scholarly journals Toroidal Field Reversals

2010 ◽  
Vol 6 (S271) ◽  
pp. 62-68
Author(s):  
T. M. Rogers
Keyword(s):  
Numerical Simulations ◽  
Differential Rotation ◽  
Convection Zone ◽  
Solar Interior ◽  
Toroidal Field ◽  
Poloidal Field ◽  
Mhd Simulations

AbstractI present axisymmetric numerical simulations of the solar interior, with differential rotation imposed in the convection zone and tachocline and a dipolar poloidal field confined to the radiative interior. In these simulations toroidal field reversals which are equator-ward propagating are driven in the absence of a dynamo. These reversals are driven in the tachocline and are seen at the top of the convection zone. While not solar-like in many ways, these reversals do show some solar-like properties not previously seen in full MHD simulations.

scholarly journals High Resolution 3D Relativistic MHD Simulations of Jets

2009 ◽  
Vol 5 (H15) ◽  
pp. 254-255
Author(s):  
A. Ferrari ◽  
A. Mignone ◽  
P. Rossi ◽  
G. Bodo ◽  
S. Massaglia
Keyword(s):  
Magnetic Field ◽  
High Resolution ◽  
Numerical Simulations ◽  
Three Dimensional ◽  
Full Length ◽  
Toroidal Field ◽  
Toroidal Magnetic Field ◽  
Mhd Simulations ◽  
Strong Current

AbstractWe performed high-resolution three dimensional numerical simulations of relativistic MHD jets carrying an initially toroidal magnetic field responsible for the process of jet acceleration and collimation. We find that in the 3D case the toroidal field gives rise to strong current driven kink instabilities leading to jet wiggling. However, it appears to be able to maintain an highly relativistic spine along its full length.

A Behavioural Model of the Solar Magnetic Cycle

2017 ◽  
Vol 13 (S335) ◽  
pp. 94-97
Author(s):  
Milton Munroe
Keyword(s):  
Magnetic Field ◽  
Conceptual Model ◽  
Differential Rotation ◽  
Toroidal Field ◽  
Solar Dynamo ◽  
The Sun ◽  
Poloidal Field ◽  
Magnetic Cycle ◽  
Poloidal Magnetic Field ◽  
Solar Magnetic Cycle

All recent models of solar magnetic cycle behaviour assume that the Ω-effect stretches an existing poloidal magnetic field into a toroidal field using differential rotation (Featherstone and Miesch 2015). The α-effect recycles the toroidal field back to a poloidal field by convection and rotation and this is repeated throughout the cycle. Computer simulations based on that conceptual model still leave many questions unanswered. It has not resolved where the solar dynamo is located, what it is or what causes the differential rotation which it takes for granted. Does this paradigm need changing? The conceptual model presented here examines the sun in horizontal sections, analyses its internal structure, presents new characterizations for the solar wind and structures found and shows how their interaction creates rotation, differential rotation, the solar dynamo and the magnetic cycle.

scholarly journals Magnetic confinement of the solar tachocline: influence of turbulent convective motions

2010 ◽  
Vol 6 (S271) ◽  
pp. 399-400
Author(s):  
Antoine Strugarek ◽  
Allan Sacha Brun ◽  
Jean-Paul Zahn
Keyword(s):  
Convection Zone ◽  
Magnetic Coupling ◽  
Magnetic Confinement ◽  
Convective Zone ◽  
Solar Interior ◽  
The Sun ◽  
Poloidal Field ◽  
Convective Motions ◽  
Radiation Zone ◽  
Field Lines

AbstractWe present the results of 3D simulations, performed with the ASH code, of the nonlinear, magnetic coupling between the convective and radiative zones in the Sun, through the tachocline. Contrary to the predictions of Gough & McIntyre (1998), a fossil magnetic field, deeply buried initially in the solar interior, will penetrate into the convection zone. According to Ferraro's law of iso-rotation, the differential rotation of the convective zone will thus expand into the radiation zone, along the field lines of the poloidal field.

