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What Is Dirty Air In F1? How Does It Affect The Cars?

The 2022 Formula 1 season saw some of the biggest rule changes in the history of the sport. The aerodynamic shape of the cars changed in order to reduce the amount of dirty air in the wake of the cars. But you might be wondering what exactly “dirty air” is in Formula 1.

Dirty air refers to the air coming off the back of an F1 car. This air is hot and turbulent as it has passed over the body of the car. The car behind will have less downforce in dirty air, as the turbulent air is less efficient for producing downforce. Clean air is ideal for aerodynamics.

The rule changes have improved the dirty air problem that Formula 1 has experienced for many years, and it has made the cars much easier to follow. However, there is still some dirty air that comes off the back of the cars, and we go over what causes this in more detail below.

What Is Clean Air In F1?

Clean air is the ideal situation for a Formula 1 car’s aerodynamics. Clean air is undisturbed and can easily move along the F1 car’s body and through the air intakes. This allows cars to produce maximum downforce in clean air, and cool their internals more efficiently.

As the clean air passes over a Formula 1 car it pushes the car into the ground, through the effect known as downforce. With the 2022 aerodynamic rule changes, the air is also pulled in through the Venturi tunnels underneath the floor of the car, and this produces even more downforce.

Clean air is better in Formula 1 as each aerodynamic part of the car can be influenced by the airflow passing over it, which means that the car will be producing the maximum amount of available downforce in clean air, allowing it to go faster around corners.

Producing Downforce

In order to produce downforce, F1 cars need an area of high-pressure air above them and an area of low-pressure air underneath. It’s this pressure difference that causes the car to be ‘pushed’ or ‘sucked’ towards the ground.

In clean air, when a car doesn’t have another one in front of it, it’s easy to generate this pressure difference as there is a lot of air in front of the car in a fairly uniform arrangement and of pretty constant density. But when this air is moving around chaotically, or turbulently, the car isn’t able to generate as much downforce as before. This is the issue of dirty air.

What Is Dirty Air In F1?

Dirty air refers to the wake of a Formula 1 car. Dirty air is what makes Formula 1 cars difficult to follow, as the cars are not able to produce as much downforce when dirty air flows over the top of them. The main focus of the 2022 aerodynamic rule changes was to make the cars easier to follow.

Once the air passes over the Formula 1 car it becomes turbulent. This is because the clean air is used to push the car into the ground. The various wings and other components on the car disrupt the air as it flows over the car, and this leaves a trail of dirty, turbulent air behind the car.

Because this air’s density is far less uniform than that of clean air, and it’s all moving around far more chaotically, the trailing car basically can’t make as much downforce out of it. Essentially, there is a less ‘reliable’ source of air to create that all-important pressure difference for generating downforce.

In addition, the engine of a Formula 1 car is extremely hot, and hotter air is worse for aerodynamics as it’s also very turbulent. The heat from the engine is naturally ejected at the back of the car, and mixing this hot air with the turbulent air coming off the wings makes for even dirtier air. It also makes it harder for trailing cars to cool their internal components too.

What Causes Dirty Air?

Dirty air is caused by an F1 car moving through clean air and disrupting it, making it turbulent. With all the wings and various other downforce components on an F1 car, the air is greatly disturbed, and because F1 cars travel so fast the wake of dirty air is measurable even several seconds behind.

Dirty air is caused by a car moving through clean air. It’s difficult to imagine since we can’t see how air moves when a car goes through it, but it’s exactly the same as how a boat moves through the water. The handling of the cars is affected in much the same way too.

When a boat moves through the water you can see the wake behind it. The wake behind a boat is exactly like the “dirty air” or turbulence that you would find behind an F1 car as it moves through the air. The wake is simply caused by the boat moving through the water, disturbing it as it does so.

If you add little winglets and change the shape or size of the boat, you can change how much of a wake follows behind it. This also changes how far the wake extends behind it. Formula 1 cars work in the same way when it comes to dirty air and the wake that they have behind their cars.

The previous generation of cars used complex wings with unique shapes and different aerodynamic parts on their body. This gave the cars more downforce, but it also left a massive wake behind them with a long trail, meaning that cars behind them were not able to follow closely, and even those several seconds behind would lose some downforce.

How Does Dirty Air Affect An F1 Car?

Dirty air is not good for a Formula 1 car. We know that F1 cars are slower when they are following in the wake of another, but why exactly is that the case? It all comes down to the downforce that the trailing car is capable of producing while driving on the track.

