Perez’s crash helps unravel RB18’s secrets

Sergio Perez won the Monaco Grand Prix, but it cannot be said that the entire race weekend went smoothly for the Mexican as he made a mistake at the end of qualifying, which damaged the car in the Portier corner.

This error can have certain consequences, which is the subject of the text in the German edition of Auto Motor und Sport. When his RB18 was evacuated, the photographers had the opportunity to capture the underside of the car in detail, and there is no doubt that these photos, which immediately spread across the internet, were available to all championship teams.

Since various types of incidents are quite common in Monaco, and in the event of an accident, a car can be evacuated from a narrow city road mainly with the help of a crane (there are 11 of them), in such situations it is most likely to go to certain technical solutions to look.

The underbody of a modern Formula 1 car is a very complex and extremely important element of the aerodynamic body kit. In the new generation of cars, it is the underside that is responsible for 40% of the downforce.

It is created by peculiar tunnels or channels on both sides of the bottom, which start in the front part and go to the side pontoons and the rear of the car. The airflow passing through these channels to the diffuser, which is also involved in all these processes, accelerates and thanks to the so-called “Venturi effect”, an underpressure area is created under the floor, pushing the car against the asphalt.

Specialists in aerodynamics, developing such a bottom, solve various problems. First of all, it is important to ensure that as much air as possible enters this area of ​​the machine. In addition, we must try to make it race through the tunnels in the right direction, and not to the sides, because then the bottom works less efficiently.

The baffles separating these channels have a special shape, including their edges, which create additional aerodynamic vortices.

This year, team engineers have to deal with such an unpleasant phenomenon as the longitudinal build-up of the car at high speeds. According to Adrian Newey, head of the technical department at Red Bull Racing, it occurs precisely in those parts of the ground where maximum downforce is created: the airflow is not stable, and under certain conditions it breaks down, then it recovers, but then weakens again, and all this repeats itself cyclically.

In the middle of the front of the bottom is a small horizontal winglet that affects the airflow, it becomes a little more stable and moves in the right direction. The first such solution was applied in Ferrari and Aston Martin, then it was copied in Red Bull and Mercedes.

But that’s not all: the construction of the car is strongly influenced by parameters such as the stiffness of the bottom and the height of the ride height.

“There are so many factors that can make the swing stronger or weaker,” explains McLaren technical director James Key. – This is the movement in a turbulent flow, and the roughness of the track, and the stiffness of the suspension and tires. The machine is affected by side loads, but chassis settings also affect aerodynamics. Therefore, all this is extremely difficult to model on the simulator.

By the way, in Monaco, after Daniel Riccardo’s accident at the start of the second training session, photographers had a great opportunity to photograph the underside of the McLaren car.

The aforementioned wobble issues had much less impact on Red Bull Racing and rivals wondered what the secret was to the RB18’s stable behavior on the track. But after Saturday Perez’s accident in the Porter turn, at least they have photos and videos worthy of a thorough analysis. And since Carlos Sainz’s car was also evacuated from the Portier corner using a crane, everyone had the same chance to see the underside of the Ferrari.

If desired, these “spy” shots are available for anyone interested in Formula 1 technology. When you look at them, you immediately notice that the underside of the RB18 is much more detailed and has a more complex shape. At Ferrari, for example, all channels are approximately the same width, while at Red Bull their geometric dimensions are different and the outer tunnel is quite narrow. Incidentally, a similar solution can also be seen on an Aston Martin car.

What function all these functions of the underside of the RB18 serve is only known to their authors, but probably rival teams will know it soon. True, it is impossible to directly copy these solutions, because they do not exist and work on their own, but in complex interaction with other elements of the aerodynamic body kit – with the front wing and other components on the front of the car and on a form the airflow in a special way, part of which goes to the bottom.

Limited budgets are also a serious obstacle to major changes to the cars this year, so some key decisions that affect the efficiency of the entire chassis can only be implemented in the developments we will see next season.