Mitigating wind suction of a flat roof using small horizontal-axis wind turbine

High wind suction always occurs at the edges and corners of large-span low-rise flat roofs; it can lead to severe damage to the roof elements, and even to the overall destruction of the roof. In this study, a horizontal-axis wind turbine is proposed to mitigate extreme wind suction on large-span low-rise flat roofs while harvesting wind energy. Experimental results reveal that positioning the turbine below roof height, facing windward and close to the roof significantly suppresses peak wind suction (54.2% reduction) and local time-averaged pressure (58.8% reduction). The mechanism stems from weakened conical vortices at roof corners due to turbulence induced by the turbine. The turbine-generated vortices entrain into conical vortices by way of upwash flow, shifting pressure energy from low- to high-frequency bands, although fluctuating pressures remain unaffected. Under optimal parameters, the extreme negative pressure coefficient at critical roof zones decreases from −3.43 to −1.57. These findings demonstrate the turbine’s dual benefits in structural protection and renewable energy utilisation, supporting sustainable building design.