# Experimental Simulation of Thunderstorm Profiles in an Atmospheric Boundary Layer Wind Tunnel
## 5 Conclusions  
This paper provides a description and analysis of a series of experiments performed in the Giovanni Solari Wind Tunnel at the University of Genoa in order to reproduce thunderstorm mean wind velocity and turbulence intensity profiles. In addition to standard devices, a specific grid-like device was designed in order to reproduce the nose-shape of the mean wind speed profile. The resulting measurements in terms of mean wind speed were found to fit well the target profile (i.e., the Wood and Kwok empirical model). It was found that different configurations of the modules provided a large range of variation for the height of the nose that could be significant for different types of structures, especially for tall buildings. In terms of turbulence intensity, despite the lack of an analytical model, the profiles obtained were considered to be acceptable based on existing experimental and full-scale measurements. The solution also appears very satisfactory in terms of flow uniformity. These results demonstrate that the nose shape of the mean wind velocity profile can be effectively generated in a traditional wind tunnel using a passive modular grid, which is a relatively simple and cost-effective way to simulate wind characteristics for WT testing on scaled structures. In conclusion, the proposed device offers a practical solution for the experimental simulation of nose-shaped profiles in order to evaluate thunderstorm-induced wind loads on structures using common geometric scales for building tests (e.g., 1:400). By employing various configurations of the grid modules, the device can be adapted to facilitate testing at smaller geometric scales, broadening its range of applicability. Moreover, it provides a more affordable approach for technical projects with respect to sophisticated solutions due to its simplicity and low cost. It is evident that the adopted setup lacks the ability to reproduce the non-stationarity features of thunderstorms, which may be crucial when conducting a detailed assessment of the thunderstorm loading on a structure. A comparison with experimental tests carried out with active grids, able to reproduce the main non-stationary features of thunderstorms, would enable an evaluation of their effective influence on the assessment of thunderstorm-induced loading on structures.  
Figure 9: (**a**) Cobra probe coordinates over the turntable; (**b**) Comparison between the measured profiles for the configuration P21 (x = 0 y = 0 corresponds to the turntable center).  
**Author Contributions:** Conceptualization: C.A.S. and F.T.; Methodology: A.B., C.A.S., F.T. and G.P.; Software: C.A.S.; Validation: A.B. and F.T.; Formal Analysis: C.A.S.; Investigation: C.A.S. and F.T.; Resources: A.B. and G.P.; Data Curation, C.A.S. and F.T.; Writing--Original Draft Preparation: C.A.S.; Writing--Review and Editing: A.B., F.T. and G.P.; Visualization: A.B. and C.A.S.; Supervision: A.B., F.T. and G.P. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This study was carried out within the RETURN Extended Partnership and received funding from the European Union Next-Generation EU (National Recovery and Resilience Plan--NRRP, Mission 4, Component 2, Investment 1.3--D.D. 1243 2/8/2022, PE0000005). The first author has a PhD scholarship financed by PON Project: \"Programma Operativo Nazionale Ricerca e Innovazione 2014-2020 (CCI 2014 IT16M2 OP005)\", risorse FSE REACT-EU, Azione IV.4 \"Dottorati e contratti di ricerca su tematiche dell'innovazione\" e Azione IV.5 \"Dottorati su tematiche Green\".  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** Data sharing not applicable (all relevant data is presented and included within the paper).  
**Acknowledgments:** The authors gratefully acknowledge [PERSON] and [PERSON] for the technical support during the wind tunnel experiments.  
**Conflicts of Interest:** The authors declare no conflict of interest.