Visualized flow structure around and inside of one-sided wind-catchers

In this study, smoke visualization approach was used to investigate the main flow features around and inside various types of one-sided wind-catcher models. Wind-catcher models with flat, inclined or steep and curved roofs are used in the experimental flow measurement and flow visualization. Wind-catchers play an important role in creating natural ventilation and providing the thermal comfort for interior living spaces of various buildings. One-sided wind-catchers are used in locations where wind flows in predominantly known direction. In this type of wind-catchers, the tower has opening on one side only to capture wind and guide it into the building. By using smoke visualization techniques, detailed flow characteristics are revealed around and inside of typical one-sided wind-catchers. In order to examine the performance of wind-catchers quantitatively, induced airflow rate and pressure coefficients around internal surfaces of wind-catcher channel are also measured. Based on the visualized flow and measured quantities, it is shown that the flow pattern inside the wind catcher channel was strongly influenced by the geometry of wind-catcher roof. Test results show that the wind catcher with a curved roof is capable of capturing higher airflow and hence exhibits superior passive ventilation performance in comparison with the other two types.

► Flow visualization is used to explore flow structure in and around wind catchers.
► Three one sided wind catcher models are examined by measuring ventilation capacity.
► Flow pattern inside the wind catcher influenced by the geometry of wind-catcher roof.
► Top view flow patterns revealed two vortices inside the wind catcher openings.
► Curved roof wind-catcher ventilation capacity is higher than the two other types.