Evaporation Rate Profiles from a Liquid in a Cylindrical Hole

Profiles of local evaporation rate from a liquid surface formed in a cylindrical hole are numerically estimated using the finite element method. The droplet is so small that the evaporation can be considered as a steady-state process and the vapor concentration distribution above the droplet satisfies the diffusion equation. Generally, the local evaporation rate of a droplet is small at the center, but becomes stronger near the contact line on the flat substrate. In a cylindrical hole, the local evaporation rate near the contact line is prevented by the vertical sidewall especially for a high sidewall. The effect of bank height and the contact angle on the local evaporation rates and total evaporation rate are also discussed.