Ultrasound Doppler velocimetry for liquid metal batteries

The Tayler instability (TI) due to current flow through a liquid GaInSn column is under consideration here. It is a consequence of electric current surpassing a critical value in the order of a few kA and manifests itself as a stack of vortices. Two ultrasound transducers encased in a copper electrode on top of the column were used to measure the vertical component of the liquid metal flow caused by the TI, which is of the order of several mm/s. UDV measurements were only possible after noise suppression mechanisms were added to the experimental setup. The results of the UDV retrievals will be discussed here.