Unsteady aerodynamics simulation for the influence of difference in posture change on aerodynamics and flight distance in ski jump take-off motion

Abstract

The ski jumper rapidly changes the body posture from crouching to flight posture during take off. In this study, the relationship between flight distance and take-off motion, in terms of trunk angle of attack and lift-drag ratio, was investigated through aerodynamics simulations that reproduce the take-off motion dynamically. The trunk angle of attack was extracted from two-dimensional image in the sagittal plane of the take-off motion. From the results of the numerical simulation it was found that athletes with higher lift-drag ratio at the initial take-off posture had longer flight distance and the frontal pressure on these athletes was relatively lower.