Voxdale: CFD in Sports

By Joren Bastiaens

Making an impact with CFD in Sports

Voxdale - CFD in Sports

Here at Voxdale, a vibrant design and engineering company based in Belgium, we believe that sport and technology go hand in hand. Particularly when you are looking for those marginal gains that can make the most impact; the difference between winning and losing. By using Simcenter FLOEFD™ technology, CFD (Computation Fluid Dynamics), we have always been at the forefront of technological innovation, especially in the sports performance industry.

Fasten your helmet

Sports, for us, are all about emotion. Last year’s Maillot Jaune deciding time-trial at the Tour de France, is still fresh in the memory of many cycling fans. In this timed stage, Roglic lost what looked like a certain victory as his rival Pogacar took over the lead overall classification at La Planche des Belles Filles. Immediately after the stage finished, Roglic’s helmet was a point of debate. Did the Slovenian rider experience an unlucky off-day? Or could the position of his helmet have been the reason for his downfall?

The helmet alone could not have been the only cause of the difference between the two riders. Both pro-cycling team Jumbo-Visma and helmet manufacturer Lazer carried out multiple experiments to improve the aerodynamics of their star rider and his equipment. With the help of Voxdale, Lazer altered the helmet design, improving the aerodynamics. The outcome of this optimization was evident in the Men’s Time-Trial at the Tokyo Olympics earlier this year. Roglic took the gold medal!

Sleigh bells

One positive outcome of the Covid pandemic is that there will not be a year off from the Olympic games. The Winter Games will now take place next year, in 2022, great news for sports enthusiasts! Voxdale has been working together with multiple national bobsleigh teams for a few years now, developing and optimizing the equipment that the athletes use.

After pushing the bobsleigh to 40 km/h on only 50 meters of ice, gravity takes over as the accelerating force. From that point onwards, it is mainly aerodynamics that determines the bobsleigh’s speed. To achieve maximum performance, we used Simcenter FLOEFD to optimize the design of the bobsleigh. Working to minimizing the frontal surface area and the drag coefficient. CFD is a very powerful tool to compare different concepts during such a design phase, as we can visualise and study the flow structures in detail. At the same time, it is possible to conduct the experiments while approximating the demanding conditions. Eg. low temperature and high speed, which would otherwise be difficult in real life.

Voxdale - Bobsleigh

Bernico uses CFD to Ride the waves

It’s only a small step to go from ice to water, especially in CFD! Bernico International builds custom powerboats for recreational activities and racing. For the concept of their new racing boat, the company turned to Voxdale to establish the final design and achieve the highest level of performance.

Optimizing the aerodynamic efficiency of a racing boat is challenging, because of the combination of fluid dynamics above and below the water level. For this particular problem, the engineering team at Voxdale used the Free Surface feature available within the Simcenter FLOEFD software. This allowed the engineers to investigate the wake progress behind the boat and optimise the hull in a real-life situation.

Voxdale - Bernico

Using the digital twin

Voxdale has a rich history of using CFD in sports performance, especially in cycling. Did you know that some of the quickest bikes in the pro peloton are developed in Belgium, with the help of Voxdale? Together with the R&D department of Ridley, one of Europe’s leading bicycle manufacturers, we worked on a new bicycle frame, optimized for road racing.

When riding above 45km/h on a flat course, 90% of the total cyclist energy goes into overcoming aerodynamic resistance. Since there is a quadratic correlation between drag and velocity, these two factors mean that it is absolutely vital to optimize the equipment of athletes to be as aerodynamically efficient as possible.

The design process of this new bike was the perfect illustration of new and existing technologies coming together. Voxdale started out by making a digital 3D bike, to analyse and optimize it using CFD. Cycling in a perfect headwind is not realistic. Using Simcenter FLOEFD made it possible to simulate airflow coming from several different angles of attack. We can then analyse its effects on every part of the bicycle in detail. During the CFD design phase, some essential features were established giving the Ridley Noah Fast the advantage over its competitors.

The next stage saw the CAD model being brought to life by using 3D printed parts to create a full-scale wind tunnel model. The initial simulations were validated in real life. After some final formal adjustments, Ridley was able to start production of the frame.

Noah Ridley

CFD in Sport to create the perfect bike

Using CFD in a project like this is a game-changer. Aerodynamics is all about interactions, especially in cycling. Think about riders experiencing less resistance when riding together in a peloton. Or that perfect combination of one specific helmet making a seamless transition onto the athlete’s back. By using CFD, the focus can be kept on the bigger picture. Each part of this specific bike was optimized to work together with the rest of the frame. The handlebar combination transitions seamlessly into the top tube. Also, the bottom of the down tube has a specific trip-wire design, so the quartering wind glides over the frame to reduce drag.

The frame has since been optimized for unpaved roads, and now stands as one of the fastest gravel bikes on the planet!

These are just some of the ways that we have use CFD in sports. We have many other applications that we cover, such as Medical Technology, Consumer Products. However, projects that emote the joy that we get helping athletes achieve their dream, well those are just the best!

CFD in Sports – Further reading

For more stories on CFD in sports, take a look at these other fun projects that we’ve completed:

Some other great sporting stories, make sure you take a look at these:

This article first appeared on the Siemens Digital Industries Software blog at