History background: Aerodynamics in F1
Aerodynamics: Lesson 11
Aerodynamics in Formula 1.
In Formula 1, the main objective is to make the car as fast as possible without losing control due to the excessive engine power and poor grip on the ground. Beyond the technical-mechanical development, to improve performance it is necessary to decrease the resistance with the air flow, known in the automotive field as “drag”. In next lines, we’ll review the evolution of aerodynamics in F1, do you remind all of them?
Therefore, it is therefore clear how, from the beginning, the aerodynamic studies have been a fundamental element of the design of racing cars to increase its performance. And since the 1960s, in fact, technicians and engineers had understood that by increasing the downward pressure (downforce) it was possible to increase the grip between the wheels and the road, or the handling necessary to be able to transfer the power generated by the engine on the track. With a good amount of downforce, it is possible to limit the sliding of the wheels and make the car more stable even after a sudden change of direction. The action of wings, flow diverters and other components of the chassis became relevant in this.
From the beginning, the uncovered wheels of the F1 cars represent a significant aerodynamic brake. Despite the technological limitations of the time, the problem of finding a shape for racing cars, that would guarantee the best penetration into the air, arises. The first designers did not have to try very hard to identify this shape, since it was already present in nature: the drop.
Starting from the legendary Auto Union of ’37 (photo on the left), which is the forerunner, they study more tapered shapes, with cambering behind the driver or on the sides (see Manuel Fangio’s Ferrari D50, right), in order to make the movement of the air around the car body as linear as possible and thus limit turbulence.
The extreme search for maximum aerodynamic penetration leads to the design of increasingly long (also due to the rear engine) and thin (in the image, Jim Clark’s Lotus 33) cars, with the rider’s position increasingly relaxed, enough to make their “cigar” shape famous.
But in ’67 wing appendages appeared on many cars – which would have distorted the shape of the cars in the years to come – whose function is to significantly increase the travel speed of the curves. These wings become “adjustable“, that is, regulated directly by the racing driver, to overcome the handicap of the remarkable air resistance mainly in the fast straights. However, the low level of technology of the time and also the impossibility of avoiding failures to such a delicate mechanism cause numerous tragic events that induce sports power to set limits for the first time on the aerodynamics of cars and to impose the use of fixed wings.
They represent the most fertile and generous decade of ideas for F1, at least in the field of aerodynamic innovations of cars, with the introduction and affirmation of new concepts at the base of the design of the chassis and appendices, radically changing the appearance of the single-seaters which now appear wider and flattened on the ground. It is the period in which even small teams can achieve excellent results simply by exploiting the ingenuity and intuition of their engineers.
Just in these years Colin Chapman’s Lotus also introduces the so-called “ground effect“, gradually abandoning the “old” wing fin.
The downward load generated by the inverted wing sides combined with the side-skirts, a sort of strips that sealed the bottom of the cars, in addition to the introduction of the powerful turbo engines, make Formula 1 vehicles difficult and dangerous for drivers to manage. In curves, lateral acceleration levels are reached by an airplane pilot, subjecting the body to a great effort. The driving style is also very affected, because of the suspension that must be rigid to keep the car parallel to the asphalt and make it run as on railways, making it almost impossible to change the trajectory when cornering, once set.
The dangerousness of these technical solutions is reflected in dramatic accidents: due to the particular wing shape of the car, the loss of downforce due to the deterioration of the side-skirts or the sudden raising of the nose following a collision at speed, almost always makes it stand out the flight to the car. Precisely for these reasons, in 1983 the International Federation forbade the use of side-skirts and the ground effect on Formula 1 cars.
Following these prohibitions, we see a revival of wing appendages, also very showy, in order to keep the cars, that have become “monsters” of over 1000 horsepower, on the ground. Therefore, the search for the best aerodynamic penetration starts again to encourage the outflow of air in the least turbulent way possible.
It is the Benetton stables that introduce the high nose. While presenting the disadvantage of raising the center of gravity of the car, this new solution allows a greater flow of air into the body bottom, creating a certain ground effect.
The aerodynamic study has moved for some years on details such as the suspension fairings, the flow diverters, the aileron bulkheads, the hot air flows coming out of the exhausts … This has made the use of the “wind tunnels“, huge and very expensive systems that reproduce almost the race conditions. The latest solutions in the field of aerodynamic appendages concern the search for elastic materials, with which to build “variable” wings according to speed. A return to the old, but very close to the limit, to the detriment of security.