BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Measurement of the turbulent diffusivity of a magnetic field: the 
 Turbulent Angstrom Method and the Method of Oscillatory Sines - Steve Tobi
 as (University of Leeds)
DTSTART:20121126T160000Z
DTEND:20121126T170000Z
UID:TALK40652@talks.cam.ac.uk
CONTACT:Jérôme Guilet
DESCRIPTION:Determining the turbulent diffusivity of magnetic fields is on
 e of the most fundamental problems of astrophysical fluid dynamics. I shal
 l argue that a method developed by Angstrom (1861) to measure the\nthermal
  conductivity of solids can be adapted to determine the effective diffusiv
 ity of a large-scale magnetic field in a turbulent electrically conducting
  fluid. The method consists of applying an oscillatory source and measurin
 g the steady-state response. I shall initially illustrate this method in a
  two-dimensional system. This geometry is chosen because it is possible to
  compare the results with (somewhat tried and somewhat trusted) independen
 t methods that are restricted to two-dimensional flows. I shall describe t
 wo variants of this method\; one (the "Turbulent Angstrom Method") that is
  better suited to laboratory experiments the second (the "Method of Oscill
 atory Sines'') that is effective for numerical experiments. If correctly i
 mplemented\, all methods agree. I shall finish by extending the methods to
  three dimensional convective flows.
LOCATION:MR14\,  Centre for Mathematical Sciences\, Wilberforce Road\, Cam
 bridge
END:VEVENT
END:VCALENDAR