A new concept of generating quasistatic magnetic fields, vortex rings, and electron jets in an isotropic homogeneous plasma is presented. The propagation of plasma waves, generated by a relativistically intense short pulse laser, is investigated by using the kinetic model and a novel nonpotential, time-dependent ponderomotive force is derived by obtaining ...

n VORTEX studied propagation of a vortex ring through a liquidgas interface in ... VORTEX successful and collected scientific data on STS-88 n This paper ...

We study theoretically the instability of countersuperflow, i.e., two counterpropagating miscible superflows, in uniform two-component Bose-Einstein condensates. Countersuperflow instability causes mutual friction between the superfluids, causing a momentum exchange between the two condensates, when the relative velocity of the counterflow exceeds a critical value. The momentum exchange leads to ...

Fishes swim by flapping their tail and other fins. Other sea creatures, such as squid and salps, eject fluid intermittently as a jet. We discuss the fluid mechanics behind these propulsion mechanisms and show that these animals produce optimal vortex rings, which give the maximum thrust for a given energy input. We show that fishes optimize both their ...

Get Away Special (GAS) payload G-093, also called VORTEX (VOrtex Ring Transit EXperiment), is an investigation of the propagation of a vortex ring through a liquid-gas interface in microgravity. This process results in the formation of one or more liquid ...

Vortex rings were produced explosively in water with enough intensity to cavitate their cores. Such cavitation limits the velocity which can be imparted to vortex rings at shallow depths. Vortex rings were produced by explosions in short cups or gun tubes...

A downdraft vortex ring in a stratified atmosphere exhibits universal attraction for nearby vertical

... The kit enables the weapon to apply flash, concussion, vortex ring impacts, marker dyes, and malodorous pulses onto a target at frequencies ...

Onsager's suggestion that a roton is a vortex ring of molecular size is discussed, and a review of experimental evidence together with theories based on this idea are presented.

... Accession Number : ADA012016. Title : The Ghost of a Vanished Vortex Ring,. Descriptive Note : Russell J. /Donnelly. Corporate ...

... Thus, the vortex ring is obvious in a lenticular cloud around a mountain, in squid's ink, in the disturbance left on the aurface of the water by an oar ...

The influence of vortex ring state (VRS) on rotorcraft flight dynamics is investigated, specifically

... Title : Experimental Observations of Vortex Ring Interaction with the Fluid Adjacent to a Surface. Descriptive Note : Interim rept.,. ...

Results are presented from an experimental investigation into the interaction of a planar shock wave with a vortex ring. A free-falling spherical soap bubble is traversed by the incident shock wave and develops into a vortex ring as a result of baroclinically deposited vorticity ({nabla?�nabla p neq 0}). The ...

The periodic formation of vortex rings in the developing region of a round jet subjected to high-amplitude acoustic forcing is investigated with High-Speed Particle Image Velocimetry. Harmonic velocity oscillations ranging from 20 to 120% of the mean exit velocity of the jet was achieved at several forcing frequencies determined by the acoustic response of ...

... Accession Number : ADD004115. Title : Vortex Flow Particle Accelerator. Descriptive Note : Patent,. Corporate Author : DEPARTMENT ...

The vortex model of the blob technique, which is one of the previously proposed vortex methods, was modified to take account of the viscous effect correctly with a simpler procedure of calculation. To examine the usefulness of the modified technique, the interaction of two vortex rings is calculated with it and two ...

We think to apply the swimming motion of a jellyfish to a micro robot made from soft material. The purpose of this study is to understand the way to propel the jellyfish's. We observed the swimming motion of the jellyfish by using a motion-capture camera, and measured the vector field of flow around the jellyfish by using a PIV system. The jellyfish is principally propelled by a ...

A comparison is made of the predictions of three different theories of quantized vortex rings and the experimental data on the deflection of such rings, containing trapped ions, by magnetic-fields. (Author)

This article addresses the fascinating 150 years history of the classical Helmholtz paper that laid the foundation of the vortex dynamics. Among general theorems on vortex motion, this memoir contains the special section on circular vortex filaments and axisymmetric vortex rings, in particular. ...

