The Significance of Fabric Permeability of a Ski Jumping Suit in Fluid Dynamics

Abstract

The sport of ski jumping is judged on the basis of flight form and flight distance, and it is important to increase the flight distance to win a ski jumping competition. The fabric used in ski jumping suits plays a crucial role in achieving favorable aerodynamic characteristics. In general, ski jumping suits with lower air permeability are considered to advantage the aerodynamic performance due to high lift generation. However, the aerodynamic characteristics were improved by the fabric with large air permeability in our previous study. The purpose of this study is to investigate the effect of air permeability on the aerodynamic characteristics of ski jumping suits by using the flow visualization technique. Wind tunnel experiments were carried out on the NACA airfoil clothed with ski jumping suit fabrics of different air permeability. It was confirmed that the aerodynamic characteristics of ski jumping suits are significantly influenced by air permeability because stall delay occurs and drag decreases with an increase in air permeability.