This note discusses a rigorous mathematical formulation for the evolution of the Eliassen balanced vortex. It is first shown that a stable balanced vortex of finite extent can be embedded in an ambient fluid at rest, and that such a vortex exists for prescribed angular momentum and potential temperature on fluid parcels. This uses a method developed by Shutts, Booth and Norbury. This is a diffe...

This DNS study is focused on the structure of turbulence in a boundary layer. First, it is not appropriate to call the turbulent flow as a “random” motion. Any mean flow like Blasius solution, which is a Navier-Stokes solution, added by white noise or random perturbation would be rejected by Navier-Stokes equations and the perturbation will be damped quickly. The governing Navier-Stokes equatio...

The accumulative roll bonding (ARB) as a severe plastic deformation (SPD) procedure aimed at enhancing the mechanical properties of metals and alloys. In the present study, a new slab method is proposed for estimating the forming stress field for cold extrusion of metals cross the alumina interlayer powder particles by accumulative roll bonding process. Plastic deformation behavior of the metal...

the accumulative roll bonding (arb) as a severe plastic deformation (spd) procedure aimed at enhancing the mechanical properties of metals and alloys. in the present study, a new slab method is proposed for estimating the forming stress field for cold extrusion of metals cross the alumina interlayer powder particles by accumulative roll bonding process. plastic deformation behavior of the metal...

An optical vortex, produced at one point in an optical beam, would propagate through an optical system to another point where the vortex can be used for some purpose. However, asymmetrical optical elements in such a system can cause astigmatism or at least distroy the rotational symmetry of the beam, which may affect the propagation of the vortex in an undesirable way. While an optical vortex i...

Vortex rings are produced during the ejection of fluid through a nozzle or orifice, which occurs in a wide range of biological conditions such as blood flow through the valves of the heart or through arterial constrictions. Confined vortex ring dynamics, such as these, have not been previously studied despite their occurrence within the biological flow conditions mentioned. In this work, we inv...

Here we study systematically the self-focusing dynamics and collapse of vortex Airy optical beams in a Kerr medium. The collapse is suppressed compared to a non-vortex Airy beam in a Kerr medium due to the existence of vortex fields. The locations of collapse depend sensitively on the initial power, vortex order, and modulation parameters. The collapse may occur in a position where the initial ...

We consider the evolution of an isolated anticyclonic vortex encountering a continental shelf during its westward β-drift in the framework of an equivalentbarotropic model generalized to allow for the intersection of the layer interface with a sloping bottom. The approaching vortex generates both topographic coastally trapped waves, and secondary cyclonic eddies due to off-shelf advection of wa...

An ensemble of a large number of vortex lines in cylindrical bounded domain is being considered. A system of equations determining the statistical characteristics of vortex line motion is derived from the assumption that this motion is ergodic and vortex lines are sufficiently smooth. The smoothness of vortex lines is characterized by vortex diffusivity. Both cases of finite and infinite vortex...