Topics studied include: 1) I have been able to determine analytically vortex rings and bubbles with swirl via the Stokes stream-function from an isoperimetric variational viewpoint extending my previous work. and 2) In the case of thin vortex rings I have...

... rotor aerodynamics; CAMRAD mathematical model; Australia. Descriptors : *VORTICES, *HOVERING, *WAKE, *HELICOPTER ROTORS, AIRFOILS ...

A steady vortex ring of prescribed strength and propagation speed can be described in terms of a Strokes stream function psi. A flux constant k measures the flow through the center of the axisymmetric vortex ring. For k = 0, Hill in 1984 found an explicit...

The proposed paper will present experimental and numerical results on the concentration fields of both reactants and products species in a reacting vortex ring that is generated from the interaction between a diffusion flame and a laminar vortex ring. Fla...

1867) and J.J. Thomson. (1883) who investigated vortex rings as candi- ...... Thompson,. J.J.. 1883. A treatise on the motion of vortex rings. London, ...

The oblique interaction of a vortex ring with a boundary in shear flow is considered by the method of three-dimensional vortex singularities (vortons). It is demonstrated how a vortex ring transforms into a horseshoe vortex. The results are in agreement with laboratory ...

Measurements made in the outer ring of the northern polar vortex from October ... decrease at the bottom of the vortex and substantial increase at the highest ...

... Title : Vortex Ring Generator: Mechanical Engineering Design for 100-kpsi Operating Pressures. Descriptive Note : Final rept. ...

... Accession Number : ADA216992. Title : The Vortex Ring Merger Problem at Infinite Reynolds Number. Corporate Author ...

... Vortex-Ring State Prediction," European Rotorcraft Forum, Moscow, September 2001. 45) Abrego, A., and Long, K., "A Wind Tunnel Investigation of ...

... of both helicopters and tiltrotors in vortex ring state. Descriptors : * HELICOPTERS, *TILT ROTOR AIRCRAFT, REAL TIME, VORTICES, AXIAL ...

... have a bearing on the use of such a configuration in fusion reaction. I 1 I )P Page 28. REFERENCES: B.! (1) 'Combustible Vortex Rings' Proc. ...

An explanation of the phenomenon of ball lightning is presented. It is suggested that the lightning ball consists of a plasma vortex ring. Aspects of the phenomenon are explained in view of the vortex ring theory. (H.M.G.)

We consider vortex rings moving in a Bose�Einstein condensate. By numerically solving the Gross�Pitaevskii equation, we show that if the circular shape of the ring is perturbed by helical Kelvin waves of given amplitude and azimuthal wave number, the translational self-induced velocity of the vortex ...

The relative motion trajectories of two arbitrary vortex rings and their interaction is investigated analytically by using two invariants of vortex rings in an ideal infinite fluid. It is shown that the system of invariants used here provides a complete picture of the mutual threading of the ...

We construct three-dimensional structures of topological defects hosted in trapped wave fields, in the form of vortex stars, vortex cages, parallel vortex lines, perpendicular vortex rings, and parallel vortex rings, and we show that the latter exist as ...

Direct Numerical Simulation is carried out to investigate the vortex dynamics of physiologic pulsatile flow in an intracranial aneurysm. The numerical solver is based on the CURVIB (curvilinear grid/immersed boundary method) approach developed by Ge and Sotiropoulos, J. Comp. Physics, 225 (2007) and is applied to simulate the blood flow in a grid with 8 million grid nodes. The ...

The temporal and spatial evolution of laminar vortex rings, that are generated in water and symmetrically cut by a thin and finite-length plate, is experimentally studied. As a result of the vortex-ring/plate interaction, five different flow cases were observed, of which two major and very distinct cases-the ...

... rings, "blocking patterns" in the atmosphere and the archetypical ... situation (say, a Gulf Stream ring or the ... work of Lord Kelvin (1880) it is known to be ...

A simple current-sheet model of a hydromagnetic shock is employed in an attempt to explain the origin of the B/sub THETA / and nu /sub poloidal/ observed previously in the hydromagnetic vortex rings produced in the conical theta pinch. Although this simple model has its limitations, it nevertheless shows clearly that the B/sub THETA / and the ...

