Localized Thermal Analysis for Sportswear via Wind Tunnel Testing

Thermal comfort of sportswear is critical for optimizing athletic performance and improving safety. However, current research on the convective heat transfer coefficient (h) between fabrics and the air flow remains limited, especially in terms of its local analysis. In this study, a thermal cylinder which simulates human limb was developed to evaluate the fabrics' thermal insulation (It) and h (both local and global values) in the wind tunnel. The wind speed ranged from 2 to 8 m/s, and the stretch ratio (SR) from 1.1 to 2.0. The results show that for both fabrics, the local h reaches a minimum around θ = 80°-90°, while the local It peaks near θ = 120°. The effects of SR and wind speed on It and h are also reported. This work offers a practical method for quantifying the heat transfer characteristics of stretched fabrics, providing theoretical guidance for sportswear design and thermal regulation strategies in wind environment.