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–...

In this study, we provide a mathematical description of the onset of counter-rotating circular vortices observed for a family of slender rotating cones (of half-angles 15◦, 30◦ and 45◦) in quiescent fluid. In particular, we apply appropriate scalings and apply a change of coordinates, accounting for the effects of streamline curvature. A combined large Reynolds number and large vortex wavenumbe...

The term plasma actuator refers to an asymmetric arrangement of two electrodes (typically rectangular strips) separated by dielectric material that can be used as active flow control devices. A plasma actuator design consisting of an annular electrode array, the plasma synthetic jet actuator (PSJA), is experimentally investigated in this paper. This particular geometry creates a zero-net mass f...

Flow and scour around a vertical cylinder exposed to current are investigated by using a three-dimensional numerical model based on incompressible Reynolds-averaged Navier-Stokes equations. The model incorporates (i) k-ω turbulence closure, (ii) vortex-shedding processes, (iii) sediment transport (both bed and suspended load), as well as (iv) bed morphology. The influence of vortex shedding and...

We study both analytically and numerically the existence, uniqueness, and stability of vortex and dipole vector solitons in a saturable nonlinear medium in (2+1) dimensions. We construct perturbation series expansions for the vortex and dipole vector solitons near the bifurcation point, where the vortex and dipole components are small. We show that both solutions uniquely bifurcate from the sam...

A detailed study of the Counter-Rotating Model (CRM) for generic finite static axially symmetric thin disks with nonzero radial pressure is presented. We find a general constraint over the counter-rotating tangential velocities needed to cast the surface energy-momentum tensor of the disk as the superposition of two counter-rotating perfect fluids. We also found expressions for the energy densi...

An experimental study was conducted to investigate the effects of relative rotation direction on the wake interferences among two tandemwind turbines models. While the oncoming flow conditions were kept in constant during the experiments, turbine power outputs, wind loads acting on the turbines, and wake characteristics behind the turbines were compared quantitatively with turbine models in eit...

A detailed study of the Counter-Rotating Model (CRM) for generic electrostatic (magnetostatic) axially symmetric thin disks without radial pressure is presented. We find a general constraint over the counter-rotating tangential velocities needed to cast the surface energy-momentum tensor of the disk as the superposition of two counter-rotating charged dust fluids. We then show that this constra...

We calculate the force that pins vortices in the neutron superfluid to nuclei in the inner crust of rotating neutron stars, relying on a detailed microscopic description of both the vortex radial profile and the inner crust nuclear structure. The contribution to the pinning energy from pair condensation is estimated in the local density approximation with realistic nucleon-nucleon interactions....