A fully transient approach on evaporation of multi-component droplets

This paper deals with multi-component droplet evaporation. For this purpose, species, momentum, and energy equations for the gas phase are solved numerically together with species and energy equations of the liquid phase. A fully transient (FT) approach with variable properties in terms of time and space is employed. The results are compared with available experimental data in the literature for binary- and multi-component droplets at various temperatures and satisfactory agreements are seen. In order to study the effect of volatility on the droplet evaporation, heptane, decane, and hexadecane are examined and multi-staged feature of evaporation is captured. Also, the range of droplet internal bubbling is estimated by investigating internal temperature and mass fraction variations. The results indicate that diffusion enthalpy term in the liquid phase plays a significant role in the deviation of multi-component droplet evaporation trend from the single component. Furthermore, the quasi-steady (QS) assumption in the gas phase of droplet evaporation is evaluated. The comparison between FT and QS approaches shows that the amount of heavier component in the droplet composition and increasing volatility difference of components increase the deviation of two approaches. (C) 2017 Elsevier Ltd. All rights reserved.