競技用ウエア生地のマクロ粗さとミクロ粗さの組み合わせによる空力への影響

抄録

The purpose of this study is to clarify the relationship between the surface shape and aerodynamic characteristics of knitted fabrics used in sports garment fabrics. In particular, the study examined how the combination of macro roughness (e.g. grooves and dimples) and micro roughness (coarseness due to the weave) affects fluid phenomena. Using wind tunnel experiments and particle image velocimetry (PIV), the drag characteristics and flow in the wake region of five different types of knitted fabric were analyzed. As a result, drag crises were observed in three types of fabric: Dimple, Simple + Rib, and Groove. In particular, the drag area SD was minimized at U = 10 m/s for Dimple, U = 12 m/s for Simple + Rib, and U = 14 m/s for Groove. On the other hand, no significant changes were observed in the fabrics of Simple and Rib. In the PIV measurements, the wind speed U at which the minimum SD and the minimum width of the low-speed range were observed were the same for Dimple, but they were different for Simple + Rib and Groove. The results of this study are expected to contribute to the selection and design of fabrics that consider the interaction between macro and micro roughness in the development of sports garment fabrics.