| Affiliation: | 1. East China University of Science and Technology, School of Mechanical and Power Engineering, Meilong Road, 200237 Shanghai, China;2. East China University of Science and Technology, State Key Laboratory of Chemical Engineering, Meilong Road, 200237 Shanghai, China East China University of Science and Technology, State Environmental Protection Key Lab of Environmental Risk Assessment and Control on Chemical Process, Meilong Road, 200237 Shanghai, China;3. East China University of Science and Technology, State Key Laboratory of Chemical Engineering, Meilong Road, 200237 Shanghai, China |
| Abstract: | The evolution of droplet shapes on a hydrophilic copper mesh was studied by using high-speed microscopic imaging technology. When a water droplet wets a hydrophilic mesh, the liquid-vapor interface initially adopts a convex shape, named as the “first darkness”. Then, as the water evaporates, the liquid-vapor interface flattens, and then it gradually adopts a concave shape; meanwhile, a “second darkness” forms. Taking the shapes of droplets sunken in holes into consideration, the quantitative liquid-vapor interface area was acquired. The evaporation coefficient becomes lower and more reasonable when considering the area increase due to the pentahedron sunken liquid in the holes. A speculation was employed to understand the observed evaporation behavior and the overprediction of the evaporation coefficient. |
