Graduate School in Nonlinear Science

Sponsored by The Danish Research Agency




MIDIT                              OFD                          CATS
Modelling, Nonlinear Dynamics      Optics and Fluid Dynamics    Chaos and Turbulence Studies
and Irreversible Thermodynamics    Risø National Laboratory     Niels Bohr Institute and 
Technical University of Denmark    Building 128                 Department of Chemistry
Building 321                       P.O. Box 49                  University of Copenhagen 
DK-2800 Lyngby                     DK-4000 Roskilde             DK-2100 Copenhagen Ø
Denmark                            Denmark                      Denmark



ON THE NECESSITY OF FLOWS IN TOROIDAL MHD STEADY STATES

by By David Montgomery,
Dartmouth (U.S.A.) and,
Eindhoven University of Technology,
Netherlands

Thursday, May 31, 2001, 14.00 h
at OFD Meeting Room, Building 130, Risø National Laboratory



Abstract: Treatments of toroidal magnetohydrodynamic (MHD) confinement have almost always started from ideal MHD equilibria, via the "Grad-Shafranov Equation". If, by analogy with fluid mechanics, one insists on small but finite transport coefficients from the beginning, Ohm's law and Faraday's law are promoted to equal importance with the MHD equation of motion in determining possible steady states. The situation in a current-carrying toroid changes drastically, for largely geometrical reasons: vortical flows are required for the existence of steady states. The changes for the toroid are much greater than those for the periodic straight cylinder. However, in both geometries, values of the Hartmann number and the viscosity assume a significance that is new.