scholarly journals Nonlinear dynamics of turbulence driven magnetic islands. II. Numerical simulations

2017 ◽  
Vol 24 (4) ◽  
pp. 042309 ◽  
Author(s):  
O. Agullo ◽  
M. Muraglia ◽  
S. Benkadda ◽  
A. Poyé ◽  
N. Dubuit ◽  
...  
Keyword(s):  
Nonlinear Dynamics ◽  
Numerical Simulations ◽  
Magnetic Islands

Dynamics of a Supported Cylinder in Axial Flow

2011 ◽  
Vol 99-100 ◽  
pp. 1059-1062
Author(s):  
Ji Duo Jin ◽  
Ning Li ◽  
Zhao Hong Qin
Keyword(s):  
Nonlinear Dynamics ◽  
Numerical Analysis ◽  
Numerical Simulations ◽  
Nonlinear Model ◽  
Dynamical Behavior ◽  
Axial Flow ◽  
Viscous Force ◽  
Friction Drag ◽  
Flutter Instability ◽  
Nonlinear Force

The nonlinear dynamics are studied for a supported cylinder subjected to axial flow. A nonlinear model is presented for dynamics of the cylinder supported at both ends. The nonlinear terms considered here are the quadratic viscous force and the structural nonlinear force induced by the lateral motions of the cylinder. Using two-mode discretized equation, numerical simulations are carried out for the dynamical behavior of the cylinder to explain the flutter instability found in the experiment. The results of numerical analysis show that at certain value of flow velocity the system loses stability by divergence, and the new equilibrium (the buckled configuration) becomes unstable at higher flow leading to post-divergence flutter. The effect of the friction drag coefficients on the behavior of the system is investigated.

scholarly journals Non-Extensive Statistical Analysis of Energetic Particle Flux Enhancements Caused by the Interplanetary Coronal Mass Ejection-Heliospheric Current Sheet Interaction

Entropy ◽  
2019 ◽  
Vol 21 (7) ◽  
pp. 648 ◽  
Author(s):  
Pavlos ◽  
Malandraki ◽  
Khabarova ◽  
Karakatsanis ◽  
Pavlos ◽  
...  
Keyword(s):  
Nonlinear Dynamics ◽  
Equilibrium Phase ◽  
Surrogate Data ◽  
Heliospheric Current Sheet ◽  
Diagnostic Tools ◽  
Small Scale ◽  
Magnetic Islands ◽  
Theoretical Concepts ◽  
Long Range Correlations ◽  
Interplanetary Coronal Mass Ejection

In this study we use theoretical concepts and computational-diagnostic tools of Tsallis non-extensive statistical theory (Tsallis q-triplet: qsen, qrel, qstat), complemented by other known tools of nonlinear dynamics such as Correlation Dimension and surrogate data, Hurst exponent, Flatness coefficient, and p-modeling of multifractality, in order to describe and understand Small-scale Magnetic Islands (SMIs) structures observed in Solar Wind (SW) with a typical size of ~0.01–0.001 AU at 1 AU. Specifically, we analyze ~0.5 MeV energetic ion time-intensity and magnetic field profiles observed by the STEREO A spacecraft during a rare, widely discussed event. Our analysis clearly reveals the non-extensive character of SW space plasmas during the periods of SMIs events, as well as significant physical complex phenomena in accordance with nonlinear dynamics and complexity theory. As our analysis also shows, a non-equilibrium phase transition parallel with self-organization processes, including the reduction of dimensionality and development of long-range correlations in connection with anomalous diffusion and fractional acceleration processes can be observed during SMIs events.

scholarly journals Pinning-Like Adaptive Consensus for Networked Mobile Agents with Heterogeneous Nonlinear Dynamics

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Chengjie Xu ◽  
Yanwei Wang ◽  
Hong Zhang ◽  
Xiaoqi Zhou
Keyword(s):  
Nonlinear Dynamics ◽  
Adaptive Control ◽  
Numerical Simulations ◽  
Lyapunov Stability ◽  
Mobile Agents ◽  
Pinning Control ◽  
Adaptive Strategy ◽  
Global Information ◽  
First Order ◽  
Coupling Strengths

