Internal flow in evaporating droplet on heated solid surface

This work numerically studies the evaporation process of a liquid droplet on a heated solid surface using a comprehensive model. The internal flow within the evaporating liquid droplet is elucidated, while considering the effects of buoyancy force, thermocapillary force, and viscous resistance. The evaporation process is modeled by simultaneously solving the Navier-Stokes equations and energy equation for the liquid domain and the heat conduction equation for the solid domain, while assuming the liquid-vapor interface is a free surface. Three dimensionless parameters are utilized to describe the contribution of individual driving forces to internal flow. Evolutions of the thermal and internal flows during evaporation are discussed. The volume evolution and experimental data are in good agreement. (C) 2011 Elsevier Ltd. All rights reserved.