Conditions for the steady-state existence of magnetohydrodynamic vortex structures in a dense, inviscid, incompressible fluid are derived. Within the limits imposed by these conditions, a ring structure that is compatible with vortex structure is observed in the plasmoid produced by a theta -pinch plasma gun. (T.F.H.)

The report describes a laser Doppler velocimeter (LDV) capable of performing measurements in vortex cores, presents detailed measurements of structure and stability of vortex rings and also presents measurements in the wake of a model helicopter rotor. Th...

Free wake techniques for performance prediction and optimization of hovering rotor are discussed. The influence functions due to vortex ring, vortex cylinder, and source or vortex sheets are presented. The vortex core sizes of rotor wake vortices are calc...

... (Author). Descriptors : *ION ACCELERATORS, ELECTROMAGNETS, ION BEAMS, FOCUSING, RINGS, USSR, LINEAR ACCELERATORS. ...

The main mechanism of three-dimensional turbulent flow is the stretching of vortex filaments and self-amplification of vorticity field. Stretching eventually leads to vortex reconnections and strong dissipation of energy in the areas of reconnections; which are manifestations of intermittency. An example of vortex breakdown and ...

The main mechanism of three-dimensional turbulent flow is the stretching of vortex filaments and self-amplification of vorticity field. Stretching eventually leads to vortex reconnections and strong dissipation of energy in the areas of reconnections -- which are manifestations of intermittency. An example of vortex breakdown and ...

Motion of vortex rings has been subject of theoretical and experimental studies since the time of Lord Kelvin simply because of its fundamental significance in flow physics and its practical importance in engineering applications. In this paper, we use a lattice Boltzmann method to simulate the motion of a vortex ...

Previous experiments on the interaction of a vortex ring impinging on single thin permeable screen demonstrated the formation of secondary vortices and a transmitted vortex ring. The present work concerns experimental investigation of the interaction of a vortex ring with ...

The basic equations for vortons in incompressible, inviscid fluid are derived from a pseudo-canonical formulation of three-dimensional vortex motion. The division of vortons and the reduction of meshes of time integration are taken into account. Numerical calculations based on the vorton model are made for the evolution of a connected three-ring ...

Investigation has been made of the motion of vortex rings deformed from circular shape. A theoretical calculation of their shapes on the basis of the localized induction equation for a very thin vortex filament is made and is compared with observation of distorted smoke rings produced in the laboratory, using smoke ...

Measurements of vortex-ring current created by ions in pulsed electric 10/sup -4 seconds were made in a mumber of vontex rings created is an exponential funciton of time as predicted by Donnelly and Roberts. However, the volocity dependence of ualitative agreement with the theory. (auth)

A study of the effect of external straining and shearing flows on the evolution and form of breakup of vortex rings has been performed. Two orientations each of straining and shearing flows are considered. A theoretical analysis of the ring motion for sma...

... Descriptors : *ACCELEROMETERS, FLUIDS, VORTEX GENERATORS, MANUFACTURING, AMPLIFIERS, NOISE, DYNAMICS, ACCELERATION. ...

We present the experimental discovery of compound structures comprising solitons and vortex rings in Bose-Einstein condensates. We examine both their creation via soliton-vortex collisions and their subsequent development, which is largely governed by the dynamics of interacting vortex rings. A ...

We consider finite-amplitude Kelvin waves on an inviscid vortex assuming that the vortex core has infinitesimal thickness. By numerically solving the governing Biot-Savart equation of motion, we study how the frequency of the Kelvin waves and the velocity of the perturbed ring depend on the Kelvin wave amplitude. In particular, we show ...

Vortex ring dynamics have been studied extensively in semi-infinite quiescent volumes. However, very little is known about vortex-ring formation in wall-bounded domains where vortex wall interaction will affect both the vortex ring pinch-off and propagation velocity. This ...

Models for turbulent vortex stretching are presented as differentiable fractal curve constructions with circle arcs and screw segments replacing line elements in the usual definitions of non-analytic Koch- and Peano curves. Examples of kink-free fractal curves are shown as self-intersecting, self-avoiding or (asymptotically) self-tangent loops, with flat versions partially or ...

