Large-Scale Open-Jet Testing for Cladding Design in High-Rise Buildings: Higher Peak Pressures Compared to Wind Tunnels

Abstract

Recent aerodynamics studies suggest that previous wind tunnel testing may have underestimated peak wind loads on low-rise buildings. Also, climate change is demanding resilient constructions that can survive windstorms. The main objective of this study was to understand the reason for wind-induced damage to the cladding of high-rise buildings. We hypothesized that wall-bounded wind tunnels underestimate the peak loads that cause failure. We executed a unique large-scale (1∶50) experiment in an open-jet facility to test the hypothesis. The advantages of this kind of wind testing include reduced blockage effects and the capability to produce complete velocity spectral content at high Reynolds numbers. We emphasized the influence of aspect ratio and scale effects on the magnitudes and distribution of pressures. We compared results from this study with those from a small-scale wall-bounded wind tunnel to reveal the importance of testing at high Reynolds numbers. The findings suggested that while mean wind pressures on cladding and components are comparable to wall-bounded wind tunnel results, the peak pressures are different. The open jet produced higher peak pressures, revealing that our initial hypothesis was correct. The higher peak pressures toward the upper part of the building agreed with real-world observations of wind damage to cladding. In addition, the results showed that aspect ratio influences the mean and peak pressure distribution on the sidewalls.