Manchester Applied Mathematics and Numerical Analysis Seminars Spring 1999

June 30, 1999, 4.00 pm

Mathematics Building, Oxford Road

The screw dynamo and the current state of a dynamo experiment at Perm

Prof. Dmitri Sokoloff, Physics Dept., Moscow University

The hydromagnetic dynamo is the main process which leads to magnetic field formation in cosmic media. However, until now all attempts to reproduce this process in a laboratory have been unsuccessful, because it requires a high magnetic Reynolds number R_m, i.e. very high flow velocities. Recently, a new form of a nonstationary dynamo experiment in a braked torus-shaped container has been suggested. This experiment provides the possibility of obtaining, for a few seconds, a helical flow of liquid sodium with magnetic Reynolds number R_m of up to 100. This value can be compared with the theoretical estimate for dynamo excitation of R_m_{crit}> 17. The first experimental results obtained in Perm, Russia with a water prototype of the experimental device are reported. We will discuss properties of exciting swirling turbulent flow (Reynolds number Re of order 10^6) in the context of the dynamo experiment that is under preparation.

For further info contact either Matthias Heil (mheil@ma.man.ac.uk), Mark Muldoon (M.Muldoon@umist.ac.uk)or the seminar secretary (Tel. 0161 275 5800).