Aerodynamic Performance of Manufactured Surface-Textured Speed Skating Fabrics

In high-speed sportswear, fabric manufacturing decisions, including surface texturing and face/back orientation, can influence boundary-layer behavior and aerodynamic drag. Although previous aerodynamic textile studies have mainly examined surface roughness, fabric structure, or garment design, the manufacturing orientation of surface-textured fabrics has received less attention. This study conducted a manufacturing-oriented wind-tunnel evaluation of speed skating suit fabrics with controlled differences in dimple orientation and exposed surface condition.

Four configurations were compared using the same base fabric: dimpled surface inward (DI), dimpled surface outward (DO), normal standard surface inward (NI), and normal standard surface outward (NO). Fabric specimens measuring 100 mm × 250 mm were attached to both sides of a symmetric wing-shaped model, resulting in a total reference area of 0.050 m². Drag force was measured at flow velocities of 10–20 m/s, corresponding to Reynolds numbers of approximately 1.72 × 10⁵–3.44 × 10⁵, and the drag coefficient was calculated.

Across the tested velocity range, NI exhibited the lowest drag coefficient, whereas DO consistently showed the highest. DI produced intermediate values but remained lower than DO, indicating that placing the dimpled structure on the inner side while maintaining a smoother external surface was more aerodynamically favorable under the present conditions. NO showed a non-monotonic increase in drag coefficient above approximately Re = 3.09 × 10⁵. These findings suggest that aerodynamic performance is affected not only by surface microstructures but also by their manufacturing orientation relative to the external flow. However, because a simplified wing-shaped model and limited repetitions were used, the results should be interpreted as relative trends. Further studies incorporating fabric stretch, seam construction, and body geometry are required for garment-level optimization.