What Is The Beam Wing In F1? (Fully Explained)

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The beam wing was one of the key implementations of F1’s major rule changes in 2022. It’s an important aerodynamic device for dealing with the issue of dirty air, but what exactly is the beam wing on an F1 car?

The beam wing on an F1 car is a small wing at the back of the car under the main rear wing, designed to push ‘dirty air’ up and over the car behind. This is designed to minimize the effects of dirty air for the car behind, making the cars easier to follow and overtake during a race.

The beam wing has a very important job on modern Formula 1 cars. Besides reducing the amount of dirty air for the car behind, the beam wing is also crucial for rear downforce and allowing the diffuser to do its job properly. Below, I’ll discuss the beam wing in more detail and why it’s so important.

Note: First, I’ll explain what exactly the beam wing is and how it works, but then I’ll give a more detailed explanation of why it’s needed and how dirty air affects F1 cars. This will make it clearer why the beam wing is such an important component of modern F1 cars!

Beam wing at the back of an F1 car, with arrow and box showing its location underneath the rear wing.
Here is the beam wing on a Red Bull F1 car, sitting underneath the main rear wing

What Does The Beam Wing Do In F1?

The beam wing on an F1 car is designed to help the car produce more downforce, and also to deflect a lot of the dirty air up and over the cars behind. The beam wing sits underneath the main rear wing, on either side of the exhaust, acting almost like an extension of the diffuser.

This means the beam wing on a modern F1 car plays no role in directing air either from the exhaust itself or onto the rear wing to enhance downforce. But it does deflect a lot of the dirty air coming off the car (more on that soon) and it plays a key role in producing downforce.

Beam wing on an Aston Martin F1 car with a box and arrow showing its location below the rear wing and exhaust.
Here is the beam wing on an Aston Martin, again showing its location under the main rear wing and the exhaust

Air flowing over the beam wing will lead to some downforce generation, but the primary downforce function is really to act as an extension of the F1 car’s diffuser at the back of the car. The beam wing helps create an area of low pressure at the top of the diffuser, helping ‘suck’ more air under the car, boosting downforce through the ground effect, and making the diffuser more effective.

Deflecting The Dirty Air

But the air that flows over the rest of the car, from the front wing and over the sidepods all the way to the beam wing, is also then deflected up and – ideally – over the cars behind.

It’s not a perfect solution though, as not only does the car still produce some outwash (essentially dirty air that doesn’t flow directly over the car and instead goes largely out to the sides), but the dirty air that does go off the back doesn’t just catapult into the sky never to come back down.

The wake at the back of the car (a bit like the wake left behind a boat in water) is shaped like a teardrop. This means some of the dirty air ejected up by the beam wing does fall back down to the car behind. However, the beam wing does reduce the amount of dirty air the trailing car must deal with, and so its downforce components aren’t hampered as much as they could be, ideally making it easier to follow each other and providing more overtaking opportunities.

How The Beam Wing Helps With Downforce

The beam wing is also very important aerodynamic device. Along with directing some of the dirty air up and over the car behind, it also causes the entire rear of the car to work as one. Like a ‘normal’ wing, it generates high pressure on its upper side and low pressure on its lower side (more on how this generates downforce later).

This low pressure area is above where the diffuser returns the low pressure air coming from the underbody to the higher ambient pressure by expansion. Since high pressure air always flows toward low pressure areas, this causes the angle of attack of the diffuser to increase, which causes the airflow to accelerate and flow more upward.

Both of these effects cause the diffuser to ‘pull’ more air under the floor and ‘work the floor harder.’ The low-pressure zone below the main rear wing’s lower element also has the same effect on the beam wing, making the beam wing the link that makes each part of the car’s rear end work as one.

When Was The Beam Wing First Used In F1?

The beam wing with its current function was first developed in F1 in 1985 by Rory Byrne for his Toleman TG185. It was intended to regain downforce that had been lost due to the ban on twin rear wings. The beam wing concept was slow to gain traction across the rest of the grid.

However, after ground-effect cars were banned, and as people in F1 began to better understand how to maximize downforce using flat-floors and diffusers, more teams began to implement the beam wing design into their cars to help with rear downforce production, which ultimately made the cars faster in the corners.

In 2014, the beam wing was banned from Formula 1. This was ultimately done to reduce rear downforce on the cars and improve the racing. In its place, the teams could instead use two vertical beams to support their rear wing, as these would not have any benefit to the rear downforce being generated by the car. The T wing then appeared in 2017, but this was different from the beam wing.

So, the beam wing was originally used largely for downforce production, but in their modern form, dirty air is the key phrase you’ll hear associated with them. Let’s explore dirty air in more detail to understand why the beam wing returned in 2022.

