Modeling and analysis of Alpine skiing downhill based on the DPAS model considering four-way inhomogeneous environmental winds with digital twins at downhill course of the Beijing Olympic Winter Games

In Alpine skiing, the influence of the environment wind on the athlete is crucial. To accurately analyze the coupling effect of environment wind speed, wind direction, and the athlete's skiing process, this paper establishes the kinematic equations of the athlete based on Newtonian classical mechanics and computational fluid dynamics (CFD) and proposes a discretization method for the course. Simulation results were obtained by using CFD to obtain digital twins for the course and its surroundings. The simulation results were also used as input to the wind parameters to analyze the athletes' sliding performance. The Downhill Process in Alpine Skiing (DPAS) model was constructed to validate the actual downhill course in the Beijing Olympic Winter Games. An analytical framework for downhill skiing with way inhomogeneous winds was demonstrated to be a good simulation and validation of our analytical framework, proving its good simulatability and reliability. The downhill process is also subdivided into four phases: start-up acceleration phase, core acceleration phase, intermittent acceleration phase, and endurance sprint phase, based on the velocity-time curve derived from the actual course simulation. Tactical skiing strategies for skiers to improve their performance are proposed for the different stages of the process. We believe that the DPAS model can also be applied to other parts of Alpine skiing such as slalom, giant slalom, and super-G, and that the results can be used to suggest tactical strategies to improve performance.