The aviation technology behind ski jumping

 Among the wonderful ice and snow sports at the Beijing Winter Olympics, ski jumping is an extreme winter Olympic sport that combines speed, strength and courage. It is very popular among ice and snow enthusiasts from all over the world for its long jumping distance and graceful movements. The wind in nature is a ski jumper's closest partner in training and competition.

"Different environmental winds, different movement speeds, different body weights, and different flight attitudes will produce corresponding air changes. This is what professionals call aerodynamic characteristics." Aviation Industry Corporation of China Limited Air Yuan Li, president of the Power Research Institute (hereinafter referred to as the Aeronautical Industry Aerodynamics Institute) and China Ice and Snow Science Advisor, told the Science and Technology Daily reporter.

Yuan Li told reporters that after more than a year of wind tunnel-assisted training and computational fluid dynamics research, the Aeronautical Industry Institute of Aeronautics used aviation wind tunnel technology to make a historic breakthrough in the performance of Chinese ski jumpers. The athlete won the first place in the sub-station for the first time in the international points competition, and finally the Chinese ski jumping team got 3 "admission tickets" to the Beijing Winter Olympics.

A wind tunnel is an artificial way to generate and control airflow to simulate the flow of gas around an aircraft or an entity. . The basic principle can be understood as "objects move, air does not move" in the real movement process, and "air moves, objects don't move" in the wind tunnel, and then simulate the aerodynamic characteristics generated by the mutual movement between air and objects.

"Using the wind tunnel, parameters such as force, speed, angle and rotation speed during the movement can be obtained, and then the optimal posture of the equipment manipulation and body can be analyzed and determined; through the flow display technology, the air flow characteristics around the test object can be visualized, Analysis and interpretation are more intuitive and convenient." said Wang Chongli, a technical expert at the Aeronautical Institute of Aeronautics and Astronautics and a Chinese ice and snow scientist.

In 2019, after learning that Chinese platform jumpers had to make a special trip abroad for wind tunnel training every year, the time and economic cost were extremely high, the Aeronautical Industry Aerodynamics Institute took the initiative to cooperate with the General Administration of Sports of China to use the principles of aero-aerodynamics to cross the border. Two types of sports-specific wind tunnels have been tailored for the Chinese ski jumping event. Among them, the comprehensive sports wind tunnel built in Laiyuan is the largest and most comprehensive sports aerodynamic test among similar wind tunnels in the world. facility.

Ski jumping and wind tunnel technology have collided brilliantly. During the wind tunnel training of the National Ice and Snow Team for more than a year, the scientific and technical personnel of the Aeronautical Institute of Aeronautics and Astronautics have been accompanying the ice and snow athletes, fully communicated with the National Ski Jumping Team, and formed a systematic scientific training plan from skiing, take-off to flight. .

"During the ski jumping assist and take-off process, the athlete's snowboard slides down the fixed U-shaped snow track at high speed, and the force of the footsteps is different, which will cause the snowboard to inevitably rub against the snow track on both sides, which in turn leads to the sliding speed. Wang Chongli said that through wind tunnel training, under simulated relative wind speed, the force of the athlete's feet and the frictional resistance of different postures can be accurately measured by the instrument in the force measuring platform to comprehensively evaluate the force of the athlete's footsteps. Situation and take-off angle, thereby improving the assist and take-off posture, and increasing the speed of the launch.

"Lifting" is an important training in ski jumping. When the wind speed is given in the wind tunnel, the super-large "fan" starts to run, and the athletes are lifted into the air under the traction of the safety rope, and the relative airflow gradually rising in the wind tunnel gives the athletes aerodynamic lift. "When the athlete is in a state of balance between aerodynamics and body gravitational force, the athlete can make a ski jumping aerial flying posture, and can safely try to adjust the body posture in the wind tunnel to experience the impact on the body balance and effectively improve The athlete maintains the best posture in the air to control the balance ability of the snowboard." Wang Chongli said.

According to Yuan Li, in addition to wind tunnel assistance for scientific research and training, another core technology of the Aeronautical Institute of Aeronautics and Astronautics, Computational Fluid Dynamics (CFD), also provides a more effective means of assistance for ski jumping research. The members of the national ski jumping team carried out the three-dimensional modeling of the assist and flight attitude. Because of the computer simulation method, they can obtain the information of the body flow around the athletes and the air pressure of each part of the body. The lift and resistance analysis can identify the main factors affecting sports performance, and provide a quantitative reference for the national team to optimize technical actions.