Tornado-like-vortex-induced wind pressure on a low-rise building with opening in roof corner

This study focuses on internal pressures and wind forces on a gable roof of a low-rise building with an opening in the roof corner in stationary tornado-like vortices. Three roof corner opening sizes and one roof center opening size are tested. The influence of radial distance between building model and tornado center is also investigated. Results indicate that the roof corner opening ratio significantly influences the internal pressures and lift forces on a gable roof. With increase in opening ratio up to 8%, the mean internal pressure coefficient inside the tornado core decreases while the standard deviation increases. In addition, the mean internal pressure coefficient exhibits a minimum value when the building is located at 0.75 times the tornado radius with the roof opening on the windward side. The lift force on the roof may change direction from upward to downward depending on opening ratio and opening position. The coherence function of internal pressure in the high frequency band increases with increase in opening ratio. The correlation between internal and external pressures near the opening is high and increase with increase in opening ratio, which is different from those in straight-line winds.