Numerical analysis of ski suits surface roughness effects on aerodynamics during the in-run phase of ski jumping

The study employs the shearstress transport (SST) turbulence model within a computational fluid dynamics (CFD) framework to investigate the influence of skijumping suit surface roughness on aerodynamic performance during the in-run phase. A three-dimensional multi-body model of the athlete-ski system is constructed to access variations in aerodynamic drag, moments, and flowfield characteristics under different surface roughness conditions. The results show that surface roughness has a significant effect on pressure drag, influencing both the total aerodynamic drag and the generation of pitching and rolling moments. While a surface roughness of 17.036[Formula: see text] yields the lowest total drag, it doesn't correspond to minimal moments, indicating a trade-off between drag reduction and aerodynamic stability. Flow field analysis reveals that moderate surface roughness promotes earlier boundary-layer transition and delays flow separation, thereby enhancing aerodynamic efficiency. These findings highlight the importance of balancing drag minimization and stability control in suit design. The study provides theoretical basis for material selection and performance-driven customization of ski-jumping suits, with implications for the development of optimized apparel for elite athletes.