Since last few years no one is building a wind tunnel because they are so expensive. McLaren and Force India are using Toyota’s wind tunnels because buying one or renovating their old ones are not worth the cost. The future of wind tunnels is clear. Many teams have already transitioned to using CFDs instead of the wind tunnel. CFD (Computational Fluid Dynamics) is the digital representation of flow conditions.
Speaking of their choice in Force India, the team’s Chief Technology Officer Andy Green said: “With CFD we get a better idea of what’s really going on in the car than the wind tunnel model. Previously, the ratio was 60:40 in favour of the wind tunnel, now it’s the other way round at around 70:30 for CFD. In the meantime, we rely heavily on CFD because you can see things on the computer that are impossible to see in the wind tunnel.”
Explaining further, he said: ” wind tunnel tests are costly. They cost time and tie up a lot of staff. There must be a change to the model for each modification.”
From road cars to motorsports
While many teams have created their own CFD software to match their individual needs, there are a few external providers. US-based Exa is the largest CFD provider for Formula 1. Automobile giants like BMW, Fiat, Chrysler, Ford and Honda use Exa software to create simulations for their road cars. Slowly, Exa has developed an interest in the motorsports side of the equation, especially since the speed of development is a lot faster in motorsports than road cars.
Exa supplies its CFD software to racing teams in Formula One, WEC, DTM, the US racing scene. They also provide a basic software called Powerflow for Formula E. BMW was the first customer to use Exa’s software in motorsport. They used it because a digital wind tunnel costs a lot less than a real one.
CFD simulations have shown that in the current cars, air turbulence behind the car reunites just where the front wing of the following car. This means loss of drive for the car behind and less grip on the tires as a result.
Formula One’s new owners have already used CFD data to figure out how to change the aerodynamic rules to reduce the dirty air so that cars can follow each other more closely. For 2019, the front wing and brake vents have been simplified as the first step towards improving the racing.
F1 is planning to implement a lot of aerodynamic changes via their 2021 regulation to improve overtaking.