The present work is a study of the gas-flow phenomenon known as the ?end of the vortex? (EoV), which spontaneously occurs at the lower end, or under, reverse-flow centrifugal separators such as cyclones or swirl tubes. Different CFD models of swirl tubes have been built to study and analyse this phenomenon in detail. The present numerical work is based on ? and compared with ? previous experime...

Generation of well-dispersed, well-characterized fibers is important in toxicology studies. A vortex-tube shaking method is investigated using glass fibers to characterize the generated aerosol. Controlling parameters that were studied included initial batch amounts of glass fibers, preparation of the powder (e.g., preshaking), humidity, and airflow rate. Total fiber number concentrations and a...

Abstract We performed Large-eddy simulations of the flow in a model air Francis turbine range low-load regimes with swirler rotating at fixed frequency. All investigated revealed presence coherent helical vortex structure draft tube: precessing core. identified frequency this instability and obtained mean velocity fields to be utilized further works.

in this paper the effect of block shape vortex generators (vgs) on an air-water fin-tube heat exchanger has been studied experimentally using exergy analysis method. also the effect of these vgs on increasing heat transfer rate has been simulated numerically and the results show a good agreement with the experiments. in this research we used a wind tunnel to produce wind flow over heat exchange...

Steady, inviscid, axisymmetric vortex ows past a sphere are obtained numerically as solutions of a partial di erential equation for the stream function. The solutions found include vortex rings, bounded vortices attached to the sphere and in nite vortex tubes. Four families of attached vortices are described: vortex wakes behind the sphere, spherically annular vortices surrounding the spherical...

A high-order spectral difference (SD) method for solving the Navier-Stokes equations on moving, deformable unstructured grids has been developed [1]. In this paper, the SD method and the artificial compressibility method (ACM) are integrated with a dual time-stepping scheme to model unsteady incompressible viscous flow past an inline tube bundle of cylinders equally sized (diameter = d) and spa...

Color magnetic flux tubes appear in the color-flavor locked phase of high density QCD, which exhibits color superconductivity as well as superfluidity. They are non-Abelian superfluid vortices and are accompanied by orientational zero modes in the internal space associated with the color-flavor locked symmetry spontaneously broken in the presence of the vortex. We show that those zero modes are...

Abstract We propose criteria of tracking vortex surfaces in complex flows based on the vortex-surface field (VSF). The characterize accuracy and Lagrangian performance numerical VSF solution, determine time period when surface is satisfactory. Moreover, we develop a turbulent-like flow combining large-scale coherent structures Taylor–Green small-scale turbulent homogeneous isotropic turbulence ...

Varying the generator load of a hydro turbine results in short-term changes rotation frequency runner, leading inevitably to flow instability and strong swirling behind turbine. This may lead formation unsteady regimes featured by vortex known as precessing core (PVC) Dorfler et al. (2012). effect causes dangerous periodic pressure pulsations that propagate throughout water column draft tube. T...