Simulations of beryllium castellation gap bridging during vertical displacement events

Multiphase Navier–Stokes simulations of castellated beryllium plates exposed to JET-like disruption plasma loads are performed to investigate melt transport in the vicinity of gaps and the formation of re-solidified bridges between adjacent castellation blocks. It is found that two-dimensional computations are able to predict whether bridging occurs and that they agree with experimental data in terms of characteristic melt infiltration depths and global material transport along the surface. However, three-dimensional set-ups appear to be necessary when estimates of the damaged component’s surface morphology are sought in cases where bridging does not occur. Comparisons with simplified shallow-water models confirm that such models are applicable to scenarios in which bridges have already been formed, although they tend to overestimate the net melt displacement.