Flow Structure of Rooftop Vortices over a Low-rise Building at High Reynolds Number

Severe windstorms cause enormous damage, destruction, and failure of civil structures in the United States, with low-rise buildings being among the most vulnerable structures. Roof failures account for most initial damage, which is often initiated at the windward roof edges and corners, due to peak suctions induced by flow separation and rooftop vortices. There is a need to improve the understanding of the link between rooftop vortical structures and the peak pressures to enhance wind loading design standards, advance flow modeling, and create effective mitigation strategies to reduce the peak suction. The research aims to determine the correlation of unsteady, 3D rooftop vortices with roof surface pressure at high Reynolds numbers. Wind tunnel testing was conducted to measure flow field over the roof and surface pressure distribution of a model low-rise building at Florida International University’s Wall of Wind facility. Data obtained by Tomo-PIV and pressure tap system were analyzed to correlate the rooftop vortices to peak suctions. This work intends to improve our understanding of flow physics behind rooftop vortices in relation to peak suction events and facilitate development of wind mitigation strategies for low-rise buildings.