Droplet evaporation near a planar reservoir

For a spherical droplet at fixed center height $h>R$ above a flat equilibrium reservoir, the diffusion-capacitance analogy and sphere-plane capacitance giveAt large separation, $c(R/h)=1+R/(2h)+O((R/h{)}^2)$, soThe nearby reservoir increases the total flux and shortens the lifetime. The spherical-shape assumption controls the geometry; the local current density is not uniform over the surface.