The simulation results confirm that the best position is in the core of the peloton close its head, row 12 to 14; but the computer models surprisingly calculates that the drag experienced by the athletes in this position is 10 to 20 times less than for an isolated cyclist; so far the scientific community considered that the drag was only 2 or 3 times smaller in the peloton.
While biking, cyclists push air in front of them creating an over pressure (in red) and a depression in its back (blue); this air resistance that the athlete continuously has to fight is known as the drag. Because of the aerodynamic interactions with the surrounding cyclists, the athlete at the center of the pack is literally entrained by the peloton induced air motion. Using ANSYS Fluent running on a Cray, the largest computer model ever done with 3 billion cells to accurately predict the flow pattern in between each cyclist of the peloton enables Professor Bert Blocken to create a complete map of the drag experienced by all cyclists. Compared to the drag of an isolated cyclist the air resistance experienced at the core of the peloton is reduced by up to a factor 20 - down to 5% of an isolated cyclist: it is approximately 4 times easier to bike at the core of the peloton than alone.
"We are closely collaborating with elite athletes who want to benefit from advanced technology. These results teach them how important it is to stay well sheltered in the peloton as long as possible: you save a lot of energy and remain fresh until the final rush of the race", explained Professor Bert Blocken, TU/e and KU Leuven. He added: "These results were so surprising that we also set up a wind tunnel test and successfully validated the numerical results with the largest wind tunnel experiment we have ever done."
"Supercomputers handle the most challenging simulation, analytics and AI workloads imaginable", stated Dominik Ulmer, Director of Operations in EMEA at Cray. "Because Cray systems deliver extreme scalability and performance, they are essential to gaining better understanding of complex problems."
"In a time when simulation is crucial to accelerate and amplify innovation for High Tech industries, the peloton project and is surprising results illustrate that this simulation technology is truly pervasive and can make a huge difference in a popular sport such as cycling", concluded Thierry Marchal, Global Industry Director for Sports and Healthcare at ANSYS.