At the Austrian Grand Prix, drivers raised concerns about inhaling carbon dust from the brakes and the health consequences. After stepping out of his Aston Martin with a blackened face, Sebastian Vettel explained that this long-standing problem has been made worse this season by the new shape of the air scoops: in addition to being exposed to brake dust emitted by the car generated to follow, drivers now suffer from that of their own car.
If the brake vanes were modified this season, this is to ensure that teams can no longer “outwash” (the path of airflow over and around the front wheels) as easily, specifically by directing air through the wheels . The introduction of a mandatory rear-facing vane outlet was therefore intended to maintain centralized airflow. However, this decision also had consequences for the way pulverized coal is discharged.
Previously, crews vented air, heat and brake dust through the face of the wheel. Aerodynamic advantages could be gained from this, which led to complex designs for brake lines and solutions such as the blown axle and special rims.
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One only has to go back to last year to see how complex the shape of the brake vanes was under the old regulations. The different solutions used by Red Bull on its RB16B show how the ducts have been used to reduce heat transfer from the brakes to the rim and therefore to the tires, better managing the air flow rejected by the wheel’s face. wheel by bypassing the brakes.
Photo by: Giorgio Piola
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For comparison, here are Ferrari’s solutions to exploit different track characteristics and improve the temperature relationship between brakes and tires while controlling airflow.
Photo by: Giorgio Piola
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Before blown axles were banned in 2019, teams used them to bypass the brakes, collecting airflow from the blade to improve airflow around the rim.
Photo by: Giorgio Piola
The new regulations were designed to maintain their intent to reduce the brake vane’s role in generating washout. Standard rims and wheel flanges are part of the equation, and the outer drum creates a seal so airflow can only enter or exit through the front and rear air scoops.
Teams still have some freedom to creatively interpret heat and airflow management in the drum. Many opt for a fairing that surrounds the brake disc, as shown below on the Red Bull RB18.
Close-up of the Red Bull RB18 front brake
The shape, size and position of the inlet and outlet scoops are specified by the regulations, but the designers still have some leeway. However, the FIA can limit these freedoms somewhat by leaning into the rear scoop to alter the passage of brake dust.
It should also be remembered that the diameter of the brake discs has increased significantly this season, from a maximum of 278mm to a fixed limit of between 325mm and 330mm, which theoretically means there is more dust to be blown away.
In addition, the diameter of the cooling holes going through the brake disc must now be at least 3mm, with important consequences for the number and shape of these holes. The regulations also state that no cooling holes are allowed in the brake pads. The combination of these factors means that the amount of brake dust can increase.
Therefore, in consultation with the teams, the shape of the brake discs and air scoops is studied to find a workable solution without eliminating the cause of why the air no longer exits the sides of the car. In the longer term, it’s not out of the question that the FIA could consider something more radical, such as changing the material used for the discs.
The new dimensions of brake discs
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