CFD Simulation for sports

On December 12 2019, in Vienna, Austria, 34-year-old Kenyan Eliud Kipchoge made history by running a marathon in less than two hours. Eliud Kipchoge started running at 08:15 local time (07:15 am in Lisbon) after a “windbreaker” car and pacer and was constantly “escorted” by 41 top athletes, who in turn fulfilled the mission of hares.

For Kipchoge, hitting the two-hour barrier was more important than the world record set in 2018 in Berlin because it is a historic landmark and inspires a whole generation. “It’s different to race in Berlin and to run in Vienna. Running in Berlin is to win and beat a world record, Vienna is like going to the moon, “said the Kenyan, 2004 world champion and winner of the Chicago, London and Berlin marathons.

Meeting this challenge took months of preparation. Not only did all athletes have to be at the highest level, but all conditions and external variables had to be optimized. Part of this was due to a special arrangement of corridors that surrounded Kipchoge to reduce air resistance as much as possible. The superior performance of this training was achieved through tests performed on ANSYS Fluent simulation software and wind tunnel tests.

In a long distance race, aerodynamics plays an important role. The so-called hares serve not only to set the pace of the race but also to protect the center corridor from wind drag. A single hare can reduce air resistance in the second corridor by 50%. The formation in which these hares run determines the total reduction in air resistance that can be achieved.

In the previous attempt at Monza registration, hares raced in front of the athlete, reducing air resistance by about 70%. To further reduce this, more than 100 formations were analyzed using computer simulations using ANSYS Fluent. Against everyone’s expectations, the inverted V-formation with five to seven hares in front of the athlete and two to three behind him proposed by Robby Ketchell turned out to be the ideal variant. This reduced Kipoche’s air resistance by 85% compared to a hares-free runner.

In addition to the formation of hares, the researchers also observed the distance between the hares themselves and between the hares and the athlete. The effect of a cyclist next to the athlete (who provided him with food and drink) was also tested in the wind tunnel, as was the effect of a car driving in front of the hares with a large clock showing race times.

This project, which was part of the INEOS 1:59 Challenge, was carried out on behalf of INEOS and in collaboration with Robby Ketchell (AvantCourse), Team INEOS and Global Sports Communication. Wind tunnel tests were performed at TU Eindhoven wind tunnel. The computer simulations of KU Leuven and TU Eindhoven were performed using ANSYS Fluent software.

This milestone in sports history has only been possible by combining tremendous physical capacity with optimization through simulation. These are examples that allow us to look at the future of humanity and realize that it is within our power to create the most advantageous solutions for everyone: producers, customers and the planet!