Formula 1 cars are intricately designed to carefully direct airflow onto specific parts of the car. While teams can simulate this with wind tunnels and computer models, there’s nothing as accurate as the real thing. But what can help on the track is something called flow-vis/flow-viz paint.
Flow-vis paint in F1 is a wet, normally green liquid sprayed onto the car that dries as the car gets up to speed. Once the paint has dried, teams have an accurate representation of how the air flows over the car by the way the paint has been pushed around by the air and dried in place.
Flow-vis paint might seem like a strange concept, but it’s very important for the engineers who need to analyze how to improve the car. F1 cars often have flow-vis paint on them during preseason testing or free practice. Below, we’ll go over everything you need to know about flow-vis paint in F1.
What Is The Green Paint They Spray On F1 Cars?
The green paint on F1 cars is a fast-drying paint known as flow-vis. It’s made from a fluorescent powder mixed with a light oil and is then applied to the car. As the car drives around the circuit, the oil evaporates from the mixture, allowing the paint to dry as it’s moved around by airflow.
During preseason testing and practice sessions, many teams will send their cars out on track with the bright green liquid on various parts. The car will do a few laps and then return to the pits where engineers will carefully study the liquid and take photographs of it.
While the paint is still wet, the air pushes it around the car. This allows the paint to give a visual indication of where the air flows around the car and how the air interacts with the various parts of the body of the car. This lets teams understand how well their wind tunnel tests and computer simulations correlate to what actually happens when the car is out on track.
Aerodynamics is extremely important in Formula 1, and understanding how the air interacts with the car is one of the most important elements in designing the car. Teams can use this information to plan their future aerodynamic upgrades, and tweak setup changes where necessary, to get the most out of the car.
Why Do Some Teams Use Different Colors Of Flow-Viz Paint?
While bright green is the most common color when it comes to flow-vis paint, it’s not the only color that is used by the teams. Many teams use different colors of flow-vis paint on their cars, and this is simply to make it more visible, or to help distinguish multiple sections of airflow if they’re using it on multiple parts of the car at one time.
Some cars have liveries where the green flow-vis might be difficult to see, especially when you consider that teams need to carefully trace how the air flows over the body of the car. For example, Aston Martin already use green cars, which may make the paint difficult to see when over some parts of the car.
How Does Flow-Vis Paint Work In F1?
Flow-vis paint is made by the F1 teams. It’s a mixture of powdered paint and oil. Once the mixture is made, it’s sprayed over the car. The paint will run over the car during a lap and expose the car’s aerodynamics, by showing visually where the airflow has moved the paint over the car.
With the car covered in flow-vis paint, it needs to get out on track as quickly as possible. This is because the paint dries as the oil evaporates from the mixture, which tends to happen quickly when heat and wind are at play, and of course at the high speeds F1 cars drive, the airflow over the car is very fast, which dries the paint very quickly.
This means that the flow-vis paint is usually painted onto the car at the very last minute before it leaves the garage. As the car drives around the track, the paint is pushed around the car by the moving air. The paint then dries and gives the team a clear indication of how their aerodynamics disrupt and manipulate the air around the car.
Why Is Flow-Vis Paint Important?
Aerodynamics is one of the most important elements of Formula 1. The way the cars’ wings and bodywork interact with the air flowing over it will influence the amount of downforce the car gets through the corners, as well as the drag that slows the car down on the straights.
With on-track testing being extremely limited in Formula 1, teams need to rely on simulations and scale model testing in wind tunnels to see how their car’s aerodynamics work. When the teams get a chance, such as during preseason testing or during free practice, they test out their aerodynamics on-track using flow-vis paint.
This allows teams to visually see the air moving over the car and where it’s being directed. Teams may also test new parts to see whether they are working as intended and whether the air is being directed where they want it to go.
Is Flow-Vis Accurate?
Over years of testing and development, teams have been able to build relatively accurate models and simulations of their cars in their factories. Teams can simulate the airflow over the car on a computer screen to see how effective their aerodynamics will be. Teams also build scale models of their cars and use a wind tunnel to simulate airflow over the car.
These two elements can be very accurate in terms of how the car interacts with the air flowing over it, but there’s nothing as accurate as the real thing. With limited time with a real car on a real track before the races, teams make use of flow-vis to see if their simulations have been accurate and if their aero parts are doing their jobs correctly.
Flow-vis does have its limitations, and the paint may move or dry faster than the teams would like. For example, they may want to see how the air flows over their car at a specific part of the track, but by the time the car reaches it, the paint may have dried in already. This means flow-viz paint is a fairly rudimentary way to see how the air flows over an F1 car.
When Did Formula 1 Teams Start Using Flow-Vis Paint?
F1 teams first started using flow-vis paint in 2010, and McLaren was the first team to begin using it on their car. However, when something works, others take notice, and the rest of the F1 paddock quickly jumped on board and used flow-vis on their own cars.
Ever since flow-vis was introduced, the aerodynamic parts on the cars have developed massively. Flow-vis has become a staple for Formula 1 teams ever since, and every team now uses the paint during testing and practice sessions.
Why Is Flow-Vis Paint Fluorescent?
Flow-vis paint is fluorescent as brighter colors are much easier to distinguish from the rest of the car. The fluorescent colors stand out against the cars’ liveries, which makes it clearer to the teams’ engineers how the air is flowing over the car.
The paint can’t go all over the car, as the engineers need to carefully trace where it goes. Some of the paint will begin to trail off and become thinner, but having fluorescent colors will help the teams to keep track of the paint trails even when they begin to thin out.
Why Do Some Teams Use Paint That’s Difficult To See?
Not all teams use brightly colored fluorescent paint on their cars, especially not when testing out new aerodynamic parts and upgrades. Many teams use a type of flow-vis paint that is invisible to the naked eye so other teams can’t see what they are up to.
Teams use this paint when they test upgraded aero parts that could be copied by other teams. The problem is that the brightly colored fluorescent paint can be seen by other teams and engineers, especially when the cars are photographed by the media.
Teams may therefore use flow-vis paint that doesn’t show up on the car very well and can only be properly seen under ultraviolet light back in the garage. This allows the teams to keep their data and airflow visualization to themselves as much as possible, rather than allowing all the other teams to see it as well.
Final Thoughts
Flow-vis paint is sprayed onto F1 cars during testing or practice sessions. This allows F1 teams to see how the air flows around the body of the car. This helps teams develop their cars and understand how well their wind tunnels and computer simulations correlate to on-track performance.
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