Aerodynamics

Ask any engineer in the pit lane and they’ll tell you that the most important consideration in F1 car design - the difference between designing a championship-challenging machine or a tail ender - is aerodynamics.

In simple terms, F1 aerodynamicists have two primary concerns: the creation of downforce, to help push the car's tyres onto the track and improve cornering forces; and the minimisation of drag, a product of air resistance which acts to slow the car down.

Although always important in race car design, aerodynamics became a truly serious proposition in the late 1960s when several teams started to experiment with the now familiar wings. Race car wings - or aerofoils as they are sometimes known - operate on exactly the same principle as aircraft wings, only in reverse. Air flows at different speeds over the two sides of the wing (by having to travel different distances over its contours) and this creates a difference in pressure, a physical rule known as Bernoulli's Principle. As this pressure tries to balance, the wing tries to move in the direction of the low pressure. Planes use their wings to create lift, race cars use theirs to create negative lift, better known as downforce. A modern Formula One car is capable of developing 3.5 g lateral cornering force (three and a half times its own weight) thanks to aerodynamic downforce. That means that, theoretically, at high speeds they could drive upside down.

Early experiments with movable wings and high mountings led to some spectacular accidents, and for the 1970 season regulations were introduced to limit the size and location of wings. Evolved over time, those rules still hold largely true today. 

By the mid-1970s 'ground effect' downforce had been discovered. Lotus engineers found out that by cleverly designing the underside of the car, the entire chassis could be made to act like one giant wing which sucked the car to the road. The ultimate example of this thinking was the Brabham BT46B, designed by Gordon Murray, which actually used a cooling fan to extract air from a sealed area under the car, creating enormous downforce. After technical challenges from other teams it was withdrawn after a single race. Soon after rule changes followed to limit the benefits of 'ground effects' - firstly a ban on the skirts used to contain the low pressure area, then later a requirement for a 'stepped floor'.

In the years that have followed aerodynamic development has been more linear, though ever increasing speeds and various other factors have led the sport’s regulators to tweak and tighten the regulations on several occasions. 

As a result, today’s aerodynamicists have considerably less freedom than their counterparts from the past, with strict rules dictating the height, width and location of bodywork. However, with every additional kilogram of downforce equating to several milliseconds of lap time saved, the teams still invest considerable amounts of time and money into wind tunnel programmes and computational fluid dynamics (CFD) – the two main forms of aerodynamic research. 

The most obvious aerodynamic devices on a Formula One car are the front and rear wings, which together account for around 60 percent of overall downforce (with the floor responsible for the majority of the rest). These wings are fitted with different profiles depending on the downforce requirements of a particular track. Tight, slow circuits like Monaco require very aggressive wing profiles to maximise downforce, whilst at high-speed circuits like Monza the amount of wing is minimised to reduce drag and increase speed on the long straights. 

Every single surface of a modern Formula One car, from the shape of the suspension links to that of the driver's helmet - has its aerodynamic effects considered. This is because disrupted air, where the flow 'separates' from the body, creates turbulence which in turn creates drag and slows the car down. In fact, if you look closely at a modern car you will see that almost as much effort has been spent reducing drag and managing airflow as increasing downforce - from the vertical endplates fitted to wings to prevent vortices forming to the diffuser mounted low at the rear, which helps to re-equalise pressure of the faster-flowing air that has passed under the car and would otherwise create a low-pressure 'balloon' dragging at the back. But despite this, designers can't make their cars too 'slippery', as a good supply of airflow has to be ensured to help cool the various parts of the power unit.

The ingenuity of F1 engineers means that every now and then a loophole will be found in the regulations and a clever aerodynamic solution will be introduced. More often than not these devices, such as double diffusers, F-ducts and exhaust-blown diffusers, will be swiftly banned, but one innovation that has been actively endorsed is the DRS (Drag Reduction System) rear wing. This device, which was introduced to encourage more overtaking, allows drivers to adjust the angle of the main plane of the rear wing to reduce drag and increase straight-line speed, though it may only be used on specific parts of the track and when a driver is within one second of the car ahead in a race.