A Lagrangian describing a gas of ideal pointlike vortices interacting with a quantum gas of spin-0 particles confined in an infinite or finite subset of R2 is derived. Singleand two-vortex dynamics is studied in the special case of a homogeneous gas in infinite and finite systems. Special attention is given to the case of the annulus (ring) for which new analytic and numerical solutions are fou...

We review the topic of quantized vortices in multicomponent Bose-Einstein condensates of dilute atomic gases, with an emphasis on that in two-component condensates. First, we review the fundamental structure, stability and dynamics of a single vortex state in a slowly rotating two-component condensates. To understand recent experimental results, we use the coupled Gross-Pitaevskii equations and...

In recent decades, many dams have been built or are under construction. Due to the high demand for water and soil erosion, increasing the need for dam construction in different regions are quite tangible. In 1900 the number of large dams, did not exceed 50. But in the 1950s to 1986 the number of large dams (over 15 meters), more than 39,000 were counted. The 70s dams has been increasing develop...

By means of electrical transport measurements we have studied the rectified motion of vortices in ratchet potentials engineered on overdamped Josephson junction arrays. The rectified voltage as a function of the vortex density shows a maximum efficiency close a matching condition to the period of the ratchet potential indicating a collective vortex motion. Vortex current reversals were detected...

The linear stability of thin vortex rings are studied by short-wavelength stability analysis. The modified Hill–Schrödinger equation for vortex rings, which incorporates curvature effect, is derived. It is used to evaluate growth rates analytically. The growth rates are also evaluated by numerical calculation and they agree well with analytical values for small e which is the ratio of core radi...

As the demand for the civil aviation has been growing for decades and the system becoming increasingly complex, the use of systems engineering and operations research tools have shown to be of further use in managing this system. In this study, we apply such tools in managing landing operations on runways (as the bottleneck and highly valuable resources of air transportation networks) to handle...

We propose very general vortex nucleation mechanismss1] analogous to a hydrodynamic instability and calculate associated critical velocity in agreement with experiments. The creation of vortices via extrinsic mechanism is driven by a formation of the surface vorticity sheet created by the ow, which reaches a critical size. Such a sheet screens an attraction of a half-vortex ring to the wall, th...

A numerical continuation method has been carried out seeking solutions for two distinct flow configurations, planar Couette flow (PCF) and laterally heated flow in a vertical slot (LHF). We found that the spanwise vortex solution in LHF identifies a new solution in PCF. The vortical structure of our new solution has the shape of a hairpin observed ubiquitously in high-Reynolds-number turbulent ...

in this paper, the flow around bluff bodies with different cross sections and determination of forces acts on them are investigated.this paper presents the results of a numerical study on the flow characteristics and heat transfer over two equal square cylinders in a tandem arrangement. spacing between the cylinders is 5 widths of the cylinder and the reynolds number ranges from 1 to 200, pr=0....

Dynamics of vortex pairs with the same and opposite circulations are studied theoretically in nonlocal nonlinear media with different intervortex separations. We demonstrate that the nonlocal nonlinear response not only leads to a dramatic suppression of the elliptical instabilities but also helps in the formation of quasi-stable rotating and breathing bound states for vortex–vortex and vortex–...