A computational fluid dynamics model using the volume of fluid method for describing the dynamics of spreading of Newtonian fluids

A numerical study is performed to describe the dynamics of drop spreading of glycerol-water mixtures with and without surfactant on hydrophilic glass surfaces. A computational fluid dynamics model (CFD), based on the volume of fluid technique (VOF), with piecewise linear interface calculations method (PLIC) for interface reconstruction, is applied to simulate the time evolution of spreading drops on solid surfaces (drop base radius and contact angle). Surface tension and wall adhesion phenomenon are included in the computational model. Numerical simulations with two-dimensional domains are sufficient to reproduce the key qualitative features observed in the experiments. The CFD simulations are quantitatively compared with previously published experimental results. The influence of different factors, such as viscosity, drop volume and non-ionic alkyl (8-16) glucoside (Plantacare 2000) surfactant concentration on the temporal evolution of the drop base radius is systematically investigated. More than 25 simulations have been performed in order to obtain detailed quantitative comparison and clear trends. We have shown, using several independent experiments, that the calculated results compare very well with experimental data for a large range of viscosity (0.02-1.15 Pa s), drop volume (8-60 mu L) and in the presence of surfactant. The accuracy of the model demonstrates that the influence of the physical-chemical properties of the liquid such as viscosity, volume and surface tension can be successfully simulated. (C) 2011 Elsevier B.V. All rights reserved.