| 초록 |
Evaporation is a common phenomenon that occurs in everyday life. However, most former studies were done on the evaporation of a small sessile drop, and systematic approach on the evaporation rate of a heavy drop is insufficient. Drop shape is determined by relative effect of gravitational force and surface tension. When gravitational force dominates surface tension, a drop on a substrate looks like a pancake shape, which is called puddle. On the other hand, when surface tension dominates gravitational force, a drop on a substrate looks like a spherical cap shape. Two relative forces are expressed by dimensionless number Bo, and usually, Bo of 30 is the starting point of a puddle changes to a small drop. In this study, drop profile of viscous liquid changing from a puddle to a small drop by evaporation is calculated by Mathematica and compared with real drop profile change during evaporation which was observed through CCD laser equipment and scale. From the results, it is expected to predict and help understand evaporation occurring at general surfaces in industry. |
