4 Reasons why wind tunnel testing is so important to race car aerodynamic development

Since Colin Chapman put wings on his Lotus 49C, an aerodynamic revolution stroke Formula 1 and later, the entirety of motorsport. Since then, much engineer brain matter is burnt on the unstoppable quest for downforce. Here is where the famed wind tunnel steps in. You will see it is good for much, much more than simple streamline visualization for pretty pictures like the main picture of this article and how it helped to reshape the way engineers, pilots and racing teams face aerodynamics, handling and lap speed (the supreme goal of motor racing).

1. It was the only technology available until very recently

Until computing prowess evolved to modern levels and really smart people figured how to simulate airflow in a computer (read more about it here , wind tunnels and track testing were pretty much what engineers had in their hand in the analog world. Hence, all racing cars until the mid/late 90’s had their aero designed almost entirely based on wind tunnel testing done first on scaled models .Sometimes, water tunnel testing can be done as well in order to obtain better results due to Reynolds number equivalency, meaning the model can be scaled down and tested on the same flow regime as the real deal.

2. It feels way more fun than simulating in a computer

Let’s be honest, making a CAD model, setting up boundary conditions and wait patiently for hours, days, weeks or even entire months just to get that results file will never be as thrilling (or real) as doing a real world experiment, consisting of real models and real fluids. Having some experience with both methods in my university, I can attest that a hands on approach may be more resource-consuming and provide less information, but the feeling of experimenting and seeing everything happeneng in front of you instantly is something way more exciting to do than sitting in front of a computer.

3. Computational Fluid Dynamics would never be a thing without wind tunnels

As numeric solutions for imputs will never be real world outputs, they won’t be worth anything until validated with help of a real, wind tunnel testing session. Simple as that, every CFD results file cannot be attested as precise until validated (i.e. proved empirically correct) with a wind tunnel/real racing experiment. This is one reason why Team Virgin’s attempt in F1 wasn’t as much of a deal as it seemed. Without any wind tunnel data to assure their results were correct, their end product lacked some aerodynamic traits needed for a competitive car (and also a too small fuel tank, but this is not the focus here.).

4. It is an intricate science which can provide extremely reliable data

Don’t you think doing wind tunnel experimentation on cars is a piece of cake. If done wrong, results can be extremely misleading and waste lots (with lots I mean a f@#%ton) of precious money which could be spent somwhere else with R&D, especially when a later stage version of a prototype is being tested. Also, fluid dynamics is one heck of a difficult subject to deal with. There is so much to be considered, even experienced engineers have trouble dealing with issues, such as having to move the ground beneath the car model so that it can perfectly replicate how cars cut through the wind on the road, as air is stationary relative to the ground almost all of the time or having to consider the perfect scaling of the car so the tunnel’s wall doesn’t have any effect on the tested object, and the list goes on. If everything is done correctly, results will be as precise as they can get, so it is a pretty rewarding sensation when a wind tunnel procedure turns out successful.

This is it, hope you enjoyed the read! Would you like to work in a wind tunnel? Do you think they are still relevant? If you have any comments or suggetsions, feel free to open your thoughts in the comment section. I have worked for some time with wind and water tunnels, so I am open to any questions as well.

Thanks for reading :)