The quantized vortex state is investigated in a Bose-Einstein condensate, confined in a multiply connected geometry formed by a Laguerre-Gaussian optical trap. Solving the Gross-Pitaevskii equation variationally, we show that the criterion for vortex stability is that the interatomic interaction strength must exceed a critical interaction strength. The time evolution of a freely expanding Lague...

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...

We propose a numerical scheme for obtaining the stationary vortex-ring solutions of the Gross–Pitaevskii (GP) equation for an axisymmetrically trapped Bose–Einstein condensate (BEC). The effective energy functional and the associated GP equation are derived by assuming a trial phase profile for the wavefunction that is subject to the condition of circulation quantization on the rz plane. The wa...

We study vortex lattice structures of a trapped Bose-Einstein condensate in a rotating lattice potential by numerically solving the time-dependent GrossPitaevskii equation. By rotating the lattice potential, we observe the transition from the Abrikosov vortex lattice to the pinned lattice. We investigate the transition of the vortex lattice structure by changing conditions such as angular veloc...

We calculate stable arrangements for a single superfluid vortex pinned to the wall of a stationary cylindrical container. We find that, independent of the details of the pinning site, stable vortices must subtend most of the cell horizontally and cannot be vertical or nearly vertical. More generally, the geometry of a container severely limits the possible vortex configurations, making macrosco...

Abstract In order to broaden the stable working range of air-breathing continuous rotating detonation engine and explore influence combustor configuration on propagation characteristics wave, cavity-based annular is introduced. Air-breathing experiments are conducted with non-premixed ethylene air. A tri-propellant air-heater used imitate outlet parameters intake Ma4/20km. The designed mass flo...

We present results of a study of third sound in thick He films in circular resonator geometry. Frequency and line shapes of third sound resonances are measured for temperatures between 0.3 and 2.1 K in saturated films approximately 30 nm thick. From these measurements we calculate the attenuation of the sound. We find that the attenuation at a given temperature is a function of history of the f...

We show that the rotation of trapped quantum mechanical particles with a repulsive interaction can lead to vortex formation, irrespective of whether the particles are bosons or (unpaired) fermions. The exact many-particle wave function constitutes similar structures in both cases, implying that this vortex formation is indeed universal.

Gas turbine engines have a high power-to-weight ratio, making them ideal for generation of aircraft thrust, and can have excellent electrical power generation efficiencies when used in a combined cycle power plant. A complex vortical flow at the junction of the nozzle guide vane airfoil and its casing (endwall) in the turbine section tends to decrease aerodynamic efficiency and increase metal t...