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F1-ENGINEER |
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| F1-Aerodynamics |
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| Aerodynamics
Features of the F1 Vehicle |
| Front wing and nose cone
assembly |
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The front wings on the car can produce 25-40% of the cars
downforce.Each front aerofoil is made a mainplane (1) running
almost the whole width of the car suspended from the nose (4).
Onto this are fitted two aerofoil flaps (2), one on each side,
which are the adjustable parts of the wing. These flaps are
usually made of one piece of carbon fiber, but Ferrari has used
two small flaps rather than one large one. On each end of the
mainplane there are endplates The wing flap on either side of
the nose cone is asymmetrical. It reduces in height nearer to
the nose cone as this allows air to flow into the radiators
and to the underfloor aerodynamic aids. If the wing flap maintained
it's height right to the nose cone, the radiators would receive
less airflow and therefore the engine temperature would rise.
The asymmetrical shape also allows a better airflow to the underfloor
and the diffuser, increasing downforce. The wing mainplane is
often raised in the center. This again allows a slightly better
airflow to the underfloor aerodynamics, but it also reduces
the wings ride height sensitivity |
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| Front wing of the 2000
Ferrari |
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Over time, as the wheels were moved closer to the chassis,
the front wings overlapped the front wheels when viewed from
the front. This created unnecessary turbulence in front of the
wheels, further reducing aerodynamic efficiency and thus contributing
to unwanted drag. To overcome this problem, the top teams made
the inside edges of the front wing endplates curved to direct
the air towards the chassis and around the wheels. Many teams
later introduced sculpted outside edges to the endplates to
direct the air around the front wheels. This was often included
in the design change some teams introduced to reduce the width
of the front wing to give the wheels the same position relative
to the wing in previous years. The interaction between the front
wheels and the front wing makes it very difficult to come up
with the best solution, and consequently almost all of the different
teams have come up with different designs |
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The relationship between the front wing and the track is a
delicate one; with the wing generally being more efficient the
closer it is to the track. Therefore, the front
wing is low to the ground to obtain as much advantage from ground
effect as possible, and generally has one full spanning flap.
Developments usually concentrate on the profile of the wing,
and the use of flaps. However, Ferrari recently angled the leading
edge of the wing to form a forward racing V-shape. This comes
from flow
visualizations on the wing, which shows its suction power is
so strong that it pulls air in from angles not straight with
the centerline. This means that the air is approaching a normal,
straight leading edge at an angle to it, and therefore not working
the wing to its full potential. By turning the edge by the correct
angle, maximum efficiency will be obtained.The part of the front
wing, which tends to change most in design, is the endplate.
The primary function of this feature is to stop
the high-pressure air on the top of the wing from being encouraged
to roll over the end of the wing to the low-pressure air beneath,
causing induced drag. Additionally, the design aim of the endplates
is to discourage the dirty air created by the front tire from
getting under the floor of the car. Further to these, some teams
use 'splitters', which are vertical fences, attached to the
undersurface of the front wing, to assist the endplate |
| Wheels |
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The wheels of a formula one car probably induce the most drag
of any part of the car.Unfortunately, have yet to be redesigned
to reduce aerodynamic drag.Hindering this innovation are certain
technical regulations.One such regulation is that the wheels
cannot be covered.F1 wheels must to be the shape they are and
this causes separation behind them.This separation causes large
amounts of form drag.The amount of generated skin friction drag
is minimal in comparison.So far, it appears that not much can
be done to reduce form drag on the wheels, however teams have
used the front wing to try to deflect the oncoming air around
the front tires. |
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| Suspension |
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In recent years, suspension members have been streamlined
into an aerofoil shape. According to the rules however, they
are not allowed to produce downforce, and are simply shaped
that way to reduce drag, and to keep the flow heading for the
sidepods relatively undisturbed. The suspension arms are a good
example, as they are often made in a shape of a wing, although
the upper surface is identical to the lower surface. This is
done to reduce the drag on the suspension arms as the car travels
through the air at high speed. Consider Figure . In the lower
diagram, A, represents an unstreamlined suspension arm, the
lower one, B, a suspension arm with an aerodynamic covering.
Both have roughly the same cross sectional area, but the lower
case has a drag force ten times less than A.
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| Barge Boards |
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These devices were first seen in 1993 and their purpose is
to smooth the airflow around the car and into the radiator intakes.
They are most commonly mounted between the front wheels and
the sidepods (See Figure .Their main purpose is to direct relatively
clean air into the sidepods.Clean air is from the low section
of the front wing where airflow is fairly unaffected by the
wing and far away from tires, which may throw stones and debris
in to the radiator.
