Taking on alpine skiing? Wind tunnel 3D modeling to help

Light a cigarette, the wind starts to blow. In the wind tunnel of the structural laboratory of Chongqing University, in front of the alpine skiing track model, you can clearly see the smoke floating chaotically with the wind. This is the research site of the wind environment of the ski resort. What is the use of this for athletes in the competition? As the Winter Olympics is approaching, a reporter from Science and Technology Daily went to Chongqing University to explore the "technological style" behind the alpine skiing project.

Video production: Yong Li, Shan Qianlan, Zhou Wenwen

Helping to Challenge the "Crown Jewel of the Winter Olympics"

Alpine skiing is one of the fastest and most dangerous events on the ski slopes, and is known as the "crown jewel of the Winter Olympics". It originated in the Alps region of Europe, also known as Alpine skiing, and was gradually developed on the basis of cross-country skiing. It has been listed as a Winter Olympic event since 1936. In this competition, athletes use potential energy to slide from the top of the mountain to the finish line at the bottom of the mountain. The winner is the one who takes the least time.

In the upcoming Beijing Winter Olympics, there will be an alpine skiing downhill competition. However, due to the climate, skiing equipment and venues in my country, this sport emerged relatively late in my country and has not developed very fast. The "Technology Winter Olympics" special project in which Chongqing University participated focuses on the research of the wind environment in the ski resorts, providing decision-making basis and support for Chinese athletes and coaches.

Yan Bowen, an associate professor at the School of Civil Engineering and a member of the Chongqing University "Science and Technology Winter Olympics" team, established a practical, efficient and accurate downhill model for alpine skiers through field surveys and 3D modeling.

"Our team went to the Winter Olympics venues four times for inspection. By reasonably simplifying the track of the National Alpine Skiing Center in the Yanqing competition area, we established a real track model and incorporated the previously established straight + curved alpine downhill sports model." Li Ke, a member of the "Science and Technology Winter Olympics" team of Chongqing University, introduced that at the same time, combined with the numerical simulation results of the track wind field and limited measured data, and considering the influence of ambient winds in different directions on the venue, an environmental model for alpine skiing downhill was established, creating a more comprehensive and effective alpine skiing downhill model.

The track model in the wind tunnel experiment. Photo by Yong Li, a reporter from Science and Technology Daily

Wind tunnel 3D modeling helps athletes tailor training plans

The wind tunnel laboratory of Chongqing University used to conduct tests on large fixed structures such as buildings and bridges. This is the first time that it has conducted tests on athletes.

It is understood that factors that affect athletes' sliding include the athlete's body shape, skills and tactics, track conditions, snow conditions, wind speed, and the characteristics of ski equipment. During the sliding process, athletes are affected by gravity, air lift and resistance, ground support and friction, and skeletal muscle force, among which air resistance has a great relationship with the athlete's posture. According to monitoring data, the wind speed in the stadium can reach more than 20-30 meters per second, so the direction of the wind speed in the stadium environment will also have a great impact on the athlete's sliding.

"The first part of our work is to study the wind environment, of which about 70% is done through computers. We first simulate the wind environment of the entire earth through computers, and then simulate the wind environment of a specific area to collect data for subsequent research," Li Ke introduced.

The experimental site. Photo by Yong Li, a reporter from Science and Technology Daily

In addition, it is necessary to study the relationship between wind and force. "Only by knowing the force can we understand the sport, and to know the force, we have to conduct mathematical modeling. We need to build a downhill model for athletes to study what kind of force and wind load the athletes are subjected to when they adopt different postures." Li Ke introduced that this research will assist coaches in customizing personalized scientific training programs for each athlete that integrate tactics, equipment and physical fitness to improve competition results. "They sincerely hope that the national team members can achieve good results in the competition!"

Source: Science and Technology Daily

◎ Science and Technology Daily reporter Yong Li and intern Shan Qianlan

Editor: Zhang Qiqi

Reviewer: Wang Xiaolong

Final judge: He Yi