Numerical Study of Tornado-Like Flow

Abstract:

A numerical computational fluid dynamics (CFD) model to simulate tornado-like vortices was proposed. The tornado-generation mechanism was similar to that of the physical generator developed at Tongji University. The feasibility of this numerical model was verified by comparing the simulation results associated with tornado-like vortices with the experimental and field observation data. Furthermore, the three wind velocity components at tangential, radial and axial directions, wind pressures, vortex radii and turbulence characteristics of tornado-like vortices at three swirl ratios were investigated. The result shows that, with the increase of swirl ratio, the maximum tangential velocity and the radius of vortex core increase when the pressure and the standard deviation of tangential velocity around the tornado-like vortex center decrease. In addition, the single tornado-like vortex gradually breaks down and develops into a double-core structure.