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| Brake Cooling |
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Brake cooling is vital in today’s Formula 1, because
of the extreme heat produced.Modern racecar brakes can heat
up until they are red hot.They can easily be destroyed at such
extreme temperatures.This is where aerodynamics comes into play
with the addition of small air intakes to bring cooling air
to the brakes.They can be seen in the pictures below.These intakes
actually change between races, since the braking requirements
of each track are quite different |
| Rear Wing |
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The rear wing is a crucial component for the performance of
a Formula One racecar.These devices contribute to approximately
a third of the car’s total down force, while only weighing
about 7 kg.10Figure shows a rear wing.Usually the rear wing
is comprised of two sets of aerofoils connected to each other
by the wing endplates.The upper aerofoil, usually consisting
of three elements, provides the most downforce, therefore varied
from race to race.The lower aerofoil, usually consisting of
two elements, is smaller and provides some downforce.However,
the lower aerofoil creates a low-pressure region just below
the wing to help the diffuser create more downforce below the
carThe rear wing is varied from track to track because of the
trade off between downforce and drag.More wing angle increases
the downforce and produces more drag, thus reducing the cars
top speed.So when racing on tracks with long straights and few
turns, like Monza, it is better to adjust the wings to have
small angles.Conversely, when racing on tracks with many turns
and few straights, like Austria, it is better to adjust the
wings to have large angles.Figure shows a comparison of wings
on the Ferrari F1-2000 for two different tracks.The section
on the left shows Michael Schumacher in Austria while the section
on the right shows Ruebens Barrichello in Monza.The section
on the left clearly shows an increased wing angle compared to
the section on the right.
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| Rear Wing II |
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Splitting the aerofoil into separate elements as seen in is
one way to overcome the flow separation caused by adverse pressure
gradients. Multiple wings
are used to gain more downforce in the rear wing. Two wings
will produce more downforce than one wing, but not twice as
much. Figure shows the relationship between the number of airfoils
with both the lift coefficient and the lift/drag ratio. The
lift coefficient increases and lift/drag ratio decreases when
increasing the number of aerofoils. The position of the wings
relative to each other is important. If they are too close together,
the resultant forces will be in opposite directions
and thus cancel each other. |
| Rear Wing Endplates |
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Rear wing endplates are designed with form and function in
mind. Because of their form they provide a convenient and sturdy
way of mounting wings. The
aerodynamic function of these endplates is to prevent air spillage
around the wing tips and thus they delay the development of
strongly concentrated trailing vortices.
Trailing vortex or induced drag is the dominating drag on rear
wings. An additional goal of the rear endplates is to help reduce
the influence of upflow from the
wheels. Figure 22 shows a rear wing endplate on the 2000 season
McLaren MP4-15. Figure shows a rear wing endplate on the 2000
season British American
Racing BAR-002. There is a U-shaped cutout from the endplate
that further alleviates the development of trailing vortices. |
| Diffuser |
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The diffuser is usually found on each side of the central
engine and gearbox fairing and is located behind the rear axle
line as seen in Figure.As seen in Figure , the diffuser consists
of many tunnels and splitters.It is designed to carefully guide
and control airflow underneath the racecar. Essentially, it
creates a suction effect on the rear of the racecar and pulls
the car down to the track.The suction effect is a result of
Bernoulli’s equation, which states that where speed is
higher, pressure must be lower.Therefore the pressure below
the racecar must be lower than the pressure at the outlet since
the speed of the air below the racecar will be higher than the
speed of the air at the outlet.Racecar engineers must carefully
design the diffuser, since its dimensions are limited by the
racing regulations and its angle of convergence is somewhat
restricted.If the angle of convergence is too great then the
flow will separate because of the adverse pressure gradient.
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| Chimneys |
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Chimneys are an aerodynamic feature recently debuted during
the F1 2000 season.Many of the top teams like McLaren, Ferrari,
and BMW Williams have experimented their use.As seen in Figure
the chimneys are mounted on the cooling sidepods.The primary
function of chimneys is to provide additional cooling to the
engine.This is accomplished by creating a pressure gradient.The
increase in speed of the air over the chimney creates a low-pressure
region that sucks out air from the sidepods to aid the radiators
in cooling the engine.Many different versions of chimneys were
designed for the 2000 season.Figure shows Ferrari’s version
of the chimney . |
| Flip-Ups |
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Lift due to exposed wheels is a major problem
for F1 racecars since regulations prohibit enclosing the wheels
within the bodywork.Exposed wheels generate upward lift forces
that decrease the downforce created by the wings and other
structures.This positive lift may reduce downforce by approximately
11% on a typical F1 track.1To alleviate this problem, engineers
design flip-ups on the rear section of the sidepods, in front
of the rear tires.Flip-ups as seen in Figure guide air over
the rear wheels while creating some downforce.
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