This special section of Fluid Dynamics Research includes five articles on vortex rings in both classical and quantum fluids. The leading scientists of the field describe the trends in and the state-of-the-art development of experiments, theories and numerical simulations of vortex rings. The year 2008 was the ...

New satellite-based observations reveal that westward translating anticyclonic rings are generated as a portion of the Somali Current accelerates northward through the Socotra Passage near the mouth of the Gulf of Aden. Rings thus formed exhibit azimuthal geostrophic velocities exceeding 50 cm/s, are comparable in overall diameter to ...

wise vortices, vortex rings, trailing wingtip vortices, etc. but not the mean vortex lines in a two-dimensional shear flow. Reference 27 indicates that ...

The Yet Yawning Gulf. 10.13.08. Saturn's south polar vortex. Shadows reveal the topography of Saturn's south polar vortex. At high resolution, a new, inner ring ...

... MODELS Comprehensive codes such as CAMRAD allow the ... rotorcraft, usually allowing for two separate rotors. ... consider only the main rotor in the ...

In this paper, we use a lattice Boltzmann method to study the effect of swirl on the dynamics of an isolated three-dimensional vortex ring in a viscous incompressible fluid. We focus on a fixed Reynolds number of 800 and vary swirl magnitude and vortex core size. Results show that increasing swirl for a fixed core size or increasing ...

Relationships necessary for ring stability are derived between the self-focusing forces of an electron ring and the magnetic field gradient defocusing forces present near and just subsequent to the start of ring acceleration.

Most attempts in underwater locomotion have been focused on propeller thrust generation or recently on flapping locomotion. However, new developments in autonomous and tethered underwater vehicles motivated closer look at the biomimetics of sea animals. To this end, Cephalopoda and jelly fish utilize pulsatile jets and vortex formation for locomotion. To avoid further ...

A brief review of the current state of understanding of the vortex-ring transition in superfluid helium leads to a reexamination of the early suggestion that the critical velocity for vortex-ring creation is determined by energy and momentum conservation. The energy and impulse of a sphere and a vortex ring ...

... Title : OPERATION OF ACCELERATOR-STORAGE RING TO PROVIDE ULTRAVIOLET RADIATION. Descriptive Note : Final rept.,. ...

The time dependence of the gross properties of vortex rings have been studied in the laboratory. Four types of vortex ring have been identified: stable laminar, unstable laminar, stable turbulent and unstable turbulent rings. The stable laminar ring is a fully diffusive ...

Vortex rings with azimuthal vorticity ?r, where r is the distance from the axis of symmetry, have an unsteady contour dynamical formulation on the one hand and a family of steady solutions due to Norbury on the other hand. We consider the effect of adding swirl to such rings. Taking the swirl w r-1 maintains the contour dynamics ...

Vortex ring solutions are presented for the Landau-Lifshitz equation, which models the dynamics of a three-dimensional ferromagnet. The vortex rings propagate at constant speed along their symmetry axis and are characterized by the integer-valued Hopf charge. They are stable to axial perturbations, but it is ...

A number of experimental and numerical studies have described the collision of a laminar vortex ring with an inclined surface and noted similarities with hairpin vortices found in turbulent boundary layers. However, the dependence of the observed flow on the vortex ring properties and angles of collision have ...

... on a Slender Delta Wing Model; (b) Wing-Tip Acceleration on ... 1 Leading edge vortex above a delta wing ... visualization of leading edge vortices on 70 ...

A wind-tunnel test program was conducted on a 1:250 scale model to determine the effects of fences and vortex generators on the dispersion of LNG plumes.

Induction accelerating system similar to linear induction accelerators is considered as applied to the acceleration of electron rings. The system consists of a solenoid for preliminary acceleration, a system of pulsed power supply, an induction accelerati...

Vortex Rings Generated by a Shrouded Hartmann-Sprenger Tube AUTHOR(S): Jack Wilson REPORT DATE: July 2005. FUNDING NUMBERS: WBS-22-708-03-05. NAS3-00145 ...

