Simulation of liquid-jet overflow in droplet deposition processes

Abstract

Porosity formation in spray deposition processes is investigated. The emphasis is on one possible mechanism of micro-pore formation during droplet spreading and solidification: liquid-jet overflow. To this end, the Navier–Stokes equations are solved numerically using finite differences and the free surface is tracked using the Volume of Fluid (VOF) method. A previously developed multi-directional solidification algorithm is adapted and implemented in the Navier–Stokes solver to perform numerical simulations of liquid-metal droplet impact, spreading, and solidification. The results obtained allow a detailed description of the liquid-jet overflow mechanism and of the resulting solidified disk morphology. The influence of the Weber and Reynolds numbers, the solidification constant, and the contact angle are investigated.