Laboratory model of electro-vortex flow with thermal gradients, for liquid metal batteries*

To facilitate the adoption of renewable sources of energy, grid-scale storage options are needed. One promising solution to this problem is the liquid metal battery (LMB). The fluid dynamics of LMBs can be paramount to their operation and efficiency. It is thus important to develop a broad understanding of how various flow drivers interact with one another in a reduced model, whose results can be scaled to full-size LMBs. We designed and constructed a novel laboratory device to explore the interactions between two prominent drivers — thermal gradients and electro-vortex flow (EVF) — over broad ranges of governing parameters. We apply these forces to a layer of liquid gallium to simulate a single layer of an LMB, collecting temperature data with thermocouples and velocity data with Ultrasonic Doppler Velocimetry (UDV) probes. Using this experimental setup, we demonstrate scaling relationships with the Reynolds number, for both thermal convection and EVF individually, that agree well with theory and previous experiments and simulations. Our setup will establish a launching point for further understanding of flow characteristics in LMBs, and introduce novel methods for studying these flows.