Conductivity influence on interfacial waves in liquid metal batteries and related two-layer systems

TL;DR

This paper investigates how conductivity distribution affects interfacial wave stability in liquid metal batteries, emphasizing magnetic damping and electric boundary conditions through numerical analysis.

Contribution

It provides new numerical insights into the role of conductivity and magnetic effects on interfacial wave instabilities in two-layer liquid metal systems.

Findings

Magnetic damping significantly influences wave stability under strong magnetic fields.

Electric boundary conditions critically affect the critical currents and growth rates of instabilities.

Conductivity distribution plays a key role in interfacial wave excitation and damping.

Abstract

Fluid flows in liquid metal batteries can be generated by a number of effects. We start with a short overview of different driving mechanisms and then address questions specific to the metal pad role instabilities in three-layer systems. We focus on the role of the conductivity distribution in the cell, noting at the same time that interfacial tension should be considered as well for smaller cells. Following this discussion, numerical results on the excitation of interfacial waves in two-layer liquid metal systems with miscibility gaps bearing an interface normal electric current are presented. Confirming recent results from the literature, we find that magnetic damping plays a decisive role for strong vertical magnetic fields. In addition, boundary conditions for the electric field strongly influence critical currents and growth rates.