How do drops evaporate?

TL;DR

This paper develops a unified mathematical model for the evaporation of pure liquid drops on conductive substrates, comparing two different evaporative flux models and validating with experiments to determine their applicability.

Contribution

It introduces a single governing equation that incorporates both liquid-phase and vapor-phase evaporation models, aiding in selecting the appropriate model experimentally.

Findings

Unified governing equation for drop evaporation.

Experimental parameters estimate for model validation.

Guidelines for choosing evaporation models based on conditions.

Abstract

We consider evaporation of pure liquid drops on a thermally conductive substrate. Two evaporative models are considered: one that concentrates on the liquid phase in determining evaporative flux, and the other one that centers on the gas/vapor phase. A single governing equation for the evolution of drop thickness, including both models, is developed. Experiments are used to estimate relevant parameters. We show how the derived governing equation can be used to predict which evaporation model is appropriate under considered experimental conditions.