Evaporation-limited hemispherical imbibition
= Evaporation-limited hemispherical imbibition
{title2=$R_*=(R_s+\sqrt{R_s^2+4k\Delta P R_s/(\mu F_e)})/2$}
When a hemispherical wetted front loses liquid at fixed volumetric flux per unit area $F_e$, equilibrium balances inlet flow with $2\pi R^2F_e$. The displayed radius exceeds $R_s$ and is stable because inlet flow decreases while evaporating area increases with radius. <Porosity> affects the adjustment time but cancels from the equilibrium radius.