Kinematic-Dynamo Action Under Incompressible, Isotropic Velocity Turbulence

1971 ◽  
Vol 168 ◽  
pp. 503 ◽  
Author(s):  
I. Lerche ◽  
B. C. Low
Keyword(s):  
Dynamo Action ◽  
Kinematic Dynamo ◽  
Velocity Turbulence

scholarly journals Numerical simulations of kinematic dynamo action

2002 ◽  
Vol 397 (2) ◽  
pp. 393-399 ◽  
Author(s):  
V. Archontis ◽  
S. B. F. Dorch ◽  
Å. Nordlund
Keyword(s):  
Numerical Simulations ◽  
Dynamo Action ◽  
Kinematic Dynamo

scholarly journals Competing kinematic dynamo mechanisms in rotating convection with shear

2010 ◽  
Vol 6 (S271) ◽  
pp. 239-246 ◽  
Author(s):  
Michael R. E. Proctor ◽  
David W. Hughes
Keyword(s):  
Growth Rates ◽  
Convective Flow ◽  
Flow Fields ◽  
Velocity Shear ◽  
Dynamo Action ◽  
Preliminary Results ◽  
Rotating Convection ◽  
Kinematic Dynamo

AbstractFollowing earlier work by Hughes & Proctor (2009) on the role of velocity shear in convectively driven dynamos, we present preliminary results on the nature of dynamo action due to modified flows derived by filtration from the full convective flow. The results suggest that filtering the flow fields has surprisingly little effect on the dynamo growth rates.

scholarly journals Kinematic dynamo action in a sphere. II. Symmetry selection

2000 ◽  
Vol 456 (1999) ◽  
pp. 1669-1683 ◽  
Author(s):  
David Gubbins ◽  
C. N. Barber ◽  
S. Gibbons ◽  
J. J. Love
Keyword(s):  
Dynamo Action ◽  
Kinematic Dynamo

Kinematic dynamo action in a helical pipe

2005 ◽  
Vol 535 ◽  
pp. 347-367 ◽  
Author(s):  
L. ZABIELSKI ◽  
A. J. MESTEL
Keyword(s):  
Dynamo Action ◽  
Kinematic Dynamo ◽  
Helical Pipe

scholarly journals Influence of time dependent flows on the threshold of the kinematic dynamo action

2007 ◽  
Vol 146 (1) ◽  
pp. 313-320 ◽  
Author(s):  
A. de la Torre ◽  
J. Burguete ◽  
C. Pérez-García
Keyword(s):  
Time Dependent ◽  
Dynamo Action ◽  
Kinematic Dynamo

scholarly journals The optimal kinematic dynamo driven by steady flows in a sphere

2018 ◽  
Vol 839 ◽  
pp. 1-32 ◽  
Author(s):  
L. Chen ◽  
W. Herreman ◽  
K. Li ◽  
P. W. Livermore ◽  
J. W. Luo ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Large Scale ◽  
Helical Structure ◽  
Optimization Method ◽  
Global Optimum ◽  
Magnetic Reynolds Number ◽  
Steady Flows ◽  
Dynamo Action ◽  
Kinematic Dynamo ◽  
Scale Optimization

We present a variational optimization method that can identify the most efficient kinematic dynamo in a sphere, where efficiency is based on the value of a magnetic Reynolds number that uses enstrophy to characterize the inductive effects of the fluid flow. In this large-scale optimization, we restrict the flow to be steady and incompressible, and the boundary of the sphere to be no-slip and electrically insulating. We impose these boundary conditions using a Galerkin method in terms of specifically designed vector field bases. We solve iteratively for the flow field and the accompanying magnetic eigenfunction in order to find the minimal critical magnetic Reynolds number $Rm_{c,min}$ for the onset of a dynamo. Although nonlinear, this iteration procedure converges to a single solution and there is no evidence that this is not a global optimum. We find that $Rm_{c,min}=64.45$ is at least three times lower than that of any published example of a spherical kinematic dynamo generated by steady flows, and our optimal dynamo clearly operates above the theoretical lower bounds for dynamo action. The corresponding optimal flow has a spatially localized helical structure in the centre of the sphere, and the dominant components are invariant under rotation by $\unicode[STIX]{x03C0}$.

scholarly journals Kinematic dynamo action in square and hexagonal patterns

2013 ◽  
Vol 88 (5) ◽  
Author(s):  
B. Favier ◽  
M. R. E. Proctor
Keyword(s):  
Dynamo Action ◽  
Kinematic Dynamo
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