The interaction of gas bubbles with a vortex is investigated experimentally to clarify the role of the initial bubble position on its trajectory around the tip vortex shed from a large hydrofoil. The experiments performed with 4-6mm bubbles show that the bubbles can undergo no capture, quick capture into the tip vortex or slow capture with a spiral trajectory around the vortex.

We reveal that spatially localized vortex solitons become stable in self-focusing nonlinear media when the vortex symmetry-breaking azimuthal instability is eliminated by a nonlocal nonlinear response. We study the main properties of different types of vortex beams and discuss the physical mechanism of the vortex stabilization in spatially nonlocal nonlinear media.

The two-dimensional ~2-D! merging of an intense, pointlike vortex with a diffuse, extended vortex is investigated with experiments using strongly magnetized electron columns in a Malmberg– Penning trap, and with numerical simulations using a 2-D particle-in-cell code. The study is restricted to highly nonlinear conditions, where the perturbative approach does not apply. A very good agreement be...

We discuss the elementary vortex pinning in type-II superconductors in connection with the Anderson’s theorem for nonmagnetic impurities. We address the following two issues. One is an enhancement of the vortex pinning energy in the unconventional superconductors. This enhancement comes from the pair-breaking effect of a nonmagnetic defect as the pinning center far away from the vortex core (i....

Amagnetic nanoparticle in a vortex state is a promising candidate for the information storage. One bit of information corresponds to the upward or downward magnetization of the vortex core (vortex polarity). The dynamics of the magnetic vortex driven by a spin current is studied theoretically. Using a simple analytical model and numerical simulations, we show that a nondecaying vortex motion ca...

In this study the augmentation of heat transfer in a rectangular channel with triangular vortex generators is evaluated. The span wise averaged Nusselt number, mean temperature and total heat flux are compared with and without vortex generators in the channel at a blade angle of 30° for Reynolds numbers 800, 1200, 1600, and 2000. The use of vortex generators increases the span wise averaged Nus...

This article reviews some recent simulations of vortex sheet roll-up using the vortex blob method. In planar and axisymmetric flow, the roll-up is initially smooth but irregular small-scale features develop later in time due to the onset of chaos. A numerically generated Poincaré section shows that the vortex sheet flow resembles a chaotic Hamiltonian system with resonance bands and a heterocli...

We study the propagation properties of a single vortex in square Josephsonjunction arrays (JJA) with free boundaries and subjected to an applied dc current. We model the dynamics of the JJA by the resistively and capacitively shunted junction (RCSJ) equations. For zero Stewart-McCumber parameter βc we find that the vortex always escapes from the array when it gets to the boundary. For βc ≥ 2.5 ...

This study presents an innovative and simple way to increase the rate of heat transfer in a spiral plate heat exchanger model. Several circular cross-section rods, as continuous vortex generators, have been inserted within the spiral plate heat exchanger in the cross-stream plane. The vortex generators are located at various azimuth angles of α=30◦, 60◦, 90◦, and 120◦ with non-dimensional diame...

Introduction Conclusions References Tables Figures ◭ ◮ ◭ ◮ Back Close Full Screen / Esc Printer-friendly Version Interactive Discussion EGU Abstract Strong perturbations of the Arctic stratosphere during the winter 2002/2003 by planetary waves led to enhanced stretching and folding of the vortex. On two occasions the vortex in the lower stratosphere split into two secondary vortices that re-mer...