Computer simulations of evaporation of sessile liquid droplets on solid substrates

Present work is focused on the numerical study of evaporation of sessile liquid droplets on top of smooth solid substrates. The process of evaporation of a sessile liquid droplet has lots of different applications both in industry and research area. This process has been under study for many years, and still it is an actual problem, solution of which can give answers on some fundamental and practical questions. Instantaneous distribution of mass and heat fluxes inside and outside of an evaporating sessile droplet is studied in this research using computer simulations. The deduced dependences of instantaneous fluxes are applied for self-consistent calculations of time evolution of evaporating sessile droplets. The proposed theory of evaporating sessile droplets of liquid has been validated against available experimental data, and has shown a good agreement. Evaporation of surfactant solution droplets is studied experimentally. The theory, proposed for two stages of evaporation, fits experimental data well. An additional evaporation stage, specific for surfactant solutions, is observed and described. Mathematical modelling of this stage requires further research on surfactant adsorption and its influence on the value of receding contact angle. Numerical study of the evaporation of microdroplets is conducted in order to evaluate the significance of different evaporation mechanisms (diffusive and kinetic models of evaporation) and different physical phenomena (Kelvin s equation, latent heat of vaporization, thermal Marangoni convection, Stefan flow).