Slipstreaming is governed by interference drag (Hoerner, 1965). Yet, as in alpine skiing, speed is crucial and the first athlete that crosses the finish line wins, which in turn requires obeying aerodynamics principles. Baggy and fluttering clothing is another freestyle feature, actually prescribed by the ski cross rules (FIS, 2017, rule 4511.6 Suit Measurement). Although there is no judged component, these disciplines are still considered freestyle because of terrain features typical for freestyle. However, in 20 respectively, snowboard-cross and ski-cross became Olympic disciplines, where 4–6 athletes are racing against each other on the same track. Classical gravity-powered sports are bobsleigh (after the start phase), luge (after the start phase), skeleton, alpine skiing, ski jumping, and snowboarding. There is no single study on gravity-powered sports, probably because there is often only one athlete or team on the track rather than directly competing against each other. These sports disciplines, however, are muscle-powered, where slipstreaming reduces energetic demands. Slipstreaming or drafting is a commonly used strategy in sports, specifically in cycling (Barry et al., 2014, 2015), speed skating (Rundell, 1996), running (Pitcher, 2009), wheelchair racing, and other sports. The glide model presented in this research can be used in the future for testing of slope track design, provided that precise dimensions of terrain features are available. Making more ground up on the racing track is related to higher speed, less body mass (of both skiers), flatter slope angle, denser air, and higher racing posture (high tucked position of both skiers). The higher the trailing skier's inertial force and acceleration is compared to the leading one, the quicker the trailing skier can catch up. Different scenarios were tested as to their effect on slipstreaming, such as variation of speed, skiers' mass, slope angle, air density, and racing posture (high/low tucked position). A glide model consisting of leading and trailing skiers was developed and used with existing aerodynamic drag and lift data sets from wind tunnel tests. The aim of this research is to investigate the effectiveness and practical applicability of slipstreaming in ski-cross. Typical examples of gravity-powered sports, where several athletes are racing against each other, are ski-cross and snowboard-cross. The principles of slipstreaming or drafting are very well known in muscle-powered sports, but unknown in gravity-powered sports.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |