Droplet impingement on a heated surface

• Main Author: Chia, Patrick Chee Leong
• Other Authors: Fei Duan
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2021
• Subjects: Engineering::Mechanical engineering
• Online Access: https://hdl.handle.net/10356/150176
• Institution: Nanyang Technological University

Droplet impingement behaviours affects the surface performance for multiple applications such as heat transfer, boiling and anti-icing and condensation. This study looks into the dynamics of droplet impingement on a hybrid surface of hydrophilic and super-hydrophobic nature. The test specimen will be specially fabricated to have half the behaviour of hydrophilic and half of hydrophobic. The impinging droplet will be dropped in a controlled environment onto the interface separating the hydrophilic and hydrophobic side. The variables for this study will be the temperature range of 50-340C and droplet velocity as a consequence of variation in drop height (10-70mm). Surface impingement of water droplets depend on the nature of fluid and surface interaction. This study will look at the various phenomena that occurs as result of the surface interaction with the impinging droplet. To study the impingement behaviour on a heated surface we employ the help of a high speed camera to capture the side profile of the impingement process. Also, an Infrared camera is used to capture the top view of this process. Results discussed in this study will be primarily based on the results from the high-speed camera with the Infrared imaging results to be used as a supplement for further analysis. In our analysis it was found that weber number has a large impact on the spreading diameter of the impinging droplet. Furthermore, the hydrophilic properties had a heavy influence on the receeding regime and the boiling regime of the impinging droplet. The results obtained from this study is backed with theoretical data explained in the following sections. While the study of impingement behaviour is growing field of interest. Further studies can be done to look at impingement droplet of varying mediums on a hybrid surface.