How The Beam Wing Helps With Dirty Air

Dirty air in F1 is the turbulent air that comes off the body and aerodynamic devices on a Formula 1 car. In order to create massive amounts of downforce, the various wings and pieces of bodywork on the car interact with and disrupt the airflow, which creates turbulent, low-pressure air behind the car, also known as dirty air.

Bernoulli & Venturi

In order to understand what dirty air means, you need to understand how downforce is generated. To do that, we need to discuss the Bernoulli equation and the Venturi effect. In simple terms, Bernoulli’s equation (named after Daniel Bernoulli) says that along a streamline with increasing flow velocity the static pressure decreases. So, the faster the air flow, the lower the pressure.

This was proven in 1797 by Giovanni Battista Venturi. Using a pipe that narrowed and widened, he found that the flow velocity of a fluid passing through a pipe is inversely proportional to the changing cross-section of the pipe. In other words, narrowing the pipe sped up the fluid going through it.

Venturi was also able to demonstrate experimentally that the static pressure at the constricted sections was lower than at the wider sections. He therefore proved Bernoulli’s equation that pressure decreases as the fluid’s speed increases. At the same time, he demonstrated what is now known as the Venturi effect and the Venturi nozzle, which is still used today in many fields.

The final piece of the physics puzzle we need to understand for downforce production is the continuity equation, which essentially tells us that the same amount of a fluid (air is a fluid) that flows into a constriction comes out again at the other side. In order to do this, it must go faster, which we know lowers its pressure.

But what does this have to do with an F1 car?

Applying This To F1

Well, if you look at the underside of an F1 car it’s actually shaped like a kind of Venturi nozzle. The air enters a constriction, which accelerates it and lowers its pressure. At the back of the car, where the diffuser effectively widens the floor again, the air exits.

So, a low pressure area is created under the car, while the pressure above the car remains higher. This is similar to how a suction cup works. When you press a suction cup down on a surface, you create a low pressure area underneath it, and the atmospheric pressure around it is higher, ‘pushing’ the suction cup into the surface.

But F1 cars don’t just generate downforce via their floors, although the complex shapes underneath are indeed major downforce generators even since before the 2022 regulation changes. If you look at the wings on the car, you notice that the bottom side is longer than the top because of its shape.

According to the continuity equation, the air on the bottom has to flow faster and so there is lower air pressure on the bottom while there is high pressure on the top. This pressure difference pushes the car towards the ground, which we know as as downforce.

But how does this create dirty air? And how does the beam wing help with this?

How Dirty Air Is Created

Through these interactions and the creation of pressure differences, the various components on an F1 car (like the floors and wings) interact with and disrupt the airflow. When air flows over an aerodynamic device it loses energy and slows down. This low-velocity flow leads to the formation of turbulence, and by the time the airflow makes its way towards the back of the car, it has turned into a hot, inconsistent mess of air.

This is great for producing downforce on the lead car (as it ‘uses up’ the air’s energy to do so), but it interferes with the air left behind the car – the air that following cars must travel through. We can think of the energy of the air as the air’s total pressure (static + dynamic), and its dynamic pressure is the part related to velocity.

This turbulent, low-energy air behind an F1 car isn’t as good at generating downforce as ‘clean’ undisturbed air is. To generate maximum downforce, an F1 car needs the air to all flow over the car cleanly in one direction. Turbulent air doesn’t allow this, reducing the effectiveness of the downforce producing parts on F1 cars that are in the wake of another car’s dirty air.

Why Is Dirty Air Bad For Formula 1 Cars?

Dirty air coming off a Formula 1 car can affect a trailing car up to three or four seconds behind. When the following car is within this range, they begin to lose downforce and grip, which makes them slower than the car in front. Drivers obviously need to be faster than the car in front in order to be able to overtake, and so dirty air inhibits overtaking.

So, the goal of the beam wing is to direct a lot of the dirty air that the car produces, primarily via its wings and other over-body downforce-generating components, up and over the back of the car, ideally over the trailing car as well. I’ve discussed above that it is of course limited, and it doesn’t affect air coming out of the exhaust or to the sides of the car, but it still definitely helps reduce the amount of dirty air directly behind the car.

Cooling The Car In Dirty Air

Another side effect of dirty air is the cars begin to struggle to keep their temperatures down. Formula 1 cars are carefully built to collect oncoming air to cool the brakes and the engines, but with hot and turbulent air coming off the car in front, the trailing car can struggle to get enough cool air into the sidepods and other air intakes, creating overheating issues.

Note: For more on how this works, check out our article all about F1 car cooling systems

The beam wing can help reduce the dirty air coming off the back of the car, but as it sits to the sides of the exhaust, it doesn’t affect the hot air coming out of that. So, it’s not a perfect solution, but it’s a step in the right direction for closer racing.

Final Thoughts

The beam wing on an F1 car does help the car produce more downforce, but it also deflects the dirty air produced by the car’s body up and over the car behind. This reduces the amount of dirty air trailing cars must travel through, which helps the cars follow each other better.