Frictionless flow in channels

• Main Author: Tan, John Ding Hao
• Other Authors: Chan Weng Kong
• Format: Final Year Project
• Language: English
• Published: 2015
• Subjects: DRNTU::Engineering::Mechanical engineering::Fluid mechanics
• Online Access: http://hdl.handle.net/10356/64564
• Institution: Nanyang Technological University

The effect of drag reductions in pipelines play a major role in piping industry for cost saving. Methods available in drag reduction are, surface coating, addictive adding, pipe material substitution. This project aims to achieve drag reduction in channel using the surface coating method. Thus, this project makes use of a polydimethylsiloxane (PDMS) coating which is used on microchips due to its hydrophobicity. A total of 9 specimens of Graphite and Teflon were coated with PDMS and with various carbon content mixtures of sizes 44 micron and 10 micron with PDMS. Each specimen is attached on an acrylic channel running with water to test out the effectiveness of drag reduction. The pressure difference readings are collected and tabulated. A low pressure difference across the channel indicates a lower friction. From the experiment, surface coating of mixture of PDMS and Carbon at ratio of 44 micron to 10 micron powder of 1: 2 was able to achieve drag reduction. At this particular coat setting the contact angle measured was the highest for both Teflon and Graphite specimens. These results shown that as the contact angle measured increases the drag reduction capability improves. This is largely due to the surface energy which leads to the amount of energy required to push the water across the surface.