Effects of miniature filament on flow characteristics

• Main Author: Tan, Sandy Jit Yong
• Other Authors: Chan Weng Kong
• Format: Final Year Project
• Language: English
• Published: 2019
• Subjects: DRNTU::Engineering::Aeronautical engineering
• Online Access: http://hdl.handle.net/10356/77413
• Institution: Nanyang Technological University

Many sports rely on equipment to enhance their performance to achieve competitive advantage over their competitors. In particular, sports compressions and apparels can have a huge influence on the outcome of the competition through drag reduction. Generally, the drag experienced by an athlete in motion is greatly affected by the surface morphology of the sports fabric which in turn affects its aerodynamic properties. Since fabric orientation, composition as well as stretch level of the fabric, play important roles in determining the surface morphology of the fabric, appropriate fabric orientation, composition and stretch level can provide aerodynamic advantages. In this study, 5 different fabrics with differing compositions were tested using cylindrical methodology at different stretched conditions and orientations, over a range of Reynolds numbers. The results from the wind tunnel testing were analysed by comparing them with Scanning Electron Microscope (SEM) images taken at different stretched conditions. From the results of the experiment, it was established that the surface morphologies of the fabrics were different at different stretched conditions, causing observable effects on aerodynamic drag. Results also indicate that drag coefficients at high and low speeds can be reduced by stretching the fabrics from their normal fit conditions, and CDmin is lower for stretched as compared to unstretched condition. It can also be suggested that fabrics with filaments orientated at 90⁰ tend to undergo earlier flow transition as compared to them at 0⁰. In addition, recommendations on the types and orientations of the fabric used at different speed ranges were provided based on the samples used in this study.