An air of calm - Toyotas Mark Gillan on aerodynamics 31 Oct 2007
Japanese team's head of aerodynamics on how to harness airflow
Aerodynamics in Formula One racing is often described as a black art, the real secret to success on the track. But as Toyotas head of aerodynamics Mark Gillan explains, the answer is blowing in the wind.
First and foremost, aerodynamics is the science of manipulating and making use of airflow. In Formula One racing, high speeds mean the air is a formidable force and it can be used to the cars advantage, as well as presenting an obstacle to speed.
Put simply, the bigger the frontal area of an object, the more wind resistance it will encounter, so a bigger object will travel slower than a smaller object with the same amount of power to propel it.
As always in Formula One racing, things are not that simple. Downforce complicates matters, because wind resistance can be used to improve a cars performance, if the forces are transferred in the right way to provide extra grip around corners.
Gillan explains: Downforce is simply the force acting down on the ground. If you think of an aircraft, it has lift - a force acting upwards. On our car we have wings which work in the opposite direction to those on an aeroplane. On our car we have a force which acts down on the ground to keep the car fixed to the track as it is going around corners.
Maximising the positive effects of the air and minimising the negative effects is the aerodynamicists challenge. The first attempts to harness aerodynamics in Formula One racing were relatively crude and dangerous, but the technology and knowledge has evolved into a fine art, which literally dictates who succeeds and who doesnt.
Aerodynamics in Formula One has been around a long time, Gillan says. Way back in the late 1960s the first aerodynamic wings were sprouted and then, in the 1970s, understanding of aerodynamics on racing cars became more apparent. But its really in the last 10 years that Formula One aerodynamics has progressed beyond all recognition. It is really very impressive.
Aerodynamics is now the most important item on the car which a team can actually change, because if you look at the tyres, everyone has the same tyres and the engine is homologated. So aerodynamics is the single biggest item we can change - the biggest performance item on the car.
Although every part on the outside of Toyotas TF107 car is designed with aerodynamics in mind, the most obvious aerodynamic elements are at the very front and rear of the car.
As the first part of the car to encounter air resistance, the front wing is a key to the aerodynamic puzzle. It channels the air around and over the car, ensuring it reaches the right areas to generate downforce, but avoids places where it has a negative effect.
Gillan explains: The front wing is one of the more efficient areas on the car. It basically provides the downforce at the front of the car, to provide stability and increase grip. But it is also a mechanism for directing the air away from the tyres. The tyres are one of the main items which generate drag. From a legality point of view, we cannot cover the tyres so we have to find a way to move the air around and over them.
To get the perfect set-up, we typically start at the front and work our way back because each item at the front, for example the front suspension, will have a knock on effect on the rest of the car.
But that does not diminish the importance of aerodynamics at the other end of the TF107, as Gillan adds: The rear wing, like the front, generates downforce. It is the balance between downforce at the front and the downforce at the rear which provides stability.
Because Formula One cars are incredibly sensitive to small changes in set-up, the TF107s are built to allow fine-tuning to maximise the useful effect of the wings. If you look at the rear wing, you can see various hole positions, Gillan says. What we can do is change the angle of the wing elements which generates less or more downforce as required.
Of course, with aerodynamics being such a pivotal factor in determining performance on the track, Toyota leave no stone unturned as they search for the small improvements which combine to deliver success.
At their headquarters in Cologne, Germany, the team use the latest technology to put designs to the test before they even make it on to a race track with a two-pronged approach. Powerful computers are able to simulate the effect of airflow over the car without it even needing to be built, while in the wind tunnel, an exact scale model of the TF107 is subjected to a wind flow which replicates driving at speed.
We spend roughly 8,000-9,000 hours a year just to develop the car in the wind tunnel, says Gillan. That is in addition to a similar amount of time in CFD, computational fluid dynamics, which is a computer programme which models the air flow over the car.
The comprehensive data from these tests shows the team how the car behaves at racing speed, giving Gillan and his colleagues the information they need to constantly improve the aerodynamics.
Constant improvement - kaizen in Japanese - is a fundamental philosophy of Toyota and aerodynamics play a pivotal part in their challenge to reach the front in Formula One racing.