Numerical calculation on Vortex Breakdown in Rotating System

Numerical Simulation of Vortex Breakdown by the Vortex-Filament Method

Impact of rotating and fixed nozzles on vortex breakdown in compressible swirling jet flows

Vortex breakdown of swirling, round jet flows is investigated in the compressible, subsonic regime by means of Direct Numerical Simulation (DNS). This is achieved by solving the compressible Navier–Stokes equations on a cylindrical grid using high-order spatial and temporal discretization schemes. The Reynolds number is Re = ρ c w ◦ c R ◦/μ◦c = 5000 and the flow is moderately compressible with ...

Giant vortex and the breakdown of pinning in a rotating Bose–Einstein condensate

This talk presents work in collaboration withA. Aftalion (Paris-6) and Lia Bronsard (McMaster). We consider the following variational problem arising from a two-dimensional model for rotating Bose–Einstein Condensates (BEC.) Let a = a(r) be a real-analytic radially symmetric function in the plane, with the property that A = {x ∈ R : a(|x|) > 0} is an annulus, and such that a vanishes linearly a...

On the phenomenon of vortex street breakdown

A von Karman vortex street generated in the usual way was subjected to a deceleration, thereby changing the ratio of longitudinal to lateral spacing between the vortices. Distortion of the individual vortices followed which resulted in annihilation of concentrated vortex regions and creation of a stationary wake flow. This wake flow was itself dynamically unstable and developed into a new vorte...

The sensitivity of steady vortex breakdown bubbles in confined cylinder flows to rotating lid misalignment

Recent experimental observations using tracer visualization techniques have suggested that even for low Reynolds number flows, the steady vortex breakdown bubble in a torsionally driven cylinder is not axisymmetric and has an inflow/outflow asymmetry at its tail. These results seem to suggest that this type of vortex breakdown is closer in structure to that observed in the open vortex tube than...