Thunderstorm Downbursts and Wind Loading of Structures: Progress and Prospect

Abstract

In 1961, Davenport published a paper, considered by most to be a critical work in the study of wind engineering, in which meteorology, micrometeorology, climatology, aerodynamics, and structural dynamics were embedded in a homogeneous framework of the wind loading of structures. This framework, known as Davenport chain and based on a wind model coherent with synoptic-scale extra-tropical cyclones, is so limpid as to become a sort of axiom. In 1977, Gomes and Vickery separated thunderstorm from non-thunderstorm winds, evaluated their extreme wind speed marginal distributions, and from them obtained a mixed statistical model later generalized to other wind types. This viewpoint, dealt with as a milestone in the emerging issue of mixed climatology, pointed out the difficulty of labeling a heterogeneous set of phenomena endowed with different velocity fields, frequencies, durations, and sizes by the generic term "wind." Many wind types, in particular tropical cyclones, tornadoes, and downslope winds are typical of limited and well-known areas. Extra-tropical depressions and thunderstorms are natural hazards that affect the whole planet. This paper provides a state-of-the-art discussion of thunderstorm downburst, one of the most spectacular and damaging events caused by nature, and its wind loading of structures. Also, in light of the planet's climatology evolution, this topic is a key issue of structural safety and sustainability.

A climatology-based wind speed map for NBR 6123

“…From the observation that non-synoptic meteorological events determine extreme wind speeds in the majority of the Brazilian territory, and considering that design criteria and aerodynamic coefficients given in current wind codes were developed considering synoptic winds, a question arises about the possibility of establishing separate design procedures and maps for synoptic and non-synoptic winds. The specialized literature [34], [35], however, points to the impossibility of such division at present time, due to the lack of analytical models of universal acceptance which correctly represent the flow characteristics of non-synoptic events, and of their interactions with constructions. Moreover, as pointed out above, in the same meteorological event the mutual occurrence of synoptic and non-synoptic winds is possible, increasing the difficulty for separate consideration of these wind types.…”

Applications of Machine Learning to Wind Engineering

“…A thunderstorm is short-lived atmospheric weather system accompanied by lightning and thunder, gusty winds, heavy rain, and sometimes hail (Solari 2020). The life cycle of a thunderstorm usually consists of cumulus stage, mature stage and dissipative stage, and it typically lasts around 30 min.…”

“…Downbursts are one of the most spectacular and dangerous events resulting from thunderstorms (Solari 2020). Their radial outflows and ring vortices after touchdown produce strong wind gusts very close to the ground and therefore lead to substantial structural damages (e.g., Yang et al, 2018).…”

Sensitivity analysis of mesoscale simulations to physics parameterizations over the Belgian North Sea using Weather Research and Forecasting – Advanced Research WRF (WRF-ARW)

“…Extreme weather phenomena such as low-level jets, fast changes in wind direction, extreme wind shear (Kalverla et al, 2017;Aird et al, 2021), wind ramps (Gallego-Castillo et al, 2015), and storms (Solari, 2020) are capable of causing severe dynamic loading on wind turbines (Negro et al, 2014;AbuGazia et al, 2020;Chi et al, 2020). Furthermore, precipitation associated with these phenomena can lead to early blade degradation through leading-edge erosion (Law and Koutsos, 2020).…”