Numerical analysis for a two dimensional case of two–phase fluid flow has been performed to investigate droplet impact, deformation for a droplet train. The purpose of this investigation is to study the phenomenon of liquid droplet impact on a liquid film created by a flattened droplet and the consequent deformation of the film while merging and advancing of the moving front of the film, during the manufacturing processes with jetting technology such as a direct printing process and inkjet printing. This investigation focuses on the analysis of interface tracking and the change of shape for an impacted droplet of a dispensed material. Investigations have been made on the performance of an adaptive quadtree spatial discretization with geometrical Volume–Of–Fluid (VOF) interface representation, continuum–surface–force surface tension formulation and height-function curvature estimation for interface tracking during droplet impact deformation and coalescence of droplet and liquid film produced by flattened droplets to form a printed line. Gerris flow solver, an open source finite volume code, has been used for the numerical analysis which uses a quadtree based adaptive mesh refinement for 2D. The results have been compared with an experimental result from the literature. The investigation has been performed for Reynolds number, Re of 21.1; Weber number, We of 93.8, and contact angle, θ of 30°. For the experimental result considered, the frequency of jetting is 12 kHz.
Liquid Film Flow Generated by High-speed Droplet Impact in Low-pressure Environment
