Singular Behaviour of Eigenvalue Loci Arising from an MHD Instability in the Presence of Flow

1992 ◽  
pp. 237-242
Author(s):  
R. B. Paris ◽  
A. D. Wood ◽  
S. Stewart
Keyword(s):  
Mhd Instability ◽  
Singular Behaviour

A theorem on MHD-instability of plasmas with resistive walls

1971 ◽  
Vol 11 (3) ◽  
pp. 259-260 ◽  
Author(s):  
D. Pfirsch ◽  
H. Tasso
Keyword(s):  
Mhd Instability

scholarly journals Can Multi-threaded Flux Tubes in Coronal Arcades Support a Magnetohydrodynamic Avalanche?

Solar Physics ◽  
2021 ◽  
Vol 296 (8) ◽  
Author(s):  
J. Threlfall ◽  
J. Reid ◽  
A. W. Hood
Keyword(s):  
Magnetic Fields ◽  
Three Dimensional ◽  
Coronal Loops ◽  
Flux Tubes ◽  
Single Thread ◽  
Mhd Instabilities ◽  
Mhd Instability ◽  
Mhd Simulations ◽  
Ideal Mhd ◽  
Model Geometry

AbstractMagnetohydrodynamic (MHD) instabilities allow energy to be released from stressed magnetic fields, commonly modelled in cylindrical flux tubes linking parallel planes, but, more recently, also in curved arcades containing flux tubes with both footpoints in the same photospheric plane. Uncurved cylindrical flux tubes containing multiple individual threads have been shown to be capable of sustaining an MHD avalanche, whereby a single unstable thread can destabilise many. We examine the properties of multi-threaded coronal loops, wherein each thread is created by photospheric driving in a realistic, curved coronal arcade structure (with both footpoints of each thread in the same plane). We use three-dimensional MHD simulations to study the evolution of single- and multi-threaded coronal loops, which become unstable and reconnect, while varying the driving velocity of individual threads. Experiments containing a single thread destabilise in a manner indicative of an ideal MHD instability and consistent with previous examples in the literature. The introduction of additional threads modifies this picture, with aspects of the model geometry and relative driving speeds of individual threads affecting the ability of any thread to destabilise others. In both single- and multi-threaded cases, continuous driving of the remnants of disrupted threads produces secondary, aperiodic bursts of energetic release.

A New Solution of the Turbulent Near-Wake Recompression Problem

1972 ◽  
Vol 23 (2) ◽  
pp. 121-130
Author(s):  
S J Shamroth ◽  
H McDonald
Keyword(s):  
Integral Equation ◽  
Transverse Momentum ◽  
Uniqueness Condition ◽  
Two Dimensional ◽  
Interaction Theory ◽  
Initial Value ◽  
Near Wake ◽  
Singular Behaviour ◽  
Momentum Integral ◽  
Suitable Approximation

SummaryA method is presented for predicting the behaviour of a two-dimensional supersonic turbulent near-wake during the recompression process. In contrast to most previous extensions of Crocco-Lees strong interaction theory, the proposed analysis includes a transverse momentum integral equation. In addition, a modified strip method for conservation of streamwise momentum replaces the usual integral equations. Although a straightforward treatment of the equations results in the appearance of a singularity analogous to the well-known Crocco-Lees critical point, it is shown that solutions can be obtained which do not exhibit a singular behaviour, either by posing the problem as a boundary-value problem rather than an initial-value problem or by making a suitable approximation which suppresses the quasi-elliptic behaviour of the equations. Both procedures lead to an unambiguously defined uniqueness condition for the near-wake recompression solution.

Singular Behaviour of the Refractive Index in a Critical Microemulsion

1987 ◽  
Vol 4 (4) ◽  
pp. 447-452 ◽  
Author(s):  
N Rebbouh ◽  
J Buchert ◽  
J. R Lalanne
Keyword(s):  
Refractive Index ◽  
Singular Behaviour

Note on Electrolytic Polarisation

1869 ◽  
Vol 6 ◽  
pp. 579-583
Author(s):  
Tait
Keyword(s):  
Electric Resistance ◽  
Ohm’S Law ◽  
Singular Behaviour ◽  
Ohm's Law ◽  
Proper Instrument

The following note refers to some experiments instituted at the request of Mr Dewar, who asked me to determine the polarisation of the Palladium electrodes whose singular behaviour he recently described to the Society.I had just obtained one of Sir W. Thomson's most recent forms of quadrant electrometer, and it occurred to me that this must be the proper instrument for determining polarisation, as its indicacations are not affected by electric resistance, and give directly—that is, without assuming the truth of Ohm's law for reverse electromotive forces, and the consequent necessary determinations of resistance—the quantities required.

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