scholarly journals Origin of solar magnetism

2010 ◽  
Vol 6 (S273) ◽  
pp. 28-36 ◽  
Author(s):  
Arnab Rai Choudhuri
Keyword(s):  
Solar Cycle ◽  
Differential Rotation ◽  
Convection Zone ◽  
Meridional Circulation ◽  
Solar Surface ◽  
Dynamo Model ◽  
Solar Cycles ◽  
Poloidal Field ◽  
Flux Transport ◽  
Solar Magnetism

AbstractThe most promising model for explaining the origin of solar magnetism is the flux transport dynamo model, in which the toroidal field is produced by differential rotation in the tachocline, the poloidal field is produced by the Babcock–Leighton mechanism at the solar surface and the meridional circulation plays a crucial role. After discussing how this model explains the regular periodic features of the solar cycle, we come to the questions of what causes irregularities of solar cycles and whether we can predict future cycles. Only if the diffusivity within the convection zone is sufficiently high, the polar field at the sunspot minimum is correlated with strength of the next cycle. This is in conformity with the limited available observational data.

Preliminary Research of Manufacturing Technology for ITER Magnet Supports

2012 ◽  
Vol 249-250 ◽  
pp. 466-471
Author(s):  
Bing Lin Hou ◽  
Peng Yuan Li ◽  
Shu Juan Yang ◽  
Chuan Jie Pan
Keyword(s):  
Reliable Method ◽  
Manufacturing Technology ◽  
Total Weight ◽  
Toroidal Field ◽  
Poloidal Field ◽  
Full Size ◽  
Safety Requirements ◽  
The Core ◽  
Preliminary Research ◽  
Working Procedure

The International Thermal Experiment Reactor (ITER) is designed to operate for 20 years with high safety requirements. The magnets with their total weight being about 10,000t sit at the core of the ITER machine. In order to guarantee the safety of the ITER machine, the research of the manufacturing technology for ITER magnet supports (MS) is an indispensable working procedure before the MS are produced. The MS consist of toroidal field (TF) gravity supports (GS), poloidal field (PF) supports and correction coils (CC) supports. This paper summarizes that the preliminary research results for the manufacturing of the GS with thermal anchor, the reliable method to manufacture the U-shaped clamp with tapered slots for PF coil supports and the special devices for test of full-size fasteners used in all the MS.

scholarly journals Simulations of Core Convection Dynamos in Rotating A-type Stars

2004 ◽  
Vol 215 ◽  
pp. 376-377
Author(s):  
Matthew Browning ◽  
Allan Sacha Brun ◽  
Juri Toomre
Keyword(s):  
Magnetic Field ◽  
Numerical Simulations ◽  
Differential Rotation ◽  
Three Dimensional ◽  
Dynamo Action ◽  
The Core ◽  
Core Convection ◽  
Seed Field ◽  
Initial Seed ◽  
Three Dimensional Simulations

We have conducted preliminary numerical simulations of a core convection dynamo operating within an A-type star of two solar masses. Convection within the core clearly can admit magnetic dynamo action. Magnetic field strengths in our three-dimensional simulations grow by many orders of magnitude, from an initial seed field to kilo-Gauss levels. We discuss the differential rotation and magnetic field sustained in our simulations.

scholarly journals Numerical Simulations of 3D Compressible Convection

1993 ◽  
Vol 137 ◽  
pp. 296-299
Author(s):  
Herbert J. Muthsam ◽  
Johann Zöchling
Keyword(s):  
Numerical Simulations ◽  
Convection Zone ◽  
Numerical Models

AbstractNumerical models of a convection zone embedded between two stable layers have been calculated; one is shortly presented and in particular a few items concerning the lower overshoot region are discussed.

Sign in / Sign up

Export Citation Format

Share Document