Previous examinations of vortex rings impinging on porous screens has shown the reformation of the vortex ring with a lower velocity after passing through the screen, the creation of secondary vortices, and mixing. A heated screen could, in principle, alter the vortex-screen interaction by ...

Visualization of an Isolated Vortex Ring Generated from Step-Like Wind Variation and the Overshoot Phenomenon of Axial Velocity

A series of experiments on vortex rings has uncovered several unexpected results, including: (1) A formation process that is strongly Reynolds number dependent; (2) The amount of vorticity that appears downstream is very close to that predicted by a simpl...

The vortex ring is an essential and ubiquitous phenomenon that has been rather neglected in aerodynamics and technology, perhaps because it is usually construed, unfortunately, as a mere exercise in old-fashioned mathematics. The existing venerable theori...

A detailed description was made of the successive phases occuring during the evolution of vortex rings in a fluid. Theoretical conditions of stability and instability are studied in connection with variations in energy. An analogy is made with acoustical ...

It is shown that any ewuilibrium configuration or any to the stationary flow of an incompressible, perfectly conducting fluid in a magnetic field H, in the direction of the current of the fluid v. As examples, the velocity and pressure distributions are derived for the case of a ring current in magnetic field and a circular vortex. (J.S.R.)

DPIV measurements of the interaction of a vortex ring impinging on a rudimentary porous medium formed from several parallel, transparent permeable screens was made previously for screens with 49.5%, 58.95, and 84% open area ratio (?) and jet Reynolds number (Re) in the range 1000-2000. The results indicated the vortex ...

Injection of a high density plasma into a magnetic mirror was accomplished by generating plasma vortex rings under both mirror coils. Observations indicated that the rings move toward the center of the mirror and collide. Trapped magnetic fields in the ri...

The incorporation of simplified hover wake models into the comprehensive rotorcraft analysis code C A M R A D is described and examples are given on their use. The axisym metric models, in which vortices are represented by either straight lines or rings, ...

The time-dependent motion of a vortex ring obeying the Hall--Vinen equations in a superfluid He counterflow is shown to be locally stable. Both the real and imaginary parts of the normal modes of oscillation scale as wave number squared.

A laminar circular vortex ring with excellent reproducibility can be generated by pushing a mass of air through a circular orifice drilled on a buffer plate placed in front of a loudspeaker, which is driven by a stepwise voltage signal. In order to obtain...

Results are presented from an experimental study of the molecular mixing of a dynamically passive conserved scalar quantity in an axisymmetric laminar vortex ring. The experiments are based on highly resolved laser-induced fluorescence imaging measurement...

Flow visualization of the interaction of a vortex ring impinging on several parallel, transparent permeable screens was made previously for screens with 84% open area ratio. The results indicated the vortex ring split into smaller vortical structures after its interaction with the first screen and exhibited a ...

... Title : Anti-Tank Spike-Nosed Projectiles With Vortex Rings: Steady and Non- Steady Flow Simulations. Descriptive Note : Final rept. Jan 90-Jan 91. ...

Reflection processes in turbulent boundary layers were investigated by examining the reflection angle of a vortex ring. The tests were conducted in a vortex generating setup. The vortices were colored and photographed. The primary vortex transforms into a...

... ACCELERATORS, *ION ACCELERATORS, RINGS, VACUUM APPARATUS, ELECTRONS, MAGNETIC FIELDS, CROSSED FIELD DEVICES ...

A class of impulsively started, axisymmetric, laminar jets produced by a time dependent joint source

... be uniform, with J the (scaled) character- istic function ... flattening, the weaker are the sheet strengths. ... they are of identical strength and symmetrically ...

... Abstract : The stretching of a vortex ring results in sound radiation like that of a dipole (which can also be formed from a pair of monopoles), and this ...

... usually construed, unfortunately, as a mere exercise in old-fashioned mathematics. ... They are reviewed, modified and combined, and are thus made ...

... When the parachute canopies inflated fully, they exhibited good stability characteristics. (Author). Descriptors : , (*DROGUE PARACHUTES, ...

