A novel smoothed particle hydrodynamics formulation for thermo-capillary phase change problems with focus on metal additive manufacturing melt pool modeling

Laser-based metal processing including welding and three dimensional printing, involves localized melting of solid or granular raw material, surface tension-driven melt flow significant evaporation due to the applied very high energy densities. The present work proposes a weakly compressible smoothed particle hydrodynamics formulation for thermo-capillary phase change problems involving solid, liquid gaseous phases with special focus on selective laser melting, an emerging additive manufacturing technique. Evaporation-induced recoil pressure, temperature-dependent tension wetting forces are considered as mechanical interface fluxes, while Gaussian beam heat source evaporation-induced losses thermal fluxes. A novel stabilization scheme is proposed, which shown allow stable smooth liquid-gas by effectively damping spurious flows typically occurring in continuum force approaches. Moreover, discretization strategies tangential projection temperature gradient, required discrete Marangoni forces, critically reviewed. proposed deemed especially suitable modeling pool dynamics because full range relevant explicit resolution atmospheric gas enables consistent description pore formation inclusion. accuracy robustness individual model method building blocks verified means several selected examples context process.