The biggest strength that a Formula 1 car has is the massive amount of downforce that it can produce. Formula 1 cars produce more downforce than any other racecar on the planet, and this is what makes them so incredibly fast across an entire lap. Nothing can beat the cornering speeds that Formula 1 cars can reach.

Formula 1 cars can take some corners at 190 miles per hour, and the faster you go, the more downforce the car can produce. However, the car needs clean air in order to produce that downforce.

When the car loses some of its downforce behind another car, the driver has to ‘fight’ the car more to remain in control. They may start sliding slightly in the corners, which makes the tires wear faster, and because they aren’t getting as much cool, clean air into their air intakes, the car can begin to overheat too, forcing them to back off.

F1 Slipstream vs Dirty Air

Dirty air is not always bad for Formula 1 cars though. When it comes to the straights, less drag and downforce is better. This means that the same turbulent air that disrupts the car through the corners can actually benefit the trailing car on the straights.

A slipstream in F1 is when one car follows closely behind another car, allowing the following car to gain speed without having to ‘work’ harder. Slipstreams are incredibly powerful in Formula 1 because of how the car’s aerodynamics work, so the following car could easily gain more than 10 mph in a slipstream on a long straight.

Slipstreams work when the lead car ‘punches a hole’ in the air for the car behind, leaving behind them an area of lower pressure, less dense air. The car behind, when tucked in behind the car ahead of them, has much less air resistance that it needs to cut through, which means that it can hit a much higher top speed than it could in cleaner, denser air.

Slipstreams are not always powerful though, and the cars often need a long straight in order for them to work. On circuits with shorter straights, such as the Red Bull Ring and Albert Park, the slipstream is not as effective as on circuits like Monza and Spa.

How Do The 2022 Rule Changes Improve Dirty Air?

The goal of the massive overhaul in the aerodynamic rules in 2022 was to reduce the amount of dirty air in the wake of the cars. This would ultimately make the cars easier to follow closely and allow for more overtaking opportunities without the use of long straights and DRS.

There are two main elements to the process behind reducing dirty air in Formula 1. The first is to use a more uniform and simplistic body shape. Removing all the winglets and bargeboards from the cars and creating simpler wings allowed for a smoother transition in airflow and cleaner air off the back of the cars.

Secondly, the cars were built to generate most of their downforce using the floor by building Venturi tunnels into the floor as opposed to the flat floors that we have seen in the past. This means that some of the most important air flow comes from the bottom of the car, the air that is being funneled into the floor.

In order to direct dirty air away from the floor of the trailing car, a larger beam wing was brought in. The beam wing is the smaller wing underneath the rear wing, and the goal of the beam wing is to direct the dirty air up and over the car behind, leaving more clean air available to funnel into the floor of the car behind.

The 2022 Regulation Changes

When the 2021 cars followed each other within about 20 meters the estimated downforce loss was 35%. This meant that the trailing cars couldn’t reach their theoretical top speed in the corners as they lost some downforce and would have to trail further back just to stay in control of their car at these speeds.

The 2022 regulations aimed to reduce this effect substantially, and early estimates suggested that the downforce loss that was once 35% is now just 4%. However, the closer the cars get (to a certain extent) the more powerful the dirty air effect becomes, and it is an unavoidable consequence of open wheel racing.

Is Dirty Air Still A Problem In F1?

The dirty air that comes off the back of a Formula 1 car has significantly improved in 2022 following the big rule changes that were implemented. However, it is still somewhat of an issue in modern Formula 1, and the cars are still not great at following one another closely.

We have seen that it has become much easier for the cars to follow each other more closely, especially when we look closely at the various battles that we have seen on track. Some of the overtakes that have been pulled off in 2022 would have been nearly impossible in 2021 and earlier.

The main difference that we are seeing is that drivers now have the ability to fight back when they are overtaken by another car. In the past, a driver had to back off as soon as they had been overtaken because of the huge loss of downforce that they would experience in the wake of the car ahead of them.

However, as saw with Max Verstappen and Charles Leclerc at the early part of the season, battles can rage on for several laps and drivers don’t quickly fall back in order to regain their grip. It’s a positive sign, but more work needs to be done and the cars need to be tweaked more in order to promote further overtaking opportunities in Formula 1.

Final Thoughts

Dirty air in F1 makes it difficult for cars to follow each other, and for many years it has prevented cars from overtaking with ease. However, the effect of dirty air has improved, and we are seeing more competition between drivers as they can follow each other without losing as much downforce.