The formation process of both negatively and positively buoyant vortex rings in a piston/cylinder arrangement is investigated numerically with the aim of understanding the effect of buoyancy, characterized by a Richardson number, on the formation number. More specifically, the study focuses on how vorticity is distributed inside the ...

... The data indicate that as the instabilities develop, adjacent vortices merge and form thick vortex rings, particularly during descent. ...

... Title : Construction and Quantification of a Toroidal Bubble Apparatus. ... Abstract : A toroidal bubble is a vortex ring with a gas core in a liquid. ...

A model for vortex ring circulation developed by the author [P.S. Krueger, An over-pressure correction to the slug model for vortex ring circulation, J. Fluid Mech. 545 (2005) 427 443] is discussed. Numerical simulations of vortex ring formation are used to provide model ...

... For these reasons, a laser Doppler velocimeter (LDV) is used throughout these experiments. The LDV measures the velocity of smoke particles by ...

Many devices eject a mass of fluid either in one shot or periodically. Examples include heart valves

This talk gives a general but highly subjective overview of the expectation for accelerators and colliders for high energy physics, but not extended developments of accelerators and storage rings for application to nuclear structure physics, synchrotron r...

... One advantage of the cups is that relatively large rings are formed outside the cup lips. The following conclusions were drawn from the measured ...

... ring takes the form of a toroid, all the ... to the dovelopwmt of msoh a generator do aut ... and operation for the vortex ring generators (or attachments). ...

... entrainment lasts only a finite amount of time before the viscous forces in the medium induce ring disintegration ... place 2.3 Viscometer A ...

We study controlled methods of preparing vortex configurations in atomic Bose-Einstein condensates and their use in the studies of fundamental vortex scattering, reconnection processes, and superfluid sound emission. We explore techniques of imprinting vortex rings by means of coherently driving internal atomic ...

that the transitions from onion-to-vortex and vortex-to-reverse onion magnetic states are strongly dependent array, the transition from onion to vortex state occurs at a much lower field due to collective magnetic-called "onion" state to "vortex" state and the transition from the vortex state ...

We present an axially symmetric vortex ring dyons solutions of the SU(2) Yang-Mills-Higgs theory. These vortex rings carry electric charges that are determined by a parameter, -1<=?<=1. They possess vanishing magnetic charge and are located at a ring centered around the z-axis where the ...

We have studied oscillation of a pendulum in water using spherical bobs. By measuring the loss in potential energy, we estimate the drag coefficient on the sphere and compare to data from liquid-helium experiments. The drag coefficients compare very favorably illustrating the true scaling behavior of this phenomenon. We also studied the decay of amplitude of the pendulum over time. As observed ...

We have studied oscillation of a pendulum in water using spherical bobs. By measuring the loss in potential energy, we estimate the drag coefficient on the sphere and compare to data from liquid-helium experiments. The drag coefficients compare very favorably illustrating the true scaling behavior of this phenomenon. We also studied the decay of amplitude of the pendulum over time. As observed ...

The vortex ring is an essential and ubiquitous phenomenon that has been rather neglected in aerodynamics and technology, perhaps because it is usually construed, unfortunately, as a mere exercise in old-fashioned mathematics. The existing venerable theori...

Results of an experimental study of the directivity of noise produced by a turbulent vortex ring (Re?105) are presented. The acoustic measurements were performed in an anechoic chamber by a circular array of microphones with its center lying at the symmetry axis of the ring. A method of a synchronous processing of acoustic signals is ...

The heating and confinement of stable force-free plasma vortex structures created by theta-pinch guns are discussed. The conceptual development of vortex motion theories is reviewed, noting vorticity in MHD and plasma physics, corotational and contrarotational plasma structures, vortex rings, force-free fields, and ...

We discuss here theoretical studies of magnetic acceleration of Compact Torus plasma rings in a coaxial, rail-gun accelerator. The rings are formed using a magnetized coaxial plasma gun and are accelerated by injection of B/sub theta/ flux from an accelerator bank. After ...

We discuss here theoretical studies of magnetic acceleration of Compact Torus plasma rings in a coaxial, rail-gun accelerator. The rings are formed using a magnetized coaxial plasma gun and are accelerated by injection of B sub theta flux from an accelerator bank. After ...

