Penalty and Eulerian–Lagrangian VOF methods for impact and solidification of metal droplets plasma spray process

• Volume of fluid sub mesh method is applied for the first time to liquid–solid phase change.
• Viscous penalty method is used to handle solid behavior in the solidified part of liquid phase.
• Wetting effects are modelled by a penalty smooth VOF approach.
• The impact and solidification of a tin droplet is simulated and validated against experiments.
• The effect of thermal contact resistance is investigated on the droplet impact problem.

The direct numerical simulation of the impact and solidification of a tin droplet on a solid substrate is investigated by means of a volume of fluid sub-mesh method Vincent et al. (2010), which is extended for the first time to the solving of the energy equation with phase change. In addition, viscous penalty methods are proposed to treat the solidifying part of the droplet as it spreads onto the target substrate. The presence of a thermal contact resistance is also tackled within the proposed model. The numerical modeling is validated against various typical configurations of phase change with interface that provide analytical solutions. Among them, we can cite the contact of two materials with a thermal contact resistance or the Stefan problem for the propagation of a solidification front. The last part of the article is devoted to the numerical simulation of the impact of a tin droplet on a flat substrate. The simulations are compared to experiments of Aziz and Chandra (2000) and a study on the value of the thermal contact resistance is proposed.