Kinematic-Dynamo Action Under Incompressible, Isotropic Velocity Turbulence
Abstract
We demonstrate that incompressible, isotropic velocity turbulence on its own iii an infinite medium leads to regenerative dynamo action. Earlier work has demonstrated that (i) incompressible velocity turbulence possessing a net helicity generates dynamo action in an infinite medium; (ii) isotropic, compressible velocity turbulence generates dynamo action in an infinite medium. The present results show first that regenerative dynamo action is not peculiar to the assumption of either nonisotropy or compressibility, and second that the turbulent Lorentz force (which is never isotropic no matter whether the velocity turbulence is isotropic or not) is the main cause of purely turbulent dynamo action. The fact that incompressible, isotropic turbulence generates dynamo activity just underscores these facts.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- September 1971
- DOI:
- 10.1086/151104
- Bibcode:
- 1971ApJ...168..503L