Wind tunnel gives Winter Olympics a gust of data

CHONGQING－A puff of freezing air burst out from a silver-colored streamlined tunnel spanning four meters, making a whizzing sweep over bifurcated, undulating fall lines on a miniature replica of skiing slopes.

This was part of an experiment carried out using a wind tunnel in Southwest China's Chongqing, as Chinese researchers attempted to figure out how turbulent airflow could affect Alpine skiers during the upcoming Beijing Winter Olympics.

Scientists from Chongqing University modified the device, which is normally used in infrastructure wind-resistance tests. It is capable of generating gusts of up to 35 meters per second, tantamount to a Grade 12 hurricane, to simulate the conditions encountered while skiing.

The airflow stirs a plume of smoke, emulating the whirling snowflakes set off by skiers rushing through, as repeated simulations were carried out.

When asked if this could be considered a steam engine employed to crack a nut, Li Shaopeng, a researcher with the university's wind tunnel lab, doesn't agree.

The instantaneous airspeed in Alpine skiing can reach 20 to 30 meters per second, which is graded ranging from gale to storm, Li says, citing the monitoring data.

"Skiers are at once affected by gravity, air resistance and lift forces, bracing power of the ground, snow friction, and skeletal muscle force," Li says.

Behind the sport lies an interdisciplinary science involving sports science, kinematics, flight mechanics, aerodynamics and mathematical optimization. "Securing better sporting performance comes down to a scientific problem," says Li.

This research team has been tasked with conducting the test since Chongqing is a mountainous city and the researchers there are adept at studying mountain winds, Li adds.

Yang Qingshan, the dean of the university's civil engineering school, says that the wind tunnel was used for wind-resistance tests for buildings and bridges. "This is the first time they have been used in competitive sports."

Researchers started by calculating meteorological data from February to early March in Beijing's Yanqing competition zone where the Alpine skiing competition will take place.

Thereafter, they gauged the localized airspeed and wind direction based on the data, before putting a lifelike mountain mock-up into the system. Eventually, they were able to ascertain data of the airspeed certain skiers are going to endure.

Li Ke, associate professor of civil engineering at the university, says that the data is provided to coaches so they can optimize training and achieve better results.

Xinhua