Evaporation and fluid dynamics of a sessile drop of capillary size.

Journal Article · Thu Jan 01 04:00:00 EST 2009 · Phys. Rev. E

DOI:https://doi.org/10.1103/PhysRevE.79.046301· OSTI ID:962564

Barash, L Yu; Bigioni, T P; Vinokur, V M; Shchur, L N

Theoretical description and numerical simulation of an evaporating sessile drop are developed. We jointly take into account the hydrodynamics of an evaporating sessile drop, effects of the thermal conduction in the drop, and the diffusion of vapor in air. A shape of the rotationally symmetric drop is determined within the quasistationary approximation. Nonstationary effects in the diffusion of the vapor are also taken into account. Simulation results agree well with the data of evaporation rate measurements for the toluene drop. Marangoni forces associated with the temperature dependence of the surface tension generate fluid convection in the sessile drop. Our results demonstrate several dynamical stages of the convection characterized by different number of vortices in the drop. During the early stage the array of vortices arises near a surface of the drop and induces a nonmonotonic spatial distribution of the temperature over the drop surface. The initial number of near-surface vortices in the drop is controlled by the Marangoni cell size which is similar to that given by Pearson for flat fluid layers. This number quickly decreases with time resulting in three bulk vortices in the intermediate stage. The vortices finally transform into the single convection vortex in the drop existing during about 1/2 of the evaporation time.

• Research Organization: Argonne National Laboratory (ANL)
• Sponsoring Organization: SC
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 962564
• Report Number(s): ANL/MSD/JA-64740
• Journal Information: Phys. Rev. E, Journal Name: Phys. Rev. E Journal Issue: 2009 Vol. 79; ISSN PLEEE8; ISSN 1063-651X
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
COMPUTERIZED SIMULATION
DIFFUSION
DROPLETS
EVAPORATION
HYDRODYNAMICS
SURFACE TENSION
THERMAL CONDUCTION
TOLUENE
VAPORS