Optimizing coating processes can be difficult to model due to small scale of fluid motion and the influence of effects such as wall adhesion and surface tension. FLOW-3D provides a convenient way to analyze these processes without having to resort to costly laboratory experiments. FLOW-3D‘s models simulate surface tension gradients due to temperature variations, heat transfer, vaporization, condensation, solute transport and density-driven flows.

This 3D simulation shows a dip coating process with concomitant evaporation. A wet film is deposited by withdrawal of a small discrete substrate from a solution. The model additionally accounts for the evaporation of the solvent. This is relevant in the case of volatile solvent, for which evaporation overlaps with fluid mechanics during film deposition. The residue model provides the unique capability to calculate the profile of the coated dry film. The correct evaluation of the “edge effects” allows engineers to analyze the influence of process parameters or fluid properties on the final thin film geometry and homogeneity. Modeling courtesy of Roche Diagnostics.