Visualization of tornado-like vortex interacting with wide tornado-break wall

A three-dimensional CFD model, based on large eddy simulation, is utilized to numerically simulate a perpendicular interaction between a traveling tornado-like vortex and a wide rigid wall. The tornado-like flow is modeled by the Rankine-Combined Vortex Model. The case, where the wall width is much larger than the tornado vortex core diameter is examined. The main goal of the paper is to improve the understanding of the dynamics of the tornado-wall interaction. The conclusions drawn in this study are supported by various visualizations. During the tornado impact, the structure of the tornado-like vortex is substantially mitigated by the wide wall. The low-level portion of the vortex is disturbed both in front of the wall and behind the wall. When the vortex is approaching the wall, the vortex-induced velocities cause a boundary layer separation from the leading face of the wall. The ejected, from the wall, vorticity patches wrap around the tornado-like vortex causing its weakening. Behind the wall the tornado vortex is subjected to the turbulent flow that further disrupts the tornado vortex structure. The tornado-like vortex mitigation results in a low wind speed region behind the tornado-break wall, where the wind velocities are reduced by more than 50 %.