Experimental Simulation of Thunderstorm Profiles in an Atmospheric Boundary Layer Wind Tunnel

Abstract

Thunderstorms have different features in comparison with synoptic events, including a typical nose-shaped mean wind speed profile and non-stationary characteristics in time intervals from 10 min to 1 h. The simulation of thunderstorms in traditional wind tunnels requires suitable devices in order to replicate their peculiar characteristics. Disregarding the non-stationary characteristics of thunderstorm outflows, this paper aims to study the possibility of adopting a passive device such as a specially designed grid in order to reproduce the nose-shaped mean wind speed profile. A widely adopted model of the mean wind velocity profile from the literature is employed as a target profile for the verification of the experimental findings. The results obtained show a good agreement between the measured and target mean wind speed profiles and an acceptable turbulence intensity level compared with full-scale and experimental measurements. The proposed device offers a practical and cost-effective solution to simulate the main characteristics of a thunderstorm event in a traditional atmospheric boundary layer wind tunnel, which could be adopted to assess the significance of thunderstorm loading on civil engineering structures and define the requirement for ad hoc specialist studies.

Keywords

• mean wind speed profile
• thunderstorm downbursts
• turbulence intensity profile
• wind tunnel tests