What is the fluorescent paint used on F1 cars during testing?

F1 cars often have bright colored paint smeared across their liveries during a test. The unique paint is called ’Flow-vis', a short form of Flow Visualization paint that is used to determine the aerodynamic performance of the car. With new aerodynamic regulations for the 2022 season, several teams were seen with bright paint smeared on their cars during the preseason test in Barcelona.

Flow-vis paint is a powdered paint or fluorescent powder usually mixed with paraffin oil. The paint is applied or sprayed on the car to determine the airflow structure. Some teams use fluorescent paint, which can only be viewed under UV light.

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What happens when Flow-vis paint is applied to an F1 car?

When the F1 car picks up speed, the oil dries up and the paint reflects fine detailed patterns across the car made by the airflow, which are rarely visible to the naked eye. Flow-vis paint is used when teams want to test a particular aerodynamics concept or part and understand if it is working correctly or to understand the direction of the airflow of the complex F1 car.

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Why is a Flow-vis test done on an F1 car?

When the car returns to the garage, the patterns will be photographed for analysis by the engineers. A Flow-vis test is performed to confirm the data gathered from Computational Fluid Dynamics (CFD) or the wind tunnel. Aerodynamicists and engineers used data gathered from visual references or detailed patterns of paint to check the performance of components such as wings, winglets, air-vents, or any new aerodynamical component in a car. The data is not absolute evidence that it can be relied upon, but a confirmation to determine the functioning of the aero components on the car or confirm the structured airflow required to confirm the functioning of the component.

In an experimental environment such as an F1 test, where teams test various parts of their cars, flow-vis paint is a common sight. Teams often use it as evidence that they can hide from other teams, since the detailed patterns on the car surface cannot be viewed by the naked eye but only by a High Definition camera.

Therefore, this method is often used as a last resort or a quick reference to understand what the airflow is doing around the car. Once the evidence is collected, it is immediately wiped off by the team personnel. Since the composure is that of paraffin oil and powdered paint, the paint can be easily wiped off without leaving evidence for a rival team to notice.