Aerodynamics of jump in downhill ski racing

The paper presents a study about the aerodynamics of jump in downhill skiing. The activity consisted of wind tunnel investigation in a large wind tunnel where several different positions (corresponding to the different phases of take off, flight and landing) have been tested thanks to an apposite rig and to two athletes (in the following referred as “Skier A” and “Skier B”). Drag, lift and pitching moment have been measured by means of strain gauge balances. In order to acquire the actual skier position during the test a motion analysis system, equipped with six video-cameras, was used. Anthropometric measures and dedicated algorithms were used to estimate and filter 3D coordinates of internal joint centers and joint angles. Finally, a simple dynamic model of the skier during the jump has been implemented in a prediction code that compute, on the base of bump shape, the jump trajectory and duration.