From Thursday to Friday, Scuderia Ferrari worked hard to try to solve the porpoising problem, that is to say the bouncing effect of the single-seaters that originates in a straight line as the speed increases. The problem appeared on the F1-75 car on Thursday morning as the drivers accelerated their pace, but it gradually improved with the changes to the floor and set-up, but to be resolved definitively it is necessary to review the floor.
The phenomenon has affected more or less all the teams and it is up to the technicians to find the best solution for the season that is about to begin. Yesterday Mattia Binotto, the Ferrari team principal, said that the issue had been underestimated.
The images of Charles Leclerc literally “bouncing” on the track with the F1-75 have been seen around the world, but in Maranello they have already taken the necessary countermeasures to fix what is an aerodynamic problem that cannot be solved in the wind tunnel.
The bouncing of ground-effect cars is a legacy of the 80s that recurs now, after the 50 mm floor has been removed from the Formula 1 cars and the cars return to touching the asphalt looking for the minimum height from the ground to generate the maximum aerodynamic load in the Venturi channels.
Jean Claude Migeot, aerodynamicist of Renault, Tyrrell and Ferrari, lived through the roaring era of wing cars, and remembers porpoising very well: “The problem is aerodynamic in nature – explains the French aerodynamicist – because it is generated by the elastic characteristics of the flow that influence the effectiveness of the suspension. There is no need to act on the suspension set-up, because the stationary forces increase to the square of the speed and the vertical thrust is much higher than the spring recall capacity. Suspensions cannot be stiffened because they are already very hard, so you have to act on the aerodynamics of the floor”.
Why did the problem only arise on the second day of testing? The answer is quite simple: aerodynamic research is bound by very strict rules that limit work in the wind tunnel. The air blow can be a maximum of 50 m / s, ie a speed of 180 km / h.
This is too low a value to trigger porpoising in the wind tunnel so the phenomenon has not fully manifested itself. The solution, therefore, passes from simulation work to CFD: with the data collected on the track, the teams have the opportunity to understand how to reduce the bouncing.
The teams tried to intervene in two ways: by lifting the car from the asphalt (there are cars that travel 30 mm above the expected value) or by “unloading” the floor with openings.
In the first case the loss of load becomes too important and has a strong impact on performance, while in the second a little aerodynamic efficiency is lost, but the impact on the lap time becomes less devastating.
It is not surprising, therefore, that the “clean” floors that arrived in Barcelona were opened by cracks, cuts and hollows to try to limit the bouncing.
Since this morning, Ferrari has fitted a newly designed floor which has been revised in front of the rear wheel: it shows a round opening under which a curved flap has appeared and the shapes of the trailing edge have changed in front and behind the opening. .
The Maranello technicians have also arranged for the positioning of “sights” to measure with a camera which only the bending of the floor that can contribute to triggering porpoising. These are not changes that were made at the racetrack, but there was the introduction of a new solution which, perhaps, anticipates the concepts that should have been seen in the tests in Bahrain.
Mercedes, for example, limited itself to mounting two tie rods on the W13: the first to fix the floor in front of the rear wheel and the second to prevent the extractor from bending. The bouncing issue was tackled head-on and for this reason in Sakhir we will see the cars change significantly with possible solutions.