Simulating tornado-like flows: the effect of the simulator’s geometry

Abstract

Within the wind engineering community, a series of physical simulators of differing geometries have been used to investigate the flow-field of tornado-like vortices. This paper examines the influence that the geometry of a simulator can have on the generated flow field. Surface pressure and velocity data have been measured for two swirl ratios (S = 0.30 and S = 0.69) in two different simulators of different scale and varying geometry. The results of this research suggest that far from being a mature research field, there are still many unresolved questions that need to be addressed before data obtained from such simulators can be used with confidence in practice.

Numerical study of debris flight in a tornado-like vortex

“…Further, the flight characteristics of debris were assumed with no rotation, which might be considered less realistic in a highly swirling vortex flow field when the rotation of debris generates lift, which would lead to a different interaction between the fluid and debris. It is also worth noting that this work has simulated the flow assuming one single definition of aspect ratio, but as indicated by Gillmeier et al (2019) and Gairola and Bitsuamlak (2019), this may be an important area which has hitherto largely been neglected. Notwithstanding this, this research shows the flight behaviour of different debris groups and their corresponding impact range and thus enables the potential dangers associated with flying debris in tornadoes to be evaluated.…”

“…The authors are incredibly comforted by the fact that the reviewer has raised this point since it proves that others are starting to appreciate this fact as well. For the last few years this is an issue that we have also been raising at many international conferences, is what Gillmeier based her PhD thesis on and is formally stated in a peer review journal (Gillmeier et al 2019 …which would lead to a different interaction between the fluid and debris. It is also worth noting that this work has simulated the flow assuming one single definition of aspect ratio, but as indicated by Gillmeier et al (2019) and Gairola and Bitsuamlak (2019), this may be an important area which has hitherto largely been neglected.…”

A Study of the Effects of Tornado Translation on Wind Loading Using a Potential Flow Model

“…The study proposed that the radial momentum flux is one of the primary parameters sustaining the vortex flow structure and showed the reproduction of vortex evolution by adjusting the angular momentum. Following this, extensive studies using analytical models (Harlow and Stein, 1974;Jischke and Parang, 1974;Baker and Church, 1979;Rotunno 1979;Fiedler and Rotunno, 1986) and physical tornado simulators (Wan and Chang, 1972;Church et al, 1979;Mitsuta and Monji, 1984;Monji, 1985;Haan et al, 2008;Matsui and Tamura, 2009;Hashemi Tari et al, 2010;Refan et al, 2014;Gillmeier et al, 2017;Refan and Hangan, 2018;Ashton et al, 2019;Gillmeier et al, 2019;Ashrafi et al, 2021) as well as numerical simulators (Ishihara et al, 2011;Ishihara and Liu, 2014;Eguchi et al, 2018;Yuan et al, 2019;Gairola and Bitsuamlak, 2019;Kashefizadeh et al, 2019;Kawaguchi et al, 2019;Li et al, 2020) had been conducted in order to study the flow fields of tornado-like vortices. However, due to various constraints, these simulators cannot facilitate comprehensive study of vortex translation.…”

Performance-based wind engineering framework for vertical structures subjected to nonstationary wind loads

“…1.6). The consideration of these ratios is particularly important for precise replication of tornadoes with wind tunnel experimentation (Davies-Jones et al, 2001;Gillmeier et al, 2019) and for accurate modeling of the induced fluctuating wind forces Refan and Hangan, 2018). Like the downburst, tornadoes travel along a path, and the time of nonsynoptic, nonstationary wind loading (which may fluctuate significantly due to vortex wandering relevant to structures typically lasts for only a few minutes.…”