Investigation of Wind Load Behavior on Hip Roof Structures Subjected to Tornado-induced Flow.

This study investigates the effects of ground roughness, building orientation, swirl ratio, and radial position on the wind loads of hip roof buildings under tornado conditions. The simulation results (CFD) presented herein were compared with validated simulations, existing experimental data, and field measurements to validate the accuracy of the modelling approach. The most unfavorable vortex ratio affecting the hipped roof was identified through an analysis of the wind pressure coefficient under typical vortex ratios. The wind load characteristics at specific roof locations were examined by comparing radial distances. The influence of orientation angle on turbulent structures and wind pressure distribution within the wind field was investigated through comparative analysis of different aspects. This study investigates the influence of ground roughness on wind pressure and mean aerodynamic force over hipped roofs through computational analysis. Results indicate that increased surface roughness reduces the proportion of upward airflow, causing wind field characteristics to approach those of smooth surfaces. When the building orientation is 90°, the maximum negative pressure occurs at the leeward ridge junction due to minimal airflow separation and windward area. At the maximum core radius, airflow directly impacts the windward surface, inducing flow separation and vortex formation, which generates substantial vortices on the roof's leeward side. These findings provide quantifiable insights into the near-ground tornado-structure interaction, offering valuable guidance for optimizing design codes and enhancing the resilience of low-rise buildings in tornado-prone regions.