A high-tech wind tunnel in Adelaide is Australia’s newest tool to help its Olympic cyclists gain a competitive edge.
Australia has not won a men’s Olympic cycling gold medal since 2004, in Athens, when Australian men won four. Australian women won three golds in Athens, but since then, Anna Meares has won Australia’s only Olympic cycling gold medal, in 2012.
If that wasn’t bad enough, over the same period, Australia’s old enemy, Great Britain, has won 21 cycling golds.
Presumably having seen far too many Poms on the podium, the South Australian Government, the South Australia Institute of Sport, and the Australian Institute for Sport are designing a wind tunnel at the Adelaide Super-Drome, where Australia’s top cyclists train.
Experts agree that a cyclist who uses a wind tunnel during training can take seconds, and maybe even minutes, off their time. Air resistance accounts for the vast majority of a cyclist’s energy expenditure and, in a tunnel, a cyclist can see how their body position, technique, clothing, helmet and bike cause drag.
Global competition
The Adelaide wind tunnel was first proposed in 2014. When it is built, it will be the only one of its kind in the world that is situated at a velodrome — a track cycling arena.
Flanders Bike Valley, a cycling centre of excellence in Beringen, Belgium, has had a cycling-specific wind tunnel since 2016. And earlier this year, former British gold medal-winning cyclist Chris Boardman opened a tunnel at his new performance centre in Evesham in the United Kingdom. Neither of these tunnels are based at velodromes, though.
“In a wind tunnel, a cyclist can make informed decisions from the live feedback they get and see the impact of their decisions in real time,” Boardman said.
Since he retired, Boardman has been a director of coaching for British cycling and now a policy adviser.
Andrew Warr, Performance Systems Manager with Cycling Australia, the sport’s national governing body, believes Australian cycling needs its own wind tunnel because existing tunnels in Australia are designed for motorsport.
Warr is a mechanical and electrical engineer who worked in motorsport in the UK for 20 years. He explained that although elite cyclists can use those tunnels, they are expensive to hire, not always available, and require a lot of equipment to be moved around and brought in.
“There’s not much space for a bike to sit in an F1 tunnel because of the rolling road that the race car needs,” explained aerodynamicist Rob Lewis of computational fluid dynamics company TotalSim. Lewis, along with Boardman and Kieron Salter of engineering consultancy KWSP, set up Sports Aero Solutions Limited (SASL), the company that designed the Evesham wind tunnel.
Warr envisages the working section of the Adelaide wind tunnel providing conditions as close as possible to those a cyclist experiences in an actual race.
“The spec we have is for a low-speed tunnel,” he said.
“We don’t need a rolling road or to be able to go 280 km/h.”
The tunnel will be similar to the two existing tunnels, both of which are open-jet, open-return wind tunnels, of the sort first developed way back in the 1920s by the US National Advisory Committee for Aeronautics, the forerunner to NASA. Most F1 tunnels are close return and close jet.
Warr said it’s important to get the right balance between high precision readings and realistic conditions.
“For the most reliable data, the athlete needs to be cycling — not under load, but rather as if he or she is free spinning,” Warr said.
“There’s some resistance; it’s like pedalling when the chain comes off.”
Salter adds that it’s the bike’s front wheel that must rotate, not the rear wheel.
“The mechanical mechanism takes the riders input and gives them the right amount of friction, so that translates as having the same speed as the rear wheel,” he said.
Warr said that he would like his coaches and analysts to be able to autonomously move the cyclist, while on the bike, by annotated control.
“Like they do in an F1 tunnel, as outside, the wind blows in different directions and often changes direction suddenly,” he said.
“Currently you have to stop the athlete, turn off the wind, move them, turn on the wind and start again,” he added.
“You can’t always be sure the bike is in the right position and this slows down testing procedure. Automation would help considerably, although it would be a big ask.”
Harm Ubbens, Flanders Bike Valley’s Project Manager for Aerodynamics, added the wind tunnel measurement platform is built into the actual tunnel and on a flat floor, so, if anyone wants to measure anything else, they have to take the platform out.
He explained the bike is clamped on the rig. The cyclist takes one turn in the tunnel and the analyst takes a baseline reading. Then the cyclist shifts to be more aerodynamically positioned on the bike, and they have another go. The measuring platform on which the cyclist sits floats on air bearings that offer no resistance to drag.
“If there’s space for a second measurement rig, next to the first, it is possible to measure the influence of a second rider on the first rider’s performance,” Ubbens said.
Salter explained that SASL engineers have designed a revolving platform that enables analysts to move the cyclist automatically while cycling in the tunnel, which is exactly what Warr wants.
Warr said the Adelaide tunnel will also need high-tech control and data systems to record the data generated by each cyclist and communicate it to them. Ubbens agrees, explaining that videoing the rider on the bike, in the tunnel, captures the rider’s contours and projects information to the rider so that the rider can see themselves as they move.
“This shows the cyclist in real-time how much their drag is changing when they adjust their technique,” Salter added.
Team effort
The Adelaide wind tunnel will be designed so that other sports can use it, not just cycling. This, Warr said, means that the tunnel will need bigger working sections than a tunnel designed just for cycling.
“You just need to change the fan speed up and down depending on how fast the athlete needs to move,” Salter said. And skaters and skiers already use the Flanders Bike Valley tunnel.
The plan is for the Adelaide wind tunnel to be ready by 2020. That’s too late for the Tokyo Olympics, held that year, but plenty of time for the new technology to have an impact on Australian cyclists’ performance by the Paris Olympics in 2024.
However, neither the Brits nor the Belgians are waiting around while Australia plays catch-up.
SASL is looking into ways to make its tunnel more automated. Ubbens is already talking to experts at the Delft University of Technology in the Netherlands about making further improvements to the Flanders tunnel. He is also designing a climate chamber to conduct tests on cyclists at altitude.
“There’s always a way to improve a wind tunnel,” he said.
This article was originally published as “Ride like the wind” in the November 2018 edition of create.