English

Energy transfers in dynamos with small magnetic Prandtl numbers

Fluid Dynamics 2015-06-26 v2 Plasma Physics

Abstract

We perform numerical simulation of dynamo with magnetic Prandtl number Pm=0.2\mathrm{Pm} =0.2 on 102431024^3 grid, and compute the energy fluxes and the shell-to-shell energy transfers. These computations indicate that the magnetic energy growth takes place mainly due to the energy transfers from large-scale velocity field to large-scale magnetic field and that the magnetic energy flux is forward. The steady-state magnetic energy is much smaller than the kinetic energy, rather than equipartition; this is because the magnetic Reynolds number is near the dynamo transition regime. We also contrast our results with those for dynamo with Pm=20\mathrm{Pm} =20 and decaying dynamo.

Keywords

Cite

@article{arxiv.1407.6855,
  title  = {Energy transfers in dynamos with small magnetic Prandtl numbers},
  author = {Rohit Kumar and Mahendra K. Verma and Ravi Samtaney},
  journal= {arXiv preprint arXiv:1407.6855},
  year   = {2015}
}

Comments

20 pages, 16 figures