Metallic droplet impact simulations on plasma-facing components

Multiphase Navier–Stokes simulations of liquid metal droplets colliding with solid plasma-facing components are carried out in conditions representative of magnetic confinement fusion devices. The flow dynamics of the spreading liquid are examined to assess the relative importance of various physical processes in the impact energy budget. Contributions from the initial droplet surface energy and the solidification-induced momentum sink are shown to be of great importance in determining the final geometry of the frozen spatter. Semi-empirical scaling laws available in the literature are adapted to provide robust predictions of the flattening ratio that can be extrapolated to general fusion-relevant impact scenarios.