Experimental study of the flow driven by combined AC magnetic fields using a novel ultrasound array system

Ultrasound velocity measurements were performed in a liquid metal flow (GaInSn) inside a cubic vessel. The flow was driven by the combined action of a rotating (RMF) and a travelling magnetic field (TMF) leading to an inherent three-dimensional electromagnetic force distribution in the fluid. As a result flow structures develop which are essentially determined by the frequency difference and the strength relation of both fields. The driving force is stationary for identical frequencies whereas it undergoes a slow temporal modulation in case of slightly varying frequencies. Beside the magnetic field parameter the alignment of the TMF’s to the fluid volume’s axis plays a crucial role. A novel ultrasound array system was used in the present study to measure two velocity components in two perpendicular planes (2d-2c) simultaneously. This contribution reports on the influence of axial alignment on the flow, and on the flow dynamics resulting from slightly different field frequencies of the RMF and the TMF.