailed wind tunnel measurements. The results indicated that the wind tower was capable of providing the recommended supply rates at external wind speeds as low as 2 m/s for the considered test configuration. In order to examine the performance quantitatively, the indoor airflow rate, supply and extract rates, external airflow and pressure coefficients were also measured. The CFD simulations were generally in good agreement (0–20%) with the wind tunnel measurements. Moreover, the smoke visualisation test showed the capability of CFD in replicating the air flow distribution inside the wind tower and also the test room.