We offer a new method of reduction for a system of point vortices on a plane and a sphere. This method is similar to the classical node elimination procedure. However, as applied to the vortex dynamics, it requires substantial modification. Reduction of four vortices on a sphere is given in more detail. We also use the Poincaré surface-of-section technique to perform the reduction a four-vortex...

A vortex method model developed previously for studying the mechanisms in vortex/shear-layer interactions has been validated with large-eddy turbulence simulations by Proctor et al. (Proctor, F. H., Hinton, D. A., Han, J., Schowalter, D. G., andLin,Y. L., “Two DimensionalWake Vortex Simulations in theAtmosphere: Preliminary Sensitivity Studies,” AIAA Paper 97-0056, Jan. 1997) and eld measuremen...

Turbulent ow in a channel is simulated using a vortex method. Smoothed vortex sheets cover the near wall region while the vorticity in the remainder of the ow is contained in convecting and stretching vortex laments. The sheet elements are convected and regridded at each time step thus enabling evaluation of their wall-normal viscous diiusion and vortex stretching using nite diierences. New lam...

Vortex states in thin circular magnetic nanodots are studied using auxiliary constraining fields as a way to map out the potential energy space of a vortex, while avoiding a rigid vortex approximation. In the model, isotropic Heisenberg exchange competes with the demagnetization field caused by both surface and volume magnetization charge densities. The system energy is minimized while applying...

Sub-100 nm nanomagnets not only are technologically important, but also exhibit complex magnetization reversal behaviors as their dimensions are comparable to typical magnetic domain wall widths. Here we capture magnetic “fingerprints” of 109 Fe nanodots as they undergo a single domain to vortex state transition, using a first-order reversal curve FORC method. As the nanodot size increases from...

Within the EU AVATAR project, the added benefit of using the vortex line method is researched by calculating aero-elastic response for a variety of IEC load cases. A comparison is made to BEM to identify differences. Results are presented for yawed flow, extreme transient shear, half wake and turbulent inflow conditions. In addition to that also a dynamic pitch step case is performed including ...

The phase transition ‘‘triangular lattice–vortex liquid’’ in layered highTc superconductors in the presence of pinning centers is studied. A two-dimensional system of vortices simulating the superconducting layers in a high-Tc Shubnikov phase is calculated by the Monte Carlo method. It was found that in the presence of defects the melting of the vortex lattice proceeds in two stages: First, the...

This work is focused to study the development and control of the laminar vortex breakdown of a flow enclosed in a cylinder. We show that vortex breakdown can be controlled by the introduction of a small fixed rod in the axis of the cylinder. Our method to control the onset of vortex breakdown is simpler than those previously proposed, since it does not require any auxiliary device system. The e...