Droplet evaporation in one-component fluids: Dynamic van der Waals theory

TL;DR

This study models droplet evaporation in one-component fluids using dynamic van der Waals theory, revealing temperature distribution and evaporation behavior near the contact line on heated substrates.

Contribution

It applies dynamic van der Waals theory to analyze evaporation dynamics and temperature profiles in one-component fluid droplets on heated surfaces.

Findings

Temperature near the interface is close to equilibrium temperature away from the substrate.

Evaporation occurs mainly near the contact line in late stages.

Temperature sharply rises to wall temperature near the substrate.

Abstract

In a one-component fluid, we investigate evaporation of a small axysymmetric liquid droplet in the partial wetting condition on a heated wall at $T\sim 0.9 T_c$. In the dynamic van der Waals theory (Phys. Rev. E {\bf 75}, 036304 (2007)), we take into account the latent heat transport from liquid to gas upon evaporation. Along the gas-liquid interface, the temperature is nearly equal to the equilibrium coexisting temperature away from the substrate, but it rises sharply to the wall temperature close to the substrate. On an isothermal substrate, evaporation takes place mostly on a narrow interface region near the contact line in a late stage, which is a characteristic feature in one-component fluids.