The streamwise and transverse velocities are measured simultaneously in isotropic grid turbulence at relatively high Reynolds numbers Re(lambda) approximately 110-330. Using a conditional averaging technique, we extract typical intermittency patterns that are consistent with velocity profiles of a model for a vortex tube, i.e., Burgers vortex. The radii of the vortex tubes are several of the Ko...

We study vortex clustering in type II Superconductors. We demonstrate that the “second peak” observed in magnetisation loops may be a dynamical effect associated with a density driven instability of the vortex system. At the microscopic level the instability shows up as the clustering of individual vortices at (rare) preferential regions of the pinning potential. In the limit of quasi-static ra...

We theoretically study the creep of vortex matter in superconductors. The low temperature experimental phenomenology, previously interpreted in terms of "quantum tunneling" of vortices, is reproduced by Monte Carlo simulations of a purely "classical" vortex model. We demonstrate that a nonzero creep rate in the limit of vanishing temperature is to be expected in systems with slow relaxations as...

Vortex interactions in helicopter rotor wakes are visualized using enhanced flow visualization techniques, which in turn play a crucial role in understanding the dynamics of these complex flows. Iso-surfaces are clipped in a 3D volume to reduce visual clutter. Flow textures are improved to highlight vortical flow structure and vortex-wake interactions. These visualization techniques are applied...

Articles you may be interested in A self-consistent model for the saturation dynamics of the vortex shedding around the mean flow in the unstable cylinder wake Study of the long-time dynamics of a viscous vortex sheet with a fully adaptive nonstiff method We develop a model to numerically study the dynamics of vortex streets in channel flows. Previous work has studied the vortex wakes of specif...

In this paper, we study numerically quantized vortex dynamics and their interaction in the two-dimensional (2D) Ginzburg-Landau equation (GLE) with a dimensionless parameter ε>0 on bounded domains under either Dirichlet or homogeneous Neumann boundary condition. We begin with a review of the reduced dynamical laws for time evolution of quantized vortex centers in GLE and show how to solve these...

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An analysis of ight measurements made near a wake vortex was conducted to explore the feasibility of providing a pilot with useful wake-avoidance information. The measurements were made with relatively low-cost ow and motion sensors on a light airplane ying near the wake vortex of a turboprop airplane weighing approximately 90 000 lb. Algorithms were developed which removed the response of the ...

As an ejecta curtain advances through an atmosphere, it creates a vortex ring. By analogy with smoke rings, the curtain-driven vortex ring develops instabilities that result in waves. The number of these waves depends upon the aspect ratio of the vortex ring (i.e., the ratio of the core vortex radius to the vortex radius) and the Reynolds number (or strength) of the flow in the vortex ring. In ...