The largest CFD modeling in the World

  • July 08, 2018

Researchers conducted the first aerodynamic simulation of the complete peloton of road bikers, which brought unexpected results.

 The idea is to optimize the amount of energy spent during the race to maximize team performance, especially for elite team racers. Thus, pelotuns are the basis for most of the strategy around these competitions.

The largest CFD modeling in the World

It was believed that racers in the middle of the peloton can save from 40 to 50 percent of their energy compared to a lone cyclist due to reduced air resistance. This was based on fairly simple mathematical models without the use of digital modeling. However, anecdotal information from real riders showed that the decrease in resistance is much greater.

As it turned out, they were right.

Simulations conducted by Professor Bert Blochen of the Eindhoven University of Technology and Kew Löwen on the Cray XC supercomputer under the ANSYS Fluent CFD software showed that air resistance is only 5-7 percent of the resistance of a solo cyclist - an order of magnitude smaller than a simple calculation . This makes it four times lighter than the pedal in the middle of the peloton than if you are riding the bike yourself.

Aerodynamic modeling simulated a complete peloton of 121 cyclists, containing three billion cells. To obtain accurate data on the resistance of air, the calculations were carried out to within 0.020 mm from the surface of the rider and bicycle. In the calculations, a total of 108 hours of supercomputer were used in 13,824 processes. According to ANSYS and Cray, this is the largest simulation of fluid dynamics using commercial software, as well as the world's largest aerodynamic modeling.

The simulation showed that the lowest resistance is observed in lines 12 to 14, but they also found that everyone, even the leading cyclist, received some benefit from being part of the peloton. Below are the various abbreviations for air resistance (compared to a single rider).