scholarly journals Resistive interchange instability criterion in anisotropic toroidal systems

1988 ◽  
Vol 31 (6) ◽  
pp. 1609 ◽  
Author(s):  
J. L. Johnson ◽  
R. J. Hastie
Keyword(s):  
Instability Criterion ◽  
Interchange Instability

To the Interchange Instability Criterion in the Magnetosphere in the Presence of Velocity Shear

2020 ◽  
Vol 125 (10) ◽  
Author(s):  
George V. Khazanov ◽  
Emanuel N. Krivorutsky ◽  
Margaret W. Chen ◽  
Colby L. Lemon
Keyword(s):  
Velocity Shear ◽  
Instability Criterion ◽  
Interchange Instability

scholarly journals Effect of interchange instability on magnetic reconnection

2013 ◽  
Vol 20 (3) ◽  
pp. 365-377 ◽  
Author(s):  
W. Lyatsky ◽  
M. L. Goldstein
Keyword(s):  
Magnetic Fields ◽  
Electric Field ◽  
Magnetic Reconnection ◽  
Plasma Flow ◽  
Buoyancy Force ◽  
Strong Turbulence ◽  
Polarization Electric Field ◽  
Interchange Instability ◽  
Reconnection Layer ◽  
Fast Reconnection

Abstract. We present here the results of a study of interacting magnetic fields that involves a force normal to the reconnection layer. In the presence of such force, the reconnection layer becomes unstable to interchange disturbances. The interchange instability results in formation of tongues of heated plasma that leaves the reconnection layer through its wide surface rather than through its narrow ends, as is the case in traditional magnetic reconnection models. This plasma flow out of the reconnection layer facilitates the removal of plasma from the layer and leads to fast reconnection. The proposed mechanism provides fast reconnection of interacting magnetic fields and does not depend on the thickness of the reconnection layer. This instability explains the strong turbulence and bidirectional streaming of plasma that is directed toward and away from the reconnection layer that is observed frequently above reconnection layers. The force normal to the reconnection layer also accelerates the removal of plasma islands appearing in the reconnection layer during turbulent reconnection. In the presence of this force normal to the reconnection layer, these islands are removed from the reconnection layer by the "buoyancy force", as happens in the case of interchange instability that arises due to the polarization electric field generated at the boundaries of the islands.

Io torus plasma transport under interchange instability and flow shears

2012 ◽  
Vol 62 (1) ◽  
pp. 41-47 ◽  
Author(s):  
Yasutaka Hiraki ◽  
Fuminori Tsuchiya ◽  
Yuto Katoh
Keyword(s):  
Plasma Transport ◽  
Interchange Instability

New Experimental Data and Analysis for Two-Phase Flow-Induced Vibration of Tube Bundles: Preliminary Results

2003 ◽  
Author(s):  
Deepanjan Mitra ◽  
Vijay K. Dhir ◽  
Ivan Catton
Keyword(s):  
Two Phase Flow ◽  
Structural Parameters ◽  
Cross Flow ◽  
Instability Criterion ◽  
Phase Flow ◽  
Flow Induced Vibration ◽  
Two Phase ◽  
Void Fractions ◽  
Comparison Of The Results ◽  
Square Array

In the past, fluid-elastic instability in two-phase flow has been largely investigated with air-water flow. In this work, new experiments are conducted in air-water cross-flow with a fully flexible 5 × 3 normal square array having pitch-to-diameter ratio of 1.4. The tubes have a diameter of 0.016 m and a length of 0.21 m. The vibrations are measured using strain gages installed on piano wires used to suspend the tubes. Experiments are carried out for void fractions from 0%–30%. A comparison of the results of the current tests with previous experiments conducted in air-water cross-flow shows that instability occurs earlier in a fully flexible array as compared to a flexible tube surrounded by rigid tubes in an array. An attempt is made to separate out the effects of structural parameters of three different experimental datasets by replotting the instability criterion by incorporating the instability constant K, in the reduced velocity parameter.

Criterion of Mechanical Instability in Inhomogeneous Atomic System

2005 ◽  
Vol 482 ◽  
pp. 127-130 ◽  
Author(s):  
Yoshitaka Umeno ◽  
Takayuki Kitamura
Keyword(s):  
Mechanical Stability ◽  
Atomic System ◽  
Instability Criterion ◽  
Fundamental Issue ◽  
Mechanical Instability ◽  
Atomic Systems ◽  
Uniform Deformation ◽  
Atomic Structures ◽  
Homogeneous Structures ◽  
Deformation Modes

The mechanical stability of a material is a fundamental issue in strength of atomic systems. Although the criterion of the mechanical stability of homogeneous structures such as perfect crystals have been successfully investigated so far, the criterion has not been able to be precisely evaluated in the cases of non-uniform deformations or bodies of inhomogeneous atomic structures. Now we present an instability criterion of an arbitrary atomic structure based on the energy balance of the whole system. This method gives the mathematically rigorous condition for the onset of an unstable deformation in any inhomogeneous atomic system. Furthermore, the method can be applied to any type of potential field, which means that ab initio evaluations of the mechanical instability of inhomogeneous structure under non-uniform deformation will be possible. The validity of the method is clarified by the application to tension of a cracked body. The onsets of unstable deformations and their deformation modes are precisely evaluated by the method.

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