Vertical Air Model for a Snowboard Course Design Based on the Dynamic Theory

摘要

The shape of the half-pipe has a certain influence on vertical air ("Vertical air" is the maximum vertical distance above the edge of the halfpipe). How to determine the shape of a snowboard course to maximize the production of "vertical air" by a skilled snowboarder is a problem for designer. In this paper, we firstly build a metric and quantify the design elements: slope angle, transition and flat-bottom. Based on the kinetic theory, we analyze the snowboarder's load conditions when he is sliding in the half-pipe, and develop a kinetic model about the geometrical characteristic and vertical air of the half-pipe. Thus, we obtain the shape distributed function with the objective of maximizing the vertical air. According to the distributed function, we figure out the design elements of the half-pipe with maximum vertical air: slope angle=18degree, flat-bottom-0.4m, transition length=l 0.25m and wall angle=60degree. After modeling, we analyze the sensitivity of the model and find that the vertical air of the half-pipe is determined mainly by the slope angel and transition, and the flat-bottom also has an influence on it, but not obvious.