Half pipe-snow board 毕业论文翻译定稿-.docVIP

Half pipe-snow board Summary This essay mainly discusses two problems. One is to determine the shape of a snowboard course to maximize the production of “vertical air”; the other is to modify the shape of the course to allow for the performance of certain snowboarding movements and decide what tradeoffs may be required to develop a “practical”course. First, the following assumptions are made: no wind in the course; the snowboarder being a skilled one; the transitional zone being arc-shaped, and the entry starting from the leading edge of the course at a fixed initial velocity. Second, to deal with the first problem, the course is taken as an arc. The optimization mathematical model of the course is build with vertical air as the target function. Given the multiple variables involved, certain variables are artificially fixed to study the influence of some variable has on the vertical air. The major conclusion is: width of the flat bottom is in inverse proportion to the vertical air. In theory, to get the largest vertical air, the width should be minimized. When the width reduced to zero, the maximum vertical air is 7.152080m. When conducting sensitivity analysis, we find the minor change in width of the flat bottom has little impact on the final results. However, in reality, the flat bottom is necessary as it provides the snowboarder a chance to adjust his movement before entering the arc transitional zone. The second problem focuses on the maximization of the twist in the air. The initial velocity is disintegrated into two directions to ensure the remaining potential energy conversed from the off-slot kinetic energy must reach its maximum amount. An optimization model with maximum twist and vertical air as the target function is similarly set. The conclusion is that when a skilled snowboarder enters the course at an initial velocity of 11.96m/s, the ideal maximum vertical air he achieves is 5.367006m, and under this condition, the maximum twist in the air is als