Solutions to ideal fluid flow where the vorticity field is assumed as a sum of singular point vortices result in a Poisson system describing the motion of the vortex centres. We construct Poisson integration methods for these dynamics by splitting the Hamiltonian into its constituent vortex pair terms. From backward error analysis, the method is formally known to provide solutions to a modified...

The stability of the ordered phase of the three-dimensional XY model with random phase shifts is studied by considering the roughening of a single stretched vortex line due to disorder. It is shown that the vortex line may be described by a directed polymer Hamiltonian with an effective random potential that is long-range correlated. A Flory argument estimates the roughness exponent to z53/4 an...

Four widely-used techniques for vortex detection in turbulent flows are investigated and compared. The flow of a viscous incompressible fluid in a plane channel is simulated numerically by means of a parallel computational code based on a mixed spectral-finite difference algorithm for the numerical integration of the Navier-Stokes equations. The DNS approach (Direct Numerical Simulation) is fol...

Stratified flow past a three-dimensional obstacle such as a sphere has been a long-lasting subject of geophysical, environmental and engineering fluid dynamics. In order to investigate the effect of the stratification on the near wake, in particular, the unsteady vortex formation behind a sphere, numerical simulations of stratified flows past a sphere are conducted. The time-dependent NavierSto...

A parallel finite element micromagnetics package has been implemented, which is highly scalable, easily portable and combines different solvers for the micromagnetic equations. The implementation is based on the standard Galerkin discretization on tetrahedral meshes with linear basis functions. A static energy minimization, a dynamic time integration and the nudged elastic band method have been...

In this paper the effects of rigid triangular passive vortex generators on a  hydrofoil were investigated numerically.  In the first step using the Finite Volume Method the bare hydrofoil  were modeled and the results of lift and drag coefficients were validated using experimental data. In the next step the hydrofoil armed with vortex generators was modeled and its effect on the hydrofoil perfo...

A wind tunnel investigation was performed to study the flow field over a 70° swept sharped edge delta wing model at high angles of attack. The experiments were conducted in the subsonic wind tunnel at the Department of Mechanical Engineering, Sharif University of Technology. Velocity profiles have been measured using a special pitot tube and hot wire anemometer at angles of attacks of 10 to 35 ...