Classical and quantum theory of spin waves in the vortex state of a mesoscopic submicron magnetic disk have been developed with account of the finite mass density of the vortex. Oscillations of the vortex core resemble oscillations of a charged string in a potential well in the presence of the magnetic field. A conventional gyrotropic frequency appears as a gap in the spectrum of spin waves of ...

We study the two transverse quadrupole modes of a cigar-shaped Bose-Einstein condensate with a single centered vortex. We show that the counterrotating mode is more strongly damped than in the absence of a vortex, whereas the corotating mode is not affected appreciably by the vortex. We interpret this result as a decay of the counterrotating quadrupole mode into two excitations of the vortex li...

The vortex-vortex and vortex-antivortex correlation functions are determined for the two-dimensional O(2) model undergoing phase ordering. We find reasonably good agreement with simulation results for the vortex-vortex correlation function where there is a short-scaled distance depletion zone due to the repulsion of like-signed vortices. The vortex-antivortex correlation function agrees well wi...

The article is devoted to the development of software for calculating the hydrodynamic conditions and kinetic characteristics of granulation process in vortex devices. In the basis software Vortex Granulator© and Classification in vortex flow original mathematical model for calculating the flow rate of gas and granules classification and separation processes of granules in a vortex granulator, ...

The transition to turbulence in boundary flow of superfluid 4He is investigated using a vibrating wire. An object in a superfluid is usually accompanied by remanent vortices, enabling to cause turbulence by its oscillation even at very low temperature. However, remanent vortices make it difficult to investigate the transition to turbulence. Recently, we have successfully devised a condition of ...

The dynamics of vortex lattices in stirred Bose-Einstein condensates have been studied at finite temperatures. The decay of the vortex lattice was observed nondestructively by monitoring the centrifugal distortions of the rotating condensate. The formation of the vortex lattice could be deduced from the increasing contrast of the vortex cores observed in ballistic expansion. In contrast to the ...

For a strictly inviscid barotropic flow with conservative body forces, the Helmholtz vorticity theorem shows that material or Lagrangian surfaces which are vortex surfaces at time t =0 remain so for t > 0. In this study, a systematic methodology is developed for constructing smooth scalar fields φ(x, y, z, t =0) for Taylor–Green and Kida– Pelz velocity fields, which, at t =0, satisfy ω · ∇φ=0. ...

We study discrete vortices in coupled discrete nonlinear Schrödinger equations. We focus on the vortex cross configuration that has been experimentally observed in pho-torefractive crystals. Stability of the single-component vortex cross in the anti-continuum limit of small coupling between lattice nodes is proved. In the vector case, we consider two coupled configurations of vortex crosses, na...

We consider the nonlinear dynamics of a single vortex in a superconductor in a strong rf magnetic field B0 sin t. Using the London theory, we calculate the dissipated power Q B0 , and the transient time scales of vortex motion. For the linear Bardeen-Stephen viscous drag force, vortex velocities reach unphysically high values during vortex penetration through the oscillating surface barrier. It...

the steger and warming flux vector splitting implicit scheme is used to numerically solve two dimensional reynolds averaged navier–stokes (rans) equations governing the vortex induced vibration of a flexible riser laterally supported by a spring and a damper. the k–ε model is used as turbulence model to simulate the turbulent flow in the wake of the riser. to update the new position of the rise...