Aerodynamics
Wings
Early designs linked wings directly to the suspension, but several accidents led to rules stating that wings must be fixed rigidly to the chassis. The cars' aerodynamics are designed to provide maximum downforce with a minimum of drag; every part of the bodywork is designed with this aim in mind. Like most open wheeler cars they feature large front and rear aerofoils, but they are far more developed than American open wheel racers, which depend more on suspension tuning; for instance, the nose is raised above the centre of the front aerofoil, allowing its entire width to provide downforce. The front and rear wings are highly sculpted and extremely fine 'tuned', along with the rest of the body such as the turning vanes beneath the nose, bargeboards, sidepods, underbody, and the rear diffuser. They also feature aerodynamic appendages that direct the airflow. Such an extreme level of aerodynamic development means that an F1 car produces much more downforce than any other open-wheel formula; for example the Indycars produce downforce equal to their weight at 190 km/h (118 mph), while an F1 car achieves the same downforce:weight ratio of 1:1 at 125 km/h (78 mph) to 130 km/h (81 mph), and at 190 km/h (118 mph) the ratio is roughly 2:1.[4]
The 'barge boards' in particular are designed, shaped, configured, adjusted and positioned not to create downforce directly, as with a conventional wing or underbody venturi, but to create vortices from the air spillage at their edges. The use of vortices is a significant feature of the latest breeds of F1 cars. Since a vortex is a rotating fluid that creates a low pressure zone at its centre, creating vortices lowers the overall local pressure of the air. Since low pressure is what is desired under the car, as it allows normal atmospheric pressure to press the car down from the top, by creating vortices downforce can be augmented while still staying within the rules prohibiting ground effects.[dubious – discuss]
The new F1 cars for the 2009 season have come under much questioning especially the rear diffusers of the searingly fast Brawn GP cars raced by Jenson Button and Rubens Barichello. Appeals from many of the teams will be heard in the early part of the 2009 season.
Ground effects
F1 regulations heavily limit the use of ground effect aerodynamics, which are a highly efficient means of creating downforce with a relatively small drag penalty. The underside of the vehicle, the undertray, must be flat between the axles. A 10mm[5] thick wooden plank or skidblock runs down the middle of the car to prevent the cars from running low enough to contact the track surface; this skidblock is measured before and after a race. Should the plank be less than 9 mm thick after the race, the car is disqualified.
A substantial amount of downforce is provided by using a rear diffuser which rises from the undertray at the rear axle to the actual rear of the bodywork. The limitations on ground effects, limited size of the wings (requiring use at high angles of attack to create sufficient downforce), and vortices created by open wheels lead to a high aerodynamic drag coefficient (about 1 according to Minardi's technical director Gabriele Tredozi[6]; compare with the average modern saloon car (sedan in the USA), which has a Cd value between 0.25-0.35), so that, despite the enormous power output of the engines, the top speed of these cars is less than that of World War II vintage Mercedes-Benz and Auto Union Silver Arrows racers. However, this drag is more than compensated for by the ability to corner at extremely high speed. The aerodynamics are adjusted for each track; with a relatively low drag configuration for tracks where high speed is relatively more important like Autodromo Nazionale Monza, and a high traction configuration for tracks where cornering is more important, like the Circuit de Monaco.
Regulations
The FIA is hoping to rid F1 of small winglets and other parts of the car (minus the front and rear wing) used to manipulate the airflow of the car. This is in order to not only decrease downforce, but also to increase drag. As it is now, the front wing is shaped specifically to push air towards all the winglets and bargeboards so that the airflow is smooth. Should these be removed, various parts of the car will cause great drag when the front wing is unable to shape the air past the body of the car. New regulations coming into effect in 2009 have reduced the width of the rear wing by 25 cm, and standardised the centre section of the front wing to prevent teams developing the front wing.