This study employs classical inviscid fluid dynamics theory to investigate whether LV diastolic inflow volume and the size of the LV play a role in vortex ring formation. Fluid injection across an orifice into a large container results in the generation of a vortex ring having a constant size and speed. Relations ...

The gun consists of a cone-shaped single-turn coil energized by a low- inductance capacitor bank. A small quantity of cold gas is injected into the coil, is preionized by a separate single turn strap ringing at 400 kc, and then accelerated by the conical coil. A drift tube, which is centered in a long solenoid, acts as a guide field for the ...

Rayleigh-Taylor and Richtmyer-Meshkov instabilities arise in several high-energy fluid enviroments, including: supersonic combustion; laser (inertial confinement) fusion and supernova astrophysics. We use the ``vortex paradigm'' to guide our understanding and modeling of early-to-intermediate time phenomena at perturbed interfaces and bubbles, including reshock and ...

The topics of this volume include: (1) electron storage rings and circular accelerators, (2) accelerators and storage rings, other, (3) superconducting magnets, (4) pulsed power accelerators, (5) high intensity accelerators, (6) room temperature magnets, ...

From the author's pseudo-canonical formulation of three-dimensional vortex motion, the basic equations for the vorton model are derived. The division of vorton and reduction of meshes of time integration are assumed, in numerical calculations. This method is applied to numerical studies on evolutions of a connected 3-ring vortex and a ...

We investigate the effect of unexcitable obstacles on rotating scroll waves in three-dimensional excitable media. Our experiments use the autocatalytic Belousov-Zhabotinsky reaction and demonstrate that vortex filaments can be pinned to small, spherical obstacles. We find that single pinning sites increase the lifetime of collapsing vortex ...

The interaction between a vortex ring and a neutrally buoyant sphere centered in the axis of travel of the ring is one of the simplest fluid-structure interactions and was commented on by Lord Kelvin. A starting case in order to calculate this case is to have a laminar vortex ring interact with ...

Computational and experimental studies are conducted to investigate the influence of a trailing edge

The behavior of vortex rings generated in a stably stratified media has received only weak treatment in the literature. This configuration is believed to shed light on the basic phenomena involved in the collapse of wake in stratified fluid. The present study focused on experimental observations of the formation, the advection and the collapse of ...

ABS>A combination of two accelerators, a cyclotron and a ring-shaped accelerator which has a portion disposed tangentially to the cyclotron, is described. Means are provided to transfer particles from the cyclotron to the ring accelerator including a magnetic deflector within the ...

A study was conducted using strip theory to systematically investigate the effects of progressively more complete descriptions of the interaction of an airplane with a wake vortex system. The emphasis was in roll-dominant, parallel, vortex encounters. That is, the simulated airplane's longitudinal axis was nearly parallel to the rotation axis of the ...

High resolution DPIV measurements are made of a vortex ring formed by a piston/cylinder mechanism (Reynolds number 3700 and 7500). A complex ring structure is identified. The stopping condition of the piston leads to vortical fluid collecting near the forward stagnation point of the ring. In addition, the roll-up ...

Optical coatings applied to one-half of thin film magnetic rings allow real-time readout of the chirality of the vortex state of micro- and nanomagnetic structures by breaking the symmetry of the optical signal. We use this technique to demonstrate data storage, operation of a NOT gate that uses exchange interactions between slightly overlapping ...

We report observations on the interactions of two vortex rings generated by precision air-actuated pistons and visualized by use of the Baker PH technique in water. The relative orientation and initial velocity of the vortex rings are carefully controlled. We report detailed quantitative studies of the interaction ...

The merging of two co-axial, co-rotating vortex rings is studied experimentally. Two laminar vortex rings were generated consecutively from a piston-cylinder apparatus. The two rings propagate in the same direction and the spatial separation between them decreases until they start merging. ...

We have used a third-order essentially non-oscillatory method to obtain numerical shadowgraphs for investigation of shock-vortex interaction patterns. To search different interaction patterns, we have tested two vortex models (the composite vortex model and the Taylor vortex model) and as many as 47 parametric data ...