This paper investigates the adaptive consensus for networked mobile agents with heterogeneous nonlinear dynamics. Using tools from matrix, graph, and Lyapunov stability theories, sufficient consensus conditions are obtained under adaptive control protocols for both first-order and second-order cases. We design an adaptive strategy on the coupling strengths, which can guarantee that the consensus conditions do not require any global information except a connection assumption. The obtained results are also extended to networked mobile agents with identical nonlinear dynamics via adaptive pinning control. Finally, numerical simulations are presented to illustrate the theoretical findings.

Nonlinear dynamics of the elliptic instability

2010 ◽  
Vol 646 ◽  
pp. 471-480 ◽  
Author(s):  
NATHANAËL SCHAEFFER ◽  
STÉPHANE LE DIZÈS
Keyword(s):  
Nonlinear Dynamics ◽  
Numerical Simulations ◽  
Shear Layer ◽  
Rapid Growth ◽  
Vortex Core ◽  
Nonlinear Evolution ◽  
Core Size ◽  
Layer Formation ◽  
Vortex Loop ◽  
Weakly Nonlinear

In this paper, we analyse by numerical simulations the nonlinear dynamics of the elliptic instability in the configurations of a single strained vortex and a system of two counter-rotating vortices. We show that although a weakly nonlinear regime associated with a limit cycle is possible, the nonlinear evolution far from the instability threshold is, in general, much more catastrophic for the vortex. In both configurations, we put forward some evidence of a universal nonlinear transition involving shear layer formation and vortex loop ejection, leading to a strong alteration and attenuation of the vortex, and a rapid growth of the vortex core size.

Nonlinear dynamics of feedback modulated magnetic islands in toroidal plasmas

2000 ◽  
Vol 7 (12) ◽  
pp. 4983-4995 ◽  
Author(s):  
Richard Fitzpatrick ◽  
François L. Waelbroeck
Keyword(s):  
Nonlinear Dynamics ◽  
Magnetic Islands ◽  
Toroidal Plasmas

scholarly journals Kinematical Evolution of the Pairwise Velocity Field of Galaxies

1999 ◽  
Vol 183 ◽  
pp. 265-265
Author(s):  
Naoki Seto ◽  
Jun'ichi Yokoyama
Keyword(s):  
Nonlinear Dynamics ◽  
Velocity Field ◽  
Numerical Simulations ◽  
Exponential Distribution ◽  
Relative Velocity ◽  
Statistical Distribution ◽  
Peculiar Velocity ◽  
Highly Nonlinear ◽  
Velocity Dispersions

It has been a long-standing cosmological issue to explain why the statistical distribution of the radial pairwise peculiar velocity of galaxies has an exponential shape rather than the Gaussian, as suggested by observations and explicitly shown by results of N-body simulations. Previous explanations on the exponential distribution are based on highly nonlinear dynamics of galactic systems (R < 1h–1 Mpc). That is, the exponential feature appears as a result of superposition of Gaussian velocity distributions in clumps with various velocity dispersions. Hence although this model is suitable to account for a symmetric exponential distribution with vanishing mean net relative velocity, a more elaborate treatment is necessary in order to reproduce an asymmetric exponential distribution with its peak at a negative relative velocity as observed in numerical simulations.

Numerical simulations of fast ion loss measurements induced by magnetic islands in the ASDEX Upgrade tokamak

2009 ◽  
Vol 49 (9) ◽  
pp. 095021 ◽  
Author(s):  
M. Gobbin ◽  
L. Marrelli ◽  
H.U. Fahrbach ◽  
M. Garcia-Muñoz ◽  
S. Günter ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Magnetic Islands ◽  
Fast Ion
Sign in / Sign up

Export Citation Format

Share Document