Grants and Contributions:

Grant or Award spanning more than one fiscal year (2017-2018 to 2018-2019).

There have been ever-growing economic and insured losses due to extreme weather over the past two decades.x000D
This is related to population growth, population migration to large cities and climate change. The Institute forx000D
Catastrophic Loss Reduction (ICLR) is working to develop mitigation strategy with a particular focus onx000D
earthquakes, flooding, extreme wind and wildfire. This proposal relates to mitigating the effects of extremex000D
wind, particularly, hurricanes and tornadoes. The primary challenge with mitigating wind loads in tornadoes isx000D
that building aerodynamics in tornadoes are largely unknown. The basic approach is to adopt the wind loads forx000D
'straight-line' winds (such as hurricanes), and apply a multiplication factor to adopt them for tornadoes. Thex000D
challenge for this is to separate the effects of the swirling vortical structures associated with tornadoes from thex000D
rest of turbulence, which affects both straight-line winds in the atmospheric boundary layer and tornadoes.x000D
The goal of this proposal is to better understand the role of turbulence, in support of ICLR's objective to definex000D
wind loads in tornadoes. More specifically, a time-resolved particle image velocimetry will be used to performx000D
velocity measurements in the wake flow generated by three-dimensional surface-mounted bluff bodiesx000D
immersed in deep turbulent boundary layers. The velocity data will be analyzed to develop scientificx000D
understanding of building aerodynamics, and potentially lead to the development of more reliable predictivex000D
models that will enable ICLR to develop more effective strategy for mitigating the effects of extreme wind,x000D
particularly, hurricanes and tornadoes. The results from this research will also help ICLR to define wind loadsx000D
in tornadoes by defining the role of turbulence more precisely.