scholarly journals Bifurcation and hysteresis of the magnetospheric structure with a varying southward IMF: Field topology and global three-dimensional full particle simulations

2009 ◽  
Vol 114 (A12) ◽  
pp. n/a-n/a ◽  
Author(s):  
DongSheng Cai ◽  
Weifeng Tao ◽  
Xiaoyang Yan ◽  
Bertrand Lembege ◽  
Ken-Ichi Nishikawa
Keyword(s):  
Three Dimensional ◽  
Particle Simulations

scholarly journals How does static granular matter re-arrange for different isotropic strain rate?

2021 ◽  
Vol 249 ◽  
pp. 10001
Author(s):  
Stefan Luding
Keyword(s):  
Elastic Moduli ◽  
Large Strain ◽  
Granular Matter ◽  
Three Dimensional ◽  
Model Systems ◽  
Strain Rates ◽  
State Variables ◽  
New States ◽  
Hyper Elastic ◽  
Particle Simulations

The question of how soft granular matter, or dense amorphous systems, re-arrange their microstructure under isotropic compression and de-compression, at different strain rates, will be answered by particle simulations of frictionless model systems in a periodic three-dimensional cuboid. Starting compression below jamming, the systems experience the well known jamming transition, with characteristic evolutions of the state variables elastic energy, elastic stress, coordination number, and elastic moduli. For large strain rates, kinetic energy comes into play and the evolution is more dynamic. In contrast, at extremely slow deformation, the system relaxes to hyper-elastic states, with well-defined elastic moduli, in static equilibrium between irreversible (plastic) re-arrangement events, discrete in time. Small, finite strains explore those reversible (elastic) states, before larger strains push the system into new states, by irreversible, sudden re-arrangements of the micro-structure.

A Method of Calculating Radiative Heat Diffusion in Particle Simulations

1985 ◽  
Vol 6 (2) ◽  
pp. 207-210 ◽  
Author(s):  
L. Brookshaw
Keyword(s):  
Boundary Conditions ◽  
Radiative Heat ◽  
Three Dimensional ◽  
Heat Diffusion ◽  
New Method ◽  
Particle Simulations

AbstractA new method for solving heat diffusion in three dimensional particle simulations is described. The difficulties encounted by other authors is discussed, in particular the difficulty of including boundary conditions in particle simulations. One and three dimensional tests of the method are described.

scholarly journals Ion dynamics during compression of Mercury's magnetosphere

2010 ◽  
Vol 28 (8) ◽  
pp. 1467-1474 ◽  
Author(s):  
D. C. Delcourt ◽  
T. E. Moore ◽  
M.-C. H. Fok
Keyword(s):  
Magnetic Field ◽  
Energetic Material ◽  
Three Dimensional ◽  
Wind Pressure ◽  
Field Variation ◽  
Ion Dynamics ◽  
Ion Energization ◽  
Particle Simulations ◽  
Solar Wind Pressure ◽  
Planetary Magnetic Field

Abstract. Because of the small planetary magnetic field as well as proximity to the Sun that leads to enhanced solar wind pressure as compared to Earth, the magnetosphere of Mercury is very dynamical and at times subjected to prominent compression. We investigate the dynamics of magnetospheric ions during such compression events. Using three-dimensional single-particle simulations, we show that the electric field induced by the time varying magnetic field can lead to significant ion energization, up to several hundreds of eVs or a few keVs. This energization occurs in a nonadiabatic manner, being characterized by large enhancements of the ion magnetic moment and bunching in gyration phase. It is obtained when the ion cyclotron period is comparable to the field variation time scale. This condition for nonadiabatic heating is realized in distinct regions of space for ions with different mass-to-charge ratios. During compression of Mercury's magnetosphere, heavy ions originating from the planetary exosphere may be subjected to such an abrupt energization, leading to loading of the magnetospheric lobes with energetic material.

Coherent drift-wave structures in toroidal plasmas

1996 ◽  
Vol 56 (3) ◽  
pp. 605-613 ◽  
Author(s):  
W. Horton ◽  
T. Tajima ◽  
J.-Y. Kim ◽  
Y. Kishimoto ◽  
M. Ottaviani
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Marginal Stability ◽  
Ion Temperature ◽  
Ion Temperature Gradient ◽  
Toroidal Plasmas ◽  
Convective Structures ◽  
Drift Wave ◽  
Particle Simulations ◽  
Two Phases

Using the ion-temperature-gradient-driven drift waves as a paradigm for drift-wave anomalous transport, we explore the structure of the linear and nonlinear modes. Two phases of transport are shown to exist: (i) Bohm-like transport for parameters close to marginal stability; (ii) gyro-Bohm transport for turbulent convection cells in systems driven away from marginal stability. Nonlinear relaxation to large-scale coherent convective structures is observed in three-dimensional toroidal particle simulations.

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