scholarly journals Nonlinear Theoretical Tools for Fusion-related Microturbulence: Historical Evolution, and Recent Applications to Stochastic Magnetic Fields, Zonal-flow Dynamics, and Intermittency

2009 ◽  
Author(s):  
J.A. Krommes
Keyword(s):  
Magnetic Fields ◽  
Zonal Flow ◽  
Flow Dynamics ◽  
Historical Evolution ◽  
Stochastic Magnetic Fields

scholarly journals Wave-kinetic approach to zonal-flow dynamics: Recent advances

2021 ◽  
Vol 28 (3) ◽  
pp. 032303
Author(s):  
Hongxuan Zhu ◽  
I. Y. Dodin
Keyword(s):  
Zonal Flow ◽  
Flow Dynamics ◽  
Kinetic Approach ◽  
Recent Advances

Transport in sheared stochastic magnetic fields

1997 ◽  
Vol 4 (2) ◽  
pp. 270-276 ◽  
Author(s):  
E. Vanden Eijnden ◽  
R. Balescu
Keyword(s):  
Magnetic Fields ◽  
Stochastic Magnetic Fields

Electron transport studies in stochastic magnetic fields on the Compact Auburn Torsatron

1995 ◽  
Vol 2 (6) ◽  
pp. 2026-2032 ◽  
Author(s):  
H. Lin ◽  
R. F. Gandy ◽  
S. F. Knowlton ◽  
G. J. Hartwell ◽  
D. Prichard ◽  
...  
Keyword(s):  
Electron Transport ◽  
Magnetic Fields ◽  
Transport Studies ◽  
Stochastic Magnetic Fields

scholarly journals The role of magnetic fields for planetary formation

2008 ◽  
Vol 4 (S259) ◽  
pp. 249-258 ◽  
Author(s):  
Anders Johansen
Keyword(s):  
Magnetic Fields ◽  
Turbulent Diffusion ◽  
Planet Formation ◽  
High Pressures ◽  
Mixing Time ◽  
Zonal Flow ◽  
Coherence Time ◽  
Maxwell Stress ◽  
Turbulent Diffusion Coefficient

AbstractThe role of magnetic fields for the formation of planets is reviewed. Protoplanetary disc turbulence driven by the magnetorotational instability has a huge influence on the early stages of planet formation. Small dust grains are transported both vertically and radially in the disc by turbulent diffusion, counteracting sedimentation to the mid-plane and transporting crystalline material from the hot inner disc to the outer parts. The conclusion from recent efforts to measure the turbulent diffusion coefficient of magnetorotational turbulence is that turbulent diffusion of small particles is much stronger than naively thought. Larger particles – pebbles, rocks and boulders – get trapped in long-lived high pressure regions that arise spontaneously at large scales in the turbulent flow. These gas high pressures, in geostrophic balance with a sub-Keplerian/super-Keplerian zonal flow envelope, are excited by radial fluctuations in the Maxwell stress. The coherence time of the Maxwell stress is only a few orbits, where as the correlation time of the pressure bumps is comparable to the turbulent mixing time-scale, many tens or orbits on scales much greater than one scale height. The particle overdensities contract under the combined gravity of all the particles and condense into gravitationally bound clusters of rocks and boulders. These planetesimals have masses comparable to the dwarf planet Ceres. I conclude with thoughts on future priorities in the field of planet formation in turbulent discs.

Nonlinear Magneto-Electric Response Characteristics of Giant Mag-Netostrictive-Piezoelectric Composite Sensors in Harmonic and Stochastic Excitation

2015 ◽  
Vol 764-765 ◽  
pp. 1339-1343
Author(s):  
Jia Xu ◽  
Chang Yi Hong ◽  
Zhi Wen Zhu
Keyword(s):  
Magnetic Fields ◽  
Piezoelectric Composite ◽  
Electric Response ◽  
Stochastic Excitation ◽  
Nonlinear Dynamic Model ◽  
Van Der Pol ◽  
Response Characteristics ◽  
Giant Magnetostrictive Material ◽  
Jump Phenomena ◽  
Stochastic Magnetic Fields

Nonlinear magneto-electric response characteristics of giant magnetostrictive-piezoelectric composite sensors in harmonic and stochastic magnetic fields were studied in this paper. Van der Pol nonlinear difference items were introduced to interpret the hysteresis phenomena of both giant magnetostrictive material and piezoelectric ceramics. The nonlinear dynamic model of giant magnetostrictive-piezoelectric composite sensors in harmonic and stochastic magnetic fields was developed. The expression of dynamic response of the system was obtained, and the bifurcation characteristics of the system were analyzed. The magneto-electric coefficient of the composite sensors was determined, and the effects of system parameters on the dynamic characteristics and magneto-electric coefficient of the system were analyzed. The simulation results show that there are stochastic Hopf bifurcation and jump phenomena of vibration amplitude in the system, and both of that can be avoided through adjusting parameters. The experimental results show that the system’s motion becomes chaotic when stochastic excitation is extremely large. The results of this paper are helpful for optimal design and improvement of giant magnetostrictive-piezoelectric composite sensors.

scholarly journals Eddy, drift wave and zonal flow dynamics in a linear magnetized plasma

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
H. Arakawa ◽  
S. Inagaki ◽  
M. Sasaki ◽  
Y. Kosuga ◽  
T. Kobayashi ◽  
...  
Keyword(s):  
Zonal Flow ◽  
Flow Dynamics ◽  
Magnetized Plasma ◽  
Drift Wave
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