(Photo by Abed Ismail/Unsplash)
Ask any race car engineer and he’ll tell you that the most important part of race car design is aerodynamics. In fact, it may well be the difference between the development of a championship-calibre machine and ending up with one that is always bringing up the rear.
Simply put, aerodynamic design is concerned with two primary disciplines - the creation of lines that facilitate down-force, which causes the tires to hug the track more vigorously, and the reduction of drag, the effect air has on a car’s surface that works to slow down the machine.
Although it has always been an important factor in race car design, attention to aerodynamics increased dramatically in the 1960s when some racing teams began experimenting with the wings that are so familiar today. Wings on race cars, or airfoils, work using the same principle as aircraft wings, only instead of lifting the vehicle off the ground, they force it to cling to the roadway.
When air flows over the wing’s two surfaces, it does so at different speeds, as a result of the slight distances the contours force the air to travel. This creates a difference in the air pressure, a rule in physics known as the Bernoulli Principle. When the air pressure attempts to equalize, the wing is forced into the direction where the air pressure exerts the least amount of force.
Aircraft also use this principle to create lift, while race cars use it to create downward force. Modern formula 1 race cars are capable of producing G-forces of lateral force (the equivalent of 3.5 the car’s own weight) during cornering, thanks to the aerodynamics built into the design. This means that the vehicle could drive upside down, theoretically speaking, of course.
Early on, experiments with airfoils and their increasing heights and designs resulted in some spectacular accidents, forcing the governing bodies to introduce regulations limiting the size and position of airfoils. And although they have continued to be modified over the years, those regulations are still in place today.
In the mid-70s, however, the discovery of ground-effect down-force eliminated the need for those huge airfoils prevalent on the rear of Formula 1 race cars. Engineers at Lotus came up with an ingenious new design for the underside of the vehicle that transformed the entire undercarriage of the car into one giant airfoil, so to speak, that acted to pull the race car down toward the track.
The personification of this type of ingenuity came in the form of the Brabham BT46B - designed by Gordon Murray - which used a fan to pull in air from an airtight duct under the race car, creating an enormous amount of down-force. When several of the other racing teams mounted technical challenges, however, the modification was removed, after having completed only one race. Later rule changes also limited the use of ground effects which gave unfair advantages to some drivers. The first modification to go were the skirts that covered the low-pressure area, then the stepped floor requirement.
In the years that followed, aerodynamic development has been more coordinated, however, the exponential increase in speed via other means has forced regulators to modify and tighten some restrictions when the need arose.
Consequently, today’s aerodynamic engineers have a lot less freedom than their counterparts from the old days. With the introduction of stricter rules governing everything from the height and width of airfoils to location and bodywork. Nevertheless, with each additional ounce of down-force translating into more milli-seconds of time saved per lap, racing teams continue to invest heavily in things like wind tunnel research and computational fluid dynamics (CFD) - the leading areas of aerodynamic research, as they continue to try to squeeze every ounce of speed out of their vehicles as they can.
For Formula 1 race cars, the most visible aerodynamic devices are the wings located on the front and rear of the vehicle. Working in conjunction, these devices account for 60 percent of the down-force exacted on the vehicle. The wings can be outfitted with different profiles, depending on the down-force requirements of each track. Tracks with slow, tight circuits like those found in Monaco demand wing profiles that are very pronounced to maximize the amount of down-force created, while faster tracks, like Monza, the size of the wings are greatly reduced to limit the amount of drag while increasing speed on those long straightaways.
Every surface area involved in a Formula 1 race car, from the suspension to the driver’s helmet, must figure into the design consideration. The reason being that, when the airflow is disrupted, it creates turbulence, which in turn creates drag, which acts to slow the vehicle.
In fact, when you consider modern Formula 1 race car closely, you’ll find that as much attention has been given to reducing drag and managing air-flow as there has been to producing more down-force. From the vertical endplates attached to the airfoils, to prevent the formation of vortices, to the diffuser mounted on the rear of the vehicle, a modification that helps equalize air pressure from fast-moving air flowing under the car that could produce a low-pressure balloon, creating drag at the rear of the vehicle. Nevertheless, drivers don’t want to make their cars so aerodynamic that it inhibits the car’s ability to cool critical parts and the power train.
Ingenious Formula 1 engineers will always find a way to pole holes in the regulations and introduce yet another clever aerodynamic breakthrough. And just as with what happened with the introduction of diffusers, F-ducts, and exhaust-blown diffusers, they too will be summarily banned by the regulators. However, there is one innovation that has been warmly received by the regulators and that is the DRS (Drag Reduction System). It was introduced to promote more overtaking by allowing drivers to adjust the angle of the rear wing’s main plane to reduce drag and increase speed on the long straightaways. However, there is a drawback, and that is, it can only be used on certain parts of the track where the driver is within a second of the car in front of him.