Stirring with Rotating Magnetic Fields: Numerical and Experimental Results

This work is concerned with the convection in a finite cylinder driven by a rotating magnetic field. Both direct numerical simulation (DNS) and experiments have been carried out to study the characteristics of this kind of confined flows. A decoupling of the mathematical model into the Navier-Stokes equations and an a priori known Lorentz force was achieved in the usual manner by employing the rigid-body and the low-frequency approximations. Adams-Bashforth time integration has been combined with a second-order finite element method for the discretisation. Utilising the upcoming technique of Ultrasonic Doppler Velocimetry (UDV) allowed for a mapping of the meridional velocity components throughout an entire section of the container. In a more quantitative fashion potential difference measurements (PDM) were performed to support and validate the numerical results.