THE EFFECTS OF UPPER LIMBS POSITION ON THE AERODYNAMICS IN SKI JUMPING FLIGHT

In ski jumping, the jumpers are moving with high speed (about 90-100 km/h) in flight phase, so that the fluid dynamics play an important role in their performance. We focused on the effects of the position of the upper limbs of a ski jumper on the fluid dynamics in flight position. The purpose of this study was to contribute to the improvement of flight style from a fluid dynamics point of view. We measured the aerodynamic form (drag and lift) of the flight position by a ski jumper model (H: 1.50 m) to investigate the effect of the hand and arm position on the aerodynamics in ski jumping. These experiments were done in the wind tunnel of Japan institute of Sports Sciences. The results showed that the aerodynamic forces could be changed by the body posture such as the angles of arm and hand.