A grid free method for approximating incompressible boundary layers is introduced. The computational elements are segments of vortex sheets. The method is related to the earlier vortex method; simplicity is achieved at the cost of replacing the Navier-Stokes equations by the Prandtl boundary layer equations. A new method for generating vorticity at boundaries is also presented; it can be used w...

Vortex methods rely principally on a discretization of the continuous two-dimensional time dependent vorticity eld into a large number of vortex \blobs", whose position and strength determine the underlying velocity eld. In this paper, the convergence of the random vortex method (RVM) for a complex ow is studied in function of three discretization parameters. Two of these parameters are related...

The present study involves a novel computational technique, regarding simultaneous use of the pseudo particle method, Poisson integral method and a special-purpose computer originally designed for molecular dynamics simulations (MDGRAPE-3). In the present calculations, the dynamics of two colliding vortex rings have been studied using the vortex method. The present acceleration technique allows...

Random vortex methods are applied to the analysis of boundary layer instability in two and three space dimensions. A thorough discussion of boundary conditions is given. In two dimensions, the results are in good agreement with known facts. In three dimensions, a new version of the method is introduced, in which the computational elements are vortex segments. The numerical results afford new in...

We carry out extensive Monte Carlo simulations of the three-dimensional uniformly frustrated XY model with uncorrelated randomly perturbed couplings, as a model for the equilibrium behavior of an extreme type-II superconductor with quenched uncorrelated random point vortex pinning, in the presence of a uniform applied magnetic field. We map out the resulting phase diagram as a function of tempe...

analysis of the flow passing cylindrical obstacles is one of the basic issues in fluid dynamics and is of great importance. many surveys have been conducted to investigate the velocity field in potential and viscous flows, as a basis for finding pressure field, and investigation of forces exerted by fluid on obstacles such as uplift and drag forces in different flow regimes. since the nature of...