To study the effects of free-stream turbulence on vortex-pairing (which is known to contribute to aerodynamic noise generation and to the production of Reynolds shearing stress) in free-mixing layers, water-flume experiments were performed on the interaction between single vortex pairs and vortex rings propelled ...

Jetting swimmers, such as squid or jellyfish, propel themselves by forming axisymmetric vortex rings. In order to evaluate the performance of these swimmers, we must asses the optimality of the vortex wakes they produce, which requires an understanding of their stability. We consider the Norbury family of vortices ootnotetextJ. ...

We present diverse reconfigurable complex 3D twister vortex superlattice structures in a large area embedded with tunable vortex spirals as well as dark rings, threaded by vortex helices. We demonstrate these tunable complex chiral vortex superlattices by the superposition of relatively phase ...

The problem of three-component ring accelerator and the regime choice under the condition of light ion acceleration in a more effective way are considered. The values of the ring loading with nitrogen and hydrogen ions when a heavy component is spilled ou...

One scheme is considered, acceleration of a ring between coaxial electrodes by a B/sub theta/ field as in a coaxial rail-gun. If the electrodes are conical, a ring accelerated towards the apex of the cone undergoes self-similar compression (focussing) dur...

The loading of inductors in the KUTI-20 induction accelerating system by the electron-ion ring; the energy losses of the ring due to the excitation of the currents in the quiding magnetic field coils and deceleration of the ring by image charges during it...

The influence upon axial stability in an electron ring of the diffraction radiation reaction force, generated by a ring moving in an acceleration column, is calculated theoretically. A stability criterion is obtained, and numerical examples show that the criterion is not an important constraint upon the choice of parameters or the ...

Fishes have an enormous diversity of body shapes and fin morphologies. From a hydrodynamic standpoint, the functional significance of this diversity is poorly understood, largely because the three-dimensional flow around swimming fish is almost completely unknown. Fully three-dimensional volumetric flow measurements are not currently feasible, but measurements in multiple transverse planes along ...

This chapter is an attempt to attain a new and profound model of the nature's structure using a vortex-ring-fractal theory (VRFT). Scientists have been trying to explain some phenomena in Nature that have not been explained so far. The aim of this paper is the vortex-ring-fractal modeling of elements in the Mendeleev's periodic table, ...

This chapter is an attempt to attain a new and profound model of the nature's structure using a vortex-ring-fractal theory (VRFT). Scientists have been trying to explain some phenomena in Nature that have not been explained so far. The aim of this paper is the vortex-ring-fractal modeling of elements in the Mendeleev's periodic table, which is not in ...

. It is striking to notice that his friend William Thomson (ennobled as Lord Kelvin) was at the same epoch closed on themselves (e.g. a vortex ring) or end on a boundary. He also mentioned the `remarkable analogy vortex tubes, and two vortex rings, for which he explained how they pass ...

We demonstrate the stability of a stationary vortex breather with vorticity S=2 in the two-dimensional discrete nonlinear Schroedinger model for a square lattice and also discuss the effects of exciting internal sites in a vortex ring. We also point out the fundamental difficulties of observing these solutions with current experimental ...

With a Biot-Savart model of vortex filaments to provide initial conditions, a finite difference scheme for the incompressible Navier-Stokes equation is used in the region of closest approach of two vortex rings. In the Navier-Stokes solution, we see that the low pressure which develops between the interacting vorticity regions causes ...

the large vortex ring formed by the combined tip vortices. (b)Sketch of the flow over the wing during vorticity into the tip vortex. #12;The Weis-Fogh mechunism of lift generation 57 it moves downwards as the wing to join up with the corresponding vortex on the other wing to create an outer `tip' ...

The laminar flow in a vortex is primarily determined by the toroidal laminar vortex core, the ondulatory flow by the ondulated laminar core, and the turbulent flow by the turbulent oscillating core. Inside these three global vortex flows, locally or globa...

In an earlier publication we considered acceleration of plasma rings (Compact Torus). Several possible accelerator configurations were suggested and the possibility of focusing the accelerated rings was discussed. In this paper we consider one scheme, acceleration of a ...