소수성 텍스쳐 표면에 충돌하는 단일 액적 퍼짐 특성 연구

The present study aims to experimentally investigate the spreading characteristics of impinging droplets on hydrophobic textured aluminum (Al 6061) surfaces by using micro computer-based control (μ-CNC) milling machine. Textured surfaces were composed of micro-holes (diameter of 125 ㎛ and depth of 125 ㎛), and we examined the effect of the texture area fraction ranging from 0 to 0.568 on spreading characteristics during impact by measuring the apparent contact angles. A de-ionized(DI) water droplet of 4.3 ㎕ was impinged on textured surfaces at different Weber number ranging from 4.43 to 58.18, and a high-speed camera was used to capture sequential digital images for calculating maximum spreading diameter. It was found that the spreading rate decreased with increasing texture area fraction because of the increase in contact angle and viscous dissipation during the impact.