Suction vortices and spiral breakdown in numerical simulations of tornado-like vortices

Dual-mode spiral vortices.

We show that spiral vortices in oscillatory systems can lose stability to secondary modes to form dual-mode spiral vortices. The secondary modes grow at the vortex core where the oscillation amplitude vanishes but are nonlinearly damped by the oscillatory mode away from the core. Gradients of the oscillation phase, induced by the hosted secondary mode, can lead to additional hosting events that...

Direct Numerical Simulation of vortices

Physical Simulation of Baroclinic Waves and Vortices in the Atmosphere

The Formation and Intensification of Supercritical Tornado-like Vortices—a Laboratory Study

Observations of tornadoes in the field and laboratory investigations of tornado-like end-wall vortices have both demonstrated the complexity of this fluid phenomenon. The structure of the core region in particular depends on a number of parameters, one being the swirl ratio (S), i.e the degree of swirl in the background flow (DaviesJones, 1976), another being the degree of roughness of the unde...

End wall effects on the transitions between Taylor vortices and spiral vortices.

We present numerical simulations as well as experimental results concerning transitions between Taylor vortices and spiral vortices in the Taylor-Couette system with rigid, nonrotating lids at the cylinder ends. These transitions are performed by wavy structures appearing via a secondary bifurcation out of Taylor vortices and spirals, respectively. In the presence of these axial end walls, pure...