TY - JOUR
TI - Study of transient condensation occurring during the starting of the evaporation of a droplet deposited on a heated substrate
AU - Khilifi Dorra
AU - Foudhil Walid
AU - Fahem Kamel
AU - Harmand Souad
AU - Ben Jabrallah Sadok
JN - Thermal Science
PY - 2020
VL - 24
IS - 6
SP - 4075
EP - 4087
PT - Article
AB - The evaporation of a drop deposited on a heated substrate is a complex process, which combines several phenomena such as the Marangoni effect, mass and thermal transfers, etc. We developed, in this paper, a mathematical model and a numerical simulation code used to carry out an in-depth study about the evaporation of a drop deposited on a heated substrate surrounded by air. This numerical study was supported by experimental work. The numerical findings obtained showed the existence of a condensation phenomenon for certain configurations. At the beginning of the experiment, the evaporation started at the triple point. However, a local region of the interface remained relatively cold. In this region, the concentration gradient (Cv, Csat) directed from the liquid-gas interface to the air resulted in condensation of water steam. Although this phenomenon is temporary and visible only at the start of evaporation process, its study makes it possible to better understand and optimize the evaporation kinetics.