Investigation of effects of surface texture on ice formation

• Main Author: Wang, Qiuping
• Other Authors: Chan Weng Kong
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2020
• Subjects: Engineering::Aeronautical engineering::Aircraft; Engineering::Aeronautical engineering::Materials of construction; Engineering::Mechanical engineering::Fluid mechanics
• Online Access: https://hdl.handle.net/10356/141028
• Institution: Nanyang Technological University

Superhydrophobic surfaces are one of the focuses in developing new anti-icing techniques in the aerospace industry. Its excellent water repellent performance makes it an appealing application in anti-icing methods. Hence, exploring the relationship between hydrophobicity and icephobic properties could be beneficial in developing anti-icing techniques for aerospace industry in the future. In this project, 1100 aluminum alloy is used in this experiment because it is an ideal material used in aircraft’s fan blades, engine cowling, fuel tanks and repairing material for wingtips. They are chemically etched to obtain different contact angles. Based on the previous research, the hydrophobicity of the test plates is affected by the duration of etching and concentration of etchant. The result shows that there is a critical etching duration and etchant concentration beyond which the hydrophobicity would decrease. From the experimental result, a test plate etched with 4M HCL for 5 minutes would obtain an optimal contact angle of 160.57°. Plasma cleaning is employed to achieve a hydrophilic surface, the results show that 10 minutes of plasma cleaning is required to achieve a contact angle of 24.82°. In order to determine the icephobic properties of the test plates at different contact angles, test rig has been set up to allow the icing experiment to be conducted under dynamic airflow conditions. A capacitive sensing method was also employed to analyze the ice formation process. The results show that surfaces with contact angle more than 140° demonstrate a delay in ice formation. A contact angle of 160.57° has shown a longer delay in ice formation. However, other test plates with contact angle less than 140° shows a similar rate of ice formation. It is also observed that the icephobic properties such as delaying ice formation are not directly related to the surface roughness.