Formula 1 faces
a big aerodynamic dilemma and, at every race, a new challenge. The problem
can not be solved by brute force – there is no single set-up which works
perfectly at every track. The true art of modern Formula 1 racing is to come
closer to perfection than the competition can. The shape of the cars is
honed on the computer, in the wind tunnel and on the racetrack; and the
wings and wind deflectors have to conform just as much as the diffuser on
the rear underbody of the car. Everything is done to channel the airflow as
perfectly as possible and to create the maximum amount of downforce.
Nowadays, aerodynamics is a question of attending to the tiniest detail. An
air-duct panel (or barge-board) between the front wheel and the side panel
can add more speed than an engine with two or three extra horsepower. The
aerodynamics are the most important factor in the design of a Formula 1 car.
The path to this discovery is lined with daredevil experiments,
revolutionary inventions and new technological developments. Even so, in the
early years of motor racing, the term ‘aerodynamics’ was rather an
unfamiliar concept; the front of the car was a bluff obstacle and therefore
the cars generated lift rather than
downforce. As a result, many of the early designs were soon ‘gone with the
wind’...
In the beginning – 1968 – it was not possible to precisely calculate the
forces generated by the oncoming airflow, so the teams had to progress by
trial and error; as a result, the front and rear spoilers (or aerofoils),
which were fitted on delicate struts, kept breaking off… Formula 1’s
governing body reacted by stipulating that the spoilers would have to be
fitted directly onto the rear of the car in 1969.
A stroke of genius by the great designer and founder of Lotus, Colin
Chapman, in 1972 showed the way ahead for Formula 1. Chapman designed the
Lotus 72 with a pointed ‘shovel’ nose and a nose-cone in the form of a
wedge, and the radiators were fitted into sidepods. This also had the effect
of moving the car’s centre of gravity toward the rear. Lotus promptly won
both the Drivers’ and the Constructors’ World Championships. Thanks to its
revolutionary aerodynamics, the Lotus drove 15 kph faster on the straights
than its predecessor with the same engine power.
It was Colin Chapman again who introduced another design breakthrough in
1977/78. The Lotus 78 featured inverted wings which generated downforce, so
naturally the car was soon dubbed the ‘Wing Car’. The side-skirts on the
side of the Lotus were virtually flush with the asphalt, this created a
vacuum which pressed the car on to the track and allowed incredibly high
cornering speeds. Success followed quickly: in 1978 the Lotus driver, Mario
Andretti, won the World Championship.
The so-called ‘ground-effect era’ lasted until 1982. Even before the 1981
season, the FIA had banned for safety reasons the use of movable sideskirts
on the underside of Formula 1 cars, in order to increase the ground
clearance and thus reduce the cornering speeds. In 1983, the flat-bottom
regulation came into force, which prohibited all aerodynamic aids that
generated downforce on the underside of the cars. The cars were then given
narrower designs again, so the developers began to turn their attentions to
small aerodynamic details.
In the 1990s, aerodynamics definitively became the central issue in Formula
1 development. The most significant innovations included, for instance, the
front trim of the Tyrrell in 1990; Harvey Postlethwaite succeeded in guiding
the air around the underbody and the radiators far more efficiently. In
1987, Team Lotus introduced active suspension, which guaranteed an
unchanged, ideal flow angle, but it wasn’t until 1991’s Williams FW14 that
active suspension started to make a real impact in F1.
The FIA reacted to the inventive spirit of the engineers with further
restrictions designed to reduce the aerodynamic efficiency and so ensure
lower cornering speeds and greater safety. In 1994, all electronic aids,
including active suspension, were banned following the tragic San Marino
Grand Prix. However, the designers keep on successfully compensating for
these restrictions with new innovations and continued development.
By 1998, there had been experiments with numerous different wing variants:
for instance, Tyrrell used the so-called X-wings (winglets mounted on stilts
on the sidepods) and many teams introduced winglets (small additional wings
fitted to the outsides of the rear wings). At the same time, the FIA made
drastic changes to the regulations (narrower cars, grooved tyres) which
meant that the aerodynamicists had to find new ways to win the battle
against the wind.
Most teams now possess their own wind tunnel, where they usually work
roughly 3600 hours (150 days) per year. In modern wind-tunnels, the airflows
are made visible by laser, because nowadays, it is more important than ever
to give the car a perfect balance with a set-up suited to all the features
of the race track. “The design has to ensure that there is a maximum level
of downforce at all times,” says Max Nightingale, Head of Vehicle Dynamics
at Williams. “A sort of dynamic downforce is important to keep the car
balanced all the time – on fast straights, or in fast or slow corners.”
As the 2003 season begins, the occasional unconventional wing has been
sighted on the test tracks. However, given the current state of technology,
it is unlikely that there will be any revolutionary new developments like in
the 1960s and 1970s. The dilemma still exists; the aerodynamicists are now
relying on steady evolution rather than revolution because they know that in
Formula 1, finding just an extra hundredth of a second or two per lap might
be enough to win.
In contrast to Formula 1, there is no need to make production passenger cars
a fraction of a second faster, but the air resistance is still a primary
concern for passenger car aerodynamicists. It is a fact that a car’s driving
performance depends on its aerodynamic performance; it influences fuel
consumption, top speed and, to a lesser extent, acceleration. All of these
are decisive features when buying a car. Passenger cars can certainly learn
a great deal from Formula 1, especially in terms of safety.
Dr. Christoph Lauterwasser, a safety expert from the Allianz Centre for
Technology says: “In general, the driving stability decreases as the speed
increases. A force perpendicular to the direction of travel, referred to as
lift, results from the airflow over the top and underside of the car’s body.
As a rule, this lift is in the positive range in passenger cars: it pushes
upwards and tries to raise the car, so relieving the stress on the wheels
and this impairs the stability of the car in the direction of travel. A car
remains easy to control if it has little lift and well-balanced lift
distribution. If they are adapted properly to the car, aerodynamic
accessories such as front and rear spoilers can help to provide better
driving stability and, at times, they can even reduce the air resistance.”
Spoilers or wings are fitted as standard above all on super sports-cars,
where the generally flat and relatively wide design leads to considerable
downforce, but at the expense of the car’s air resistance. Strong downforce
is a crucial safety aspect, especially when taking on curvy roads, where it
can help to stabilise road-holding. But also for “normal” vehicles, there
are special equipment packages for aerodynamic optimisation, which are
offered by most manufacturers. These packages include front and rear aprons,
side sills or rear spoilers.
Low consumption, more safety; the decisive advantages of good aerodynamics
mean that superfluous decorations have very little chance of being featured
in the modern design of passenger cars. Elements such as rear fins, which
were popular in the USA in the 1950s but also widespread in Europe, have
been consigned to the past. In contrast, the development departments of car
manufacturers are constantly trying to achieve lower drag values.
Design studies already exist in which the air resistance of current
passenger cars has been halved. So the cars of the future will have even
less air resistance and lower fuel consumption – to the benefit of the
customers. Moreover, they will also possess a comprehensive aerodynamic
concept, generating downforce to improve driving stability and to increase
safety. |