This article reviews some recent simulations of vortex sheet roll-up using the vortex blob method. In planar and axisymmetric flow, the roll-up is initially smooth but irregular small-scale features develop later in time due to the onset of chaos. A numerically generated Poincaré section shows that the vortex sheet flow resembles a chaotic Hamiltonian system with resonance bands and a heterocli...

We study the propagation properties of a single vortex in square Josephsonjunction arrays (JJA) with free boundaries and subjected to an applied dc current. We model the dynamics of the JJA by the resistively and capacitively shunted junction (RCSJ) equations. For zero Stewart-McCumber parameter βc we find that the vortex always escapes from the array when it gets to the boundary. For βc ≥ 2.5 ...

This study presents an innovative and simple way to increase the rate of heat transfer in a spiral plate heat exchanger model. Several circular cross-section rods, as continuous vortex generators, have been inserted within the spiral plate heat exchanger in the cross-stream plane. The vortex generators are located at various azimuth angles of α=30◦, 60◦, 90◦, and 120◦ with non-dimensional diame...

Introduction Conclusions References Tables Figures ◭ ◮ ◭ ◮ Back Close Full Screen / Esc Printer-friendly Version Interactive Discussion EGU Abstract Strong perturbations of the Arctic stratosphere during the winter 2002/2003 by planetary waves led to enhanced stretching and folding of the vortex. On two occasions the vortex in the lower stratosphere split into two secondary vortices that re-mer...

In two-dimensional (2D) inviscid incompressible flow, low background vorticity distribution accelerates intense vortices (clumps) to merge each other and to array in the symmetric pattern which is called “vortex crystals”; they are observed in the experiments on pure electron plasma and the simulations of Euler fluid. Vortex merger is thought to be a result of negative “temperature” introduced ...

Point vortex, first introduced by Helmholtz in 1958, is a classic model in two-dimensional incompressible fluid dynamics. The solutions to the equations of various configurations of point vortices have provided many insightful findings in various physical fields involved with vortex dynamics, such as atomic structure, large scale weather patterns and superconductors, etc (Aref 1988). One kind o...

Studies of flow behind a single cylinder have greatly contributed to our understanding of the development of complex flows like the Kármán vortex street[1] or turbulent flows. At the first instability in such a system the laminar flow (LF) becomes time dependent and vortices appear. It has been shown that this transition to the vortex shedding phase (VS) is well described by the supercritical H...

PURPOSE To further understand postoperative complications after vortex vein damage during scleral buckling surgery. METHODS The records of 34 patients (34 eyes) with vortex vein damage during scleral buckling surgery for rhegmatogenous retinal detachment were reviewed and compared with the records of 410 eyes undergoing similar surgery without vortex vein damage. RESULTS Postoperative compl...

water conveyance through pumping takes a lot of energy and cost and therefore, its application should be accompanied by exact design of pumping station as well as correct positions of pumps and their subsidiary apparatus. sumps are designed for many pumping stations and often face the problems of vortex and irregular flows. therefore an investigation of the general flow pattern in sumps in diff...

This paper aims at presenting DNS and LES as applied to the simulation of vortex wakes: in laboratory conditions (moderate to medium Reynolds numbers) and up to real aircraft conditions (high to very high Reynolds numbers). Only incompressible flows are considered. DNS and LES are able to capture complex 3-D physics provided one uses high quality numerical methods: methods with negligible numer...