Magnetic induction and diffusion mechanisms in a liquid sodium spherical Couette experiment.

摘要: We present a reconstruction of the mean axisymmetric azimuthal and meridional flows in Derviche Tourneur Sodium installation Grenoble liquid sodium experiment. The experimental device sets spherical Couette flow enclosed between two concentric shells where inner sphere holds strong dipolar magnet, which acts as magnetic propeller when rotated. Measurements velocity, induced field, electric potentials have been acquired inside outside fluid for an rotation rate 9 Hz $(\text{Rm}\ensuremath{\simeq}28)$. Using induction equation to relate all measured quantities flow, we develop nonlinear least-squares inversion procedure reconstruct fully coherent solution velocity field. also include our response layer nonaxisymmetric time-dependent field that results from deviations imposed axial dipole. obtain shows superrotation region close Lorentz force dominates, contrasts with outer geostrophic governed by Coriolis force, but torque remains driver. circulation is strongly hindered presence both forces. Nevertheless, it contributes significant part energy. Our approach scene evaluating contribution fluctuations key question dynamo mechanisms.