The wavelet-based vector multiresolution technique was applied to the postprocessing of PIV results for identifying the multiscale turbulent structures of a lobed jet. By analyzing the instantaneous streamlines and vorticity fields of various scales, we obtained important information on the multiscale flow structures. The large-scale vortices or coherent structures with a central scale of a = 1...

Optical phase singularities, also called optical vortices, are known to have applications in various branches of optics. Here the role played by optical vortices in collimation testing is explained. Interference and a diffractive experimental setup in which the presence of an optical vortex permits collimation testing are presented. It is shown that the moire fringes that aid in collimation det...

We study the action and geometry of P-vortices, discriminating between the percolating and finite clusters. We also discuss the interrelation of the monopoles and P-vortices. To define P-vortices we use both the direct maximal center projection and indirect maximal center projection. We find, in particular, that the action density of the P-vortices in short clusters is substantially higher than...

The motion of self-trapped vortices on a background vorticity gradient is examined numerically and analytically. The vortices act to level the local background vorticity gradient. Conservation of momentum dictates that positive vortices (“clumps”) and negative vortices (“holes”) react oppositely: clumps move up the gradient, whereas holes move down the gradient. A linear analysis gives the traj...

The complex interactions of localized vortices with waves is investigated using a model of point vortices in the presence of a transverse or longitudinal wave. This simple model shows a rich dynamical behavior including oscillations of a dipole, splitting and merging of two like-circulation vortices, and chaos. The analytical and numerical results of this model have been found to predict under ...