Tornadoes have caused severe disasters around the world, and have been one of the most violent and damaging natural hazards to human life and property. Experimental simulation of tornado-like vortices is an important method to investigate the effects of tornadoes. In a recent study published in the KeAi journal Advances in Wind Engineering , a group of researchers from China reported a new large-scale Ward-type tornado simulator at Central South University.
In this study, stationary tornado-like vortices were generated and tested in the simulator to explore the characteristics of the three-dimensional velocity field and surface pressure field under different fan speeds and swirl ratios.
“The measured vortices were compared with those of real tornados and numerical models proposed by previous researchers to validate the performance of the simulator,” explains lead author Haiquan Jing. “Our results showed that the simulator successfully reproduced the main characteristics of tornado-like vortices as other simulators, such as WindEEE, VorTECH, and ISU simulator.”
Notably, the fan speed only affected the magnitude of wind speed and had little effect on the vortex structures. The swirl ratio had a significant influence on the vortex structures.
“The simulated results of velocity and surface pressure are close to those of real tornadoes. Moreover, the simulated vortex apparently transformed from a narrow one-celled vortex to a two-celled vortex when the swirl ratio raised from 0.18 to 0.87,” adds Jing.
A downdraft appears at the upper vortex core when the swirl ratio is 0.42 and moves downward when the swirl ratio increases. It reaches the location near the ground as the swirl ratio increases to 0.87.
“Our findings can help deepen our understanding the format and structural development of tornado-like vortices, encouraging further study the effects of tornadoes on different types of structures,” says Jing.
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Contact the author: Xuhui He, School of Civil Engineering, Central South University, Changsha, Hunan 410075, China, xuhuihe@csu.edu.cn.
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Advances in Wind Engineering
Experimental study
Not applicable
Vortex characteristics of a large-scale Ward-type tornado simulator at Central South University
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Xuhui He is an Editor-in-Chief for Advances in Wind Engineering, and Haiquan Jing is an editorial board member, and they were not involved in the editorial review or the decision to publish this article.