Models for Droplet Motion on Hydrophilic and Hydrophobic Surfaces

Water droplet flows on surfaces have been numerically investigated using a new hybrid dynamic contact angle approach and four others, which include Kistler, Yokoi, Cox and OpenFOAM models, and the computations are compared with the experimental data. Two surface types, hydrophobic and hydrophilic are used to show the influence of surface wettability. Results put in evidence that the motion of droplets is very dependent on the formulation of the dynamic contact angle in relation to the wettability of surfaces. On the hydrophobic surface, the Yokoi and Cox models deviate significantly from the experimental data, whereas hybrid (proposed model) can be described as the most successful model. On the hydrophilic surface, the hybrid model imitates droplet dynamics very successfully, but the Yokoi model shows the best agreement with the experiments. It is clearly seen that the hybrid model can be accepted as one of the most successful models in multi-phase flow simulations with three-phase points.