We present a natural framework for studying the persistence problem in two-dimensional fluid turbulence by using the Okubo-Weiss parameter Λ to distinguish between vortical and extensional regions. We then use a direct numerical simulation of the two-dimensional, incompressible Navier-Stokes equation with Ekman friction to study probability distribution functions (PDFs) of the persistence times...

Quantum anomalies give rise to new transport phenomena. In particular, a magnetic field can induce an anomalous current via the chiral magnetic effect and a vortex in the relativistic fluid can also induce a current via the chiral vortical effect. The related transport coefficients can be calculated via Kubo formulas. We evaluate the Kubo formula for the anomalous vortical conductivity at weak ...

Direct numerical simulation (DNS) of a turbulent boundary layer (TBL) subjected to adverse pressure gradient (APG) at Reτ = 834 is performed to investigate large-scale influences on vortical motions. For comparison, DNS data of a zero pressure gradient (ZPG) TBL at Reτ = 837 is analyzed. The spanwise energy spectra of the streamwise velocity fluctuations show that the large-scale energy above 4...

Axisymmetric vortices with high level of axial vorticity are considered. Consistency conditions result in so-called compensating regime of the vortical flow. The power laws associated with this regime are applied to a series of vortices of different scales: bathtub vortex, tornadoes and tropical cyclones. Key–Words: vortical flows, bathtub vortex, tornado, tropical cyclone

Abstract Gluon interaction introduces remarkable corrections to the magnetic polarization effects on chiral fermions, which is known as inverse catalysis. It a natural speculation that vorticity, has many similar properties field, would bring non-negligible contribution rotational suppression. Using an intuitive semi-classical background field method we studied rotation dependence of effective ...

AIM To investigate atrial flow patterns in the normal adult heart, to explore whether caval vein arrangement and patency of the foramen ovale (PFO) may be associated with flow pattern. MATERIALS AND METHODS Time-resolved, three-dimensional velocity encoded magnetic resonance imaging (4D flow) was employed to assess atrial flow patterns in thirteen healthy subjects (6 male, 40 years, range 25-...

This report presents results of systematic experimental studies of various passive mitigation techniques to reduce aero-optical effects caused be turbulent boundary layers. Parametric studies of Large-Eddy BreakUp devices showed that aero-optical distortions can be suppressed by 45% for several boundary layer thicknesses. It was shown that moderate cooling of the wall also reduces aero-optical ...

The dynamics and dispersion of nonevaporating droplets in a forced transitional shear layer are studied. The shear layer is formed by two coflowing parallel streams downstream of a splitter plate. The effects of periodic forcing on the dynamics of large-scale vortical structures and on the dispersion characteristics of droplets in a spatially and temporally developing shear layer are investigat...