The present study aimed to investigate two numerical solutions of the Navier-Stokes equations. For this purpose, the mentioned flow equations were written in two different formulations, namely (i) velocity-pressure and (ii) vorticity-stream function formulations. Solution algorithms and boundary conditions were presented for both formulations and the efficiency of each formulation was investiga...

This study examines the extent to which sea level variations at periods less than a year and spatial scales greater than 1000 km can be described by the wind-driven linear barotropic vorticity dynamics. The TOPEX/POSEIDON altimetric observations of sea level and the wind products of the National Meteorological Center are used as the database for the study. Each term of the linear bamtropic vort...

Holographic PIV is used to measure the three-dimensional velocity distribution of fully developed turbulent flow within a square duct at ReH = 1.2 × 10. The data is used for mapping the structure of the filtered, three-dimensional vorticity, strain-rate and subgrid-scale (SGS) stress tensor distributions. Visualizations of iso-vorticity surfaces show structures that are only slightly elongated,...

This work reports evidence for the existence of coherent structures in steady-state shear-flow driven plasmas in the Large Plasma Device W. Gekelman et al., Rev. Sci. Instrum. 62, 2875 1991 facility at UCLA. The measurements are performed with the vorticity probe VP , a probe that directly measures the plasma vorticity associated with the E B shear flow by means of a method that is both simpler...

Thom's vorticity condition for solving the incompressible Navier-Stokes equations is generally known as a rst-order method since the local truncation error for the value of boundary vorticity is rst order accurate. In the present paper, it is shown that convergence in the boundary vorticity is actually second order for steady problems and for time-dependent problems when t > 0. The result is pr...

In this paper we investigate the use of divergence-free wavelet bases for the Coherent Vortex Extraction (CVE) of turbulent flows. We begin with a short presentation of the construction of 3D divergence-free biorthogonal wavelets. Then we apply the CVE decomposition to a homogeneous isotropic turbulent flow, computed by a direct numerical simulation at resolution 240 and upsampled to N = 256. A...

A novel vorticity based solution methodology has been developed to compute unsteady ow, particularly separation. The vorticity of the ow is determined on a set of points and the vorticity in the eld is computed by linear interpolation. This is accomplished by the construction of a connected set of triangular elements formed by Delaunay triangularization of the points in the eld. Triangulation o...

The classical Bondi-Hoyle formula gives the accretion rate onto a point particle of a gas with a uniform density and velocity. However, the Bondi-Hoyle problem considers only gas with no net vorticity, while in a real astrophysical situation accreting gas invariably has at least a small amount of vorticity. We therefore consider the related case of accretion of gas with constant vorticity, for ...

Apparent interactions between ducted gravity waves and pre-existing mesocyclones are investigated. Preliminary analyses of WSR-88D radar observations from several cases reveal that the intersection of fine lines, whose propagation speed is consistent with that of gravity waves, and existing mesocyclones leads to an increase in rotational velocity of the mesocyclone. Utilizing simplified ducted ...

In previous investigations, the moving contact line has been reported as a significant source of vorticity. In the context of ship hydrodynamics, this subject is of significant interest as vorticity generated by the countless bubbles along a ship hull likely contribute to increased drag and wake signatures. In order to understand these phenomena better and potentially increase ship efficiency a...