(Color online) Schematic drawing of the liquid-metal vessel and a photograph of the set-up.
(Color online) A pulse of electrical current (black curve) in the emitting coil generates an Alfvén wave. The associated change in magnetic flux is recorded at the opposite end in the top coil, Tc.
(Color online) Same as Fig. 2 on the left hand side, except time has been made dimensionless using the propagation time of Alfvén waves and EMF has been made dimensionless using Lu(nI)/(σL). On the right hand side, the same pulses computed numerically.
(Color online) Response to a sweep in the emitting coil, measured at the top coil (Tc).
(Color online) Same as Fig. 4 on the left hand side, with dimensionless frequency and EMF. On the right hand side, numerical simulations of harmonic responses.
(Color online) A synthetic response to the pulse in the coil is calculated from the harmonic response and plotted for comparison next to the actual response to the pulse (B = 13 T).
(Color online) Electromotive force in the four coils Lc, Mc, Uc, and Tc, following a pulse, at B = 13 T, as a function of dimensionless time.
(Color online) Mesh used (coarse version for easy visualization) to calculate Alfvén waves with FreeFem ++ : meridional plane of an axisymmetrical geometry with symmetry axis on the left.
(Color online) The numerically calculated pulse response is compared to the experimental measurements (B = 13 T).
(Color online) Reflexion of an Alfvén wave on the top end of the cylinder with SFEMaNS: meridional plane of an axisymmetrical geometry with symmetry axis on the left.
(Color online) Magnetic and kinetic energies during propagation and reflection of an Alfvén wave. Note that here the origin for time is taken at the peak of the electric current pulse.
(Color online) Iso-contours of magnetic streamfunction for Lundquist numbers 100, 800, and 6400 at Alfvén time 0.5, on the left hand side. Dimensionless EMF for Lundquist numbers from 100 to 6400 measured at the top coil.
Article metrics loading...
Full text loading...