Modern Formula 1 cars are all about aerodynamics and teams spend hundreds of millions trying to find those last few tenths of a second improving their aerodynamic efficiency.
Aerodynamic engineers have two primary goals. First, they have to create downforce, force generated by car’s wings and underbody which forces car to the ground improving handling, braking and acceleration. Also, they want to reduce aerodynamic drag, force which slows the car down and which increases with downforce. Car which produces same downforce with less drag (or more downforce with same drag) is more aerodynamically efficient.
Several teams in the late sixties began to experiment with wings attached to their cars. Wings on racing cars operate on the same principle as aircraft wings, but resultant force has opposite orientation. The airflow is traveling at different speeds on different sides of the wings (as it must pass a different distance along the contour wings at the same time), resulting in a difference in pressure, which describes physical law known as Bernoulli’s law.
As the pressures tend to equalize, the wing is trying to move in the direction of lower pressure. Aircraft use the wings to create lift and racing cars to create downforce (negative lift).
Modern Formula 1 car can generate lateral cornering acceleration greater than 5g (acceleration 5 times greater than acceleration of gravity which equates 9.81 m/s2).
Downforce generating wings had their F1 debut at Belgian GP 1968. which is historically important for several reasons.
European designers, especially Colin Chapman and Mauro Forghieri, found inspiration in sports cars of American Jim Hall, Chaparral 2E and 2F, which had a large and high-mounted wing. New Zealander Chris Amon qualified on pole in his Ferrari 312 with rear wing with an advantage 3.7 seconds ahead of Stewart in Matra MS10 which showed huge potential of aerodynamic development on racing cars.
On sunday, Bruce McLaren won his fourth and final F1 race in McLaren M7A which was first of many F1 victories for McLaren F1 team.
Golden era and ‘ground effect’
In the mid 70’s Lotus engineers led by legendary Colin Chapman discovered ‘ground effect’, aerodynamic principle using ground as interactive aerodynamic element. The whole car can work as one big wing interacting with moving ground which enabled teams to create enonormous amounts of downforce.
First driver to win the title with a ground effect car was Mario Andretti in Lotus 79 (1978.) with six wins and seven podium finishes, but Ferrari foght back in 1979. with Jody Scheckter winning the title in 312T4, last drivers’ title for Ferrari until 2000.
Probably the most extreme interpretation of ground effect aero is Brahham BT46B designed by legendary Gordon Murray – car used huge fan at the back of the car to suck the air underneath the car, lowering pressure under the car and increasing downforce. Niki Lauda won the race with 34 second advantage over Riccardo Patrese, but after many complaints from other teams its fan was banned immediately.
Ground effect era came to an end prior to 1983. F1 season when FIA banned skirts and heavily limited ground effect due to safety reasons.
Art of aero setup and balance
Every track has its own demands and optimal levels of downforce to be used for best possible laptimes.
If the track has many corners like Monaco or Hungaroring, teams will use all avalaible downforce for better braking, acceleration and cornering performance and they won’t bother for drag penalty too much because of short straights and andvantage they gain in corners.
On some other circuits like Montreal and Monza teams will use low downforce aerodynamic package (shorter wings with less angle of attack) because they generate less drag and allow cars to go faster on long straights, offsetting lost time in corners.
But teams won’t just choose ideal downforce settings for particular track – they have to think about the race too because too much downforce means less competitive straight line speed which can make overtaking and defending very difficult.
Aero driven formula
Aerodynamics of Formula 1 car is probably the most important area of development and variable that separates good cars from winning cars.
Influence of aerodynamics on lap times is so important that it dictates the shape and positioning of many other systems and components of the car.
Every element of Formula 1 car has aerodynamic shape, like drivers’ helmet, suspension elements and rear view mirrors and ultimate goal is to improve aerodynamic efficiency. Some surfaces just need to create as little drag as possible, some have to shape and turn the airflow in desired direction, some create vortices which help energize the airflow, some create downforce. But most of them combine some of those effects to make the car faster and more efficient.
Formula 1 cars have three to four times greater drag coefficient than typical road cars, mostly because of turbulence caused by rotating open wheels, but also because of large openings for radiators and various cooling systems for energy recovery systems, gearbox, hydraulics, brakes etc.
Engineers want their cooling ducts and vents to be as small as possible to cut drag and enable airflow to create more downforce on the rest of the car.
2017. – The beginning of a new era
The change of technical regulations for 2017. is probably the biggest in the last two decades and includes a much wider tires and more freedom in chassis design and aerodynamic package.
Front tyres will be 305 mm wide (currently 245 mm) and rear tires will be 405 mm wide (currently 325 mm). The overall width of the car will be 2000 mm instead of the 1800 mm, and the area where the team may add various aerodynamic elements such as barge boards will be increased (greater freedom for aero designers who will be able to separate turbulent airflow from rotating front wheels more efficiently).
The front wing will be 1800 mm wide instead of 1650 mm and rear 950 mm instead of 750 mm. The rear wing will be 150 mm lower 150 mm (800 mm above the reference plane instead of the previous 950 mm).
To further increase the aerodynamic pressure, diffuser dimensions are also increased – in 2017. it will be 175 mm high (before 125 mm), 1050 mm wide (before 1000 mm), and starts 175 mm in front of the rear axle (before it started exactly at the rear axle). Increased diffuser dimensions increase its volume and therefore the amount of downforce it produces.
In order to compensate for the additional weight from bigger tyres, the minimum weight will be increased from 702 to 724 kg.