Numerical simulation of the MHD flow produced by a rotating magnetic field in a cylindrical cavity of finite length

The laminar swirling flow in a simple flat-bottomed cylindrical cavity driven by a rotating magnetic field was examined numerically. It was shown that compared to the case of conducting end walls, the induced electric current closing within the liquid volume near its nonconducting end walls significantly modified both the distribution and the total magnitude of the electromagnetic torque affecting the liquid column. It was demonstrated that this, in turn, changed the secondary recirculating flow structure. The instability was found to be caused by a small-scale toroidal-type secondary vortex arising around the stagnation point between adjacent secondary vortices in the boundary layer on the side wall. A comparison of the obtained numerical results with the available experimental measurements of the corresponding flow regimes showed a reasonable agreement.