The unstable flow with rotating-stall-like (RS) effects in a rotor-cascade of an axialcompressor was numerically investigated. The RS was captured with the reduction in mass flow rateand increasing of exit static pressure with respect to design operating condition of the single rotor.The oscillatory velocity traces during the stall propagation showed that the RS vortices repeatperiodically, and...

Wandering is a typical feature of wing-tip vortices and it consists in random fluctuations of the vortex core. Consequently, vortices measured by static measuring techniques appear to be more diffuse than in reality, so that a correction method is needed. In the present paper statistical simulations of the wandering of a Lamb-Oseen vortex are first performed by representing the vortex core loca...

Breaking of time-reversal and point-group spatial symmetries can have a profound impact on superconductivity. One the most extraordinary effects, due to application magnetic field, is represented by Abrikosov vortices with charged supercurrents circulating around their cores. Whether similar phenomenon be obtained exploiting symmetry breaking, e.g. through electric fields or mechanical strain, ...

Two-point space–time correlation and Fourier spectrum analysis are applied to large-eddy simulation results of a compressible parallel jet flow at Reynolds number 2000 Mach 0.9. Flow properties including instantaneous vortical structures, intermittency, convection velocity pressure signals in the near flow-field presented discussed. The show multi-scale features structures after transition. Hig...

A high-resolution stereoscopic particle image velocimetry (PIV) system was used to conduct three-dimensional measurement of an air jet exhausted from a lobed nozzle. The characteristics of the mixing process in the lobed jet  ow are revealed clearly and quantitatively from the stereoscopic PIV measurement results. The instantaneous velocity and streamwise vorticity distributions revealed that ...

The recent optical transmission experiment of Karräi et al. has probed the localized quasiparticle excitations of vortices in the superconductor YBa2Cu3O7. In this paper we develop a microscopic description of single vortex dynamics, based on the Bogoliubov-deGennes equations and self-consistency through the gap equation, to determine the response of vortices to a transverse time dependent elec...

Point-vortex systems with both regular and chaotic motion can be tracked by a combination of Lagrangian observations of vortex position and of Eulerian observations of fluid velocity at a few fixed points. If only Eulerian observations are available, singularities in the tracking can develop due to nonlinearity in the observing functions on two occasions: when point vortices pass very close to ...

We capture the decay of a quantized vortex ring in superfluid helium-4 by imaging particles trapped on the vortex core. The ring shrinks in time, providing direct evidence for the dissipation of energy in the superfluid. The ring with trapped particles collapses more slowly than predicted by an available theory, but the collapse rate can be predicted correctly if the trapping of the particles o...

To construct an RG for the Coulomb gas, note that the partition for the system, eq.(VII.59), involves two parameters, (K, y0), and has an implicit cutoff, a, related to the minimum separation between vortices. As discussed earlier, the distinction between regions inside and outside the core of a vortex are arbitrary. Increasing the core size to ba modifies not only the core energy, hence y0, bu...

We present a combined analytical and numerical study of the instabilities of a pair of parallel unequal-strength vortices. We extend the analyses of a vortex in an external strain field (Crow, AIAA J. vol. 8, 1970, p. 2172; Widnall et al., J. Fluid Mech. vol. 66, 1974, p. 35) to include the orbital motion of the vortex pair. For counter-rotating pairs, the classic Crow-type periodic displacemen...