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Abstract Hurricanes cause severe damage and destruction when striking densely populated urban areas. However, the impacts of buildings on hurricane turbulence dynamics remain poorly understood due to limited high‐resolution simulations. This study aims to address this gap by resolving turbulent flows around buildings using large‐eddy simulation (LES) with immersed boundary method. Eleven high‐resolution LESs were conducted across a range of urban layouts, spanning flat, sparse, and dense canopies as well as low‐rise, staggered, and high‐rise configurations. First, the code was validated in a realistic configuration against measurements in Houston. Then, idealized runs were performed to characterize hurricane boundary layer (HBL) dynamics and distinguish them from non‐cyclonic atmospheric boundary layer (ABL) flows. Building height, spatial arrangement, and canopy density were shown to strongly influence wind dynamics, turbulence, and aerodynamic roughness length, with staggered dense canopies generating the greatest drag and wake turbulence. These results offer reliable benchmarks for modeling hurricane winds over cities within a roughness Reynolds number (Re∗) range of ∼104–106, beyond oversimplified urban parameterizations. HBL‐ABL comparisons show that hurricane rotation, characterized by Rossby (Ro) number, suppresses turbulence and eddy viscosity, and amplifies mean winds, doubling drag on tall buildings and invalidating the assumption that hurricanes behave like stronger ABL winds. Spectral, turbulence budget, and spatial correlation analyses further demonstrate that centrifugal forces and urban roughness break down large coherent eddies and alter their orientation. These findings provide new insights into hurricane rotational dynamics and urban canopy morphology, enabling improved hurricane forecasts of weather models over complex urban terrains.
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Wind load impact on tall building facades: damage observations during severe wind events and wind tunnel testing
As global urbanization accelerates, the construction of tall buildings has surged, becoming a defining feature of modern cityscapes. Tall buildings, while contributing to economic growth and urban development, face substantial risks from extreme wind events, such as hurricanes and downbursts. This study provides a comprehensive evaluation of the performance of tall building facades under severe wind conditions, with a focus on recent events that impacted the Gulf Coast of the United States, specifically in Houston, during May to July 2024, including a powerful derecho and Hurricane Beryl. Through extensive damage assessments of various tall buildings, this research highlights the different damages observed from these wind events, revealing critical vulnerabilities in tall building façades, particularly in relation to wind channeling effects in densely built urban areas. The observed damage patterns, including extensive glass breakage and façade failures, underscore the need for a reassessment of wind effects on tall buildings to better reflect the complex interactions between wind forces and urban environments. Additionally, by integrating real-world damage observations with wind tunnel simulations carried out at the NSF NHERI Wall of Wind Experimental Facility, this research offers valuable insights into the factors that may have influenced the observed damage. In this wind tunnel testing campaign, a series of aerodynamic testing of a tall building model under both atmospheric boundary layer and downburst winds were conducted. Additionally, interference effects are tested for both types of events. The preliminary findings have shown that downburst winds can have higher negative pressures compared to atmospheric boundary layer (ABL) which needs to be further studied including several downburst events to characterize the difference between both types of winds. Also, the results indicated the need to conduct a detailed interference study to compare ABL and downburst to properly include these effects for dense urban areas.
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- Award ID(s):
- 2146277
- PAR ID:
- 10576123
- Publisher / Repository:
- Frontiers Media S.A.
- Date Published:
- Journal Name:
- Frontiers in Built Environment
- Volume:
- 10
- ISSN:
- 2297-3362
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.3389/fbuil.2024.1514523
