The effects of roof angle and width of adjacent buildings on wind-induced cooling ventilation of atrium spaces

The wind-induced natural ventilation of atrium buildingswith two roof openings has been investigated using computational fluid dynamics (CFD) techniques. Three possible flow patterns are identified for an atrium buildingwith a section aspect ratio of unity: (I) when the main flow of the oncoming wind directly enters through the opening in the windward roof pitch and leaves from the leeward opening resulting in a recirculation in the space; (II) when the main flow of the oncoming wind separates at the windward top corner of the atrium and thus the airflow in the space is driven by the primary recirculationbelow the main flow; (III) when the main flow still separates at the windward top corner and leads to a recirculationat the roof level and the air movement in the space is driven by a secondary recirculation. For each flow pattern, the effects of the roof angle and the width of the adjacent buildings on the flow pattern and the air velocity field at occupant level are then studied and specific design guidelines are developed accordingly.