Large-eddy simulation of wind loads on a roof-mounted cube: application for interpolation of experimental aerodynamic data

Abstract

Failure of roof-mounted equipment in extreme wind events such as hurricanes is a significant contributor to wind-related property loss. Proper understanding of the nature and magnitude of wind-induced loads on these structures is essential to ensure their safety during severe storm conditions. Previous studies showed that wind loads on roof-mounted equipment vary significantly depending on the shape, size, location, and elevation relative to the roof surface. In this study, using large-eddy simulation (LES), wind loads on cube-shaped equipment mounted on the roof of a low-rise building are investigated to study the effect of equipment elevation on the wind loads aiming to complement existing experimental aerodynamic data. The accuracy and reliability of the LES results are assessed stage by stage. First, the characteristics of the incident wind profiles reported in the experimental study are reproduced in LES. Then, surface pressure distribution and force coefficients found from the LES are validated against the experimental aerodynamic data for selected representative cases. Finally, the variations of peak drag and uplift force coefficients with different equipment elevations are investigated in detail with the help of the flow field acquired from the LES near the rooftop equipment. The results from the current work show that the peak uplift force coefficients are significantly reduced for elevated equipment. However, considering all the cases studied, the peak drag force coefficients remain relatively unchanged with equipment elevation.