Dynamic behavior of current-through galinstan in liquid metal current limiter

This paper presents the experimental results on electromagnetic behavior of galinstan in liquid metal current limiter in case of rated and short circuit current respectively. For the former, the liquid keeps unstable in the channel like `boiling' when DC current of 1kA passes it and pinches to ignite the arc finally within the channel in several minutes, which is observed by a specially designed test setup. However, this related liquid column pinches regularly driven by the electromagnetic force in several milliseconds due to the short current and finally ignite the arc at both ends of the channel. In order to reveal their mechanisms, the contact characteristics between galinstan and channel wall are introduced and analyzed based on test measurement. Moreover, a numerical MHD model allowing for the liquid-wall contact characters is built to calculate its multiphysical distribution under different conditions. The results indicate that both behaviors have different detailed process but share the same intrinsic reason which results from the inhomogeneous magnetic pressure in current-through galinstan and its poor wettability of galinstan on the channel wall as well.