Numerical Study on Evolution of Sessile Water Droplets During Evaporation Available to Purchase

The evaporation of sessile water droplets has been investigated numerically in this paper. A numerical model based on the quasi-stationary assumptions is established for describing the evaporation dynamics. Droplets are assumed to be pinned and axisymmetric on a substrate during the evaporation, and the influence of Marangoni effect on the evaporation has been taken into account. In a self-consistent way, the vapor concentration field in the gas phase, the velocity field in the liquid phase, and the temperature field in both liquid and gas phases have been calculated using the finite element method (FEM). A novel iteration algorithm is proposed to study the time evolution of contact angle. From the numerical results, we derived a universal correlation of the contact angle with the dimensionless time. The correlation, which is validated against experimental data from open literature, is independent on the contact radius, substrate temperature and ambient humidity. Base on this correlation, a simple expression has been further developed to estimate the evaporation time, and the predictions are in good agreement with the experimental results from open literature. The work in this paper provides an extensive understanding of the evaporation of sessile droplets.