Aerodynamics Study

Aerodynamics Of F1 Racing Car

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ABSTRACT

The field of aerodynamics is one of the major area of research and development in

modern motor sports. a consequence of the fact that many different avenues that can be exploited in

order to effect continuous improvement of the race cars, possibly the most intensely research area

centers surrounded generation of maximum down force on the car, because it enhances the

performance of vehicle and increase mechanical rate as well as aerodynamic grip and hence lateral

acceleration and braking capacity.

This paper gives the general overview of the aerodynamic consideration in design of

model F1 racing cars. The important of aerodynamic to a modern F1 car is quantified and the effect

of FIA (Féderation Internationale de l'Automobile) regulations on the aerodynamic development of

the racing car is presented and roll of CFD (Computational Fluid Dynamic) and wing tunnel

testing.


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CHAPTER 1

INTRODUCTION

FORMULA ONE, abbreviated to F1 and also known as Grand Prix racing, is the highest class of

single-seat open-wheel formula auto racing. It consists of a series of races, known as Grinds Prix,

held on purpose-built circuits or closed city streets, whose results determine two annual World

Championships, one for drivers and one for constructors. The cars race at speeds often in excess of

300 km/h (185 mph) with engines that produce, as of 2005, around 900 bhp at 18000 rpm. The

sport is regulated by the Féderation Internationale de l'Automobile.

F1 ORIGINS The modern era of Formula One Grand Prix racing began in 1950, but the roots of

F1 are far earlier, tracing to the pioneering road races in France in the 1890s. Through the

Edwardian years, the bleak twenties, the German domination of the 1930s and the early post-war

years of Italian supremacy. And back in 1895

At the birth of racing, cars were upright and heavy, roads were tarred sand or wood,

reliability was problematic, drivers were accompanied by mechanics, and races — usually on

public roads from town to town — were impossibly long by modern standards. Regarded as the

first motor race proper was a 1,200 km road race from Paris to Bordeaux

The competitive advantage over the competitor may be gained from modern F1 car

from relative improvement in one of three key areas; Engine, Tires & Aerodynamics. In general

each competitor receives their engine & tires from external suppliers & hence limited influence as

to development of motor. Aerodynamic is thus biggest area of investment for the formula 1

constructor.

The constructer must obviously take every benefit of its chassis. The chassis must be

light and stiff, be capable of carrying enough fuel, satisfy FIA crash test requirement and offer a good

working environment for the travel. Similarly wings, nose cone angle, and bodywork of the car

generate required downforce. Therefore a better attention in proper design and analysis of these

components.

Similarly the cooling system is critical; it must be reliable and can be considered as part

of aerodynamic package. While all these components are essential to improve the performance of the

car and problem in any of these areas can cause a car to be significantly slower, so for these constructer

is forced to make a large investment in these areas.


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CHAPTER 2

IMPORTANCE OF AERODYNAMICS For all vehicles, ranging from small passengers vehicle to commercial buses and trucks,

reducing air drag is one of the most efficient ways of improving fuel economy. For example, a 5%

improvement in drag for a typical diesel-engine heavy truck, which can simply be achieved by

improving the design of the wing mirrors, can result in fuel saving of hundreds of liters a year for the

typical annual highway driving cycle. On the other end of the scale, in motor racing, fuel saving might

not be the number one priority, but reaching very high speeds certainly is. In order to propel a typical

class 1 ITC racing car at 300km/h, around 30 KW of additional power is required for a car with a drag

coefficient of 0.40, compared to one with 0.36. And when you are operating at the limit of your engine,

this can make the difference between winning and losing. But there is a lot more to external

aerodynamic design than simply reducing the air drag. A typical modern F1 grand prix car has a much

higher drag coefficient than the production vehicle it is based on! This should not come as a big

surprise, especially when looking at all the aerodynamic components and features that are there to keep

racing cars stable and drivable at high speeds, effectively preventing them from flying off the ground.

Components such as front wings, diffuser-shaped underbody, brake cooling ducts, engine intake and

rear wings are there to improve the car’s stability and downforce, which, according to sustain can be at

the same time can add to the drag of the vehicle. Therefore< the optimum aerodynamic design has to

produce the best balance between low drag and high downforce that allows the car to be stable and

drivable at very high speeds.

Aerodynamic has become the most important part of racing during the latest years. It

has nearly become the only way for engineers to gain considerable time on their opponents,

considering the very strict regulation in today’s motor sports. To do so, engineers use wind tunnels to

test their designs.

The primary task of aerodynamicists is to find down force - the vertical force that

pushes cars to the ground by forming a zone of low pressure underneath its wings - and to minimize

drag, the associated longitudinal force that resists the car's forward movement.

2.1 DOWNFORCE

The term downforce describes the downward pressure created by the aerodynamic characteristics

of a racing car that allow it to travel faster through a corner by holding the car to the track or road

surface.


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2.2 PRINCIPLES USED

Two of the most popular explanations existing till today are as follows:

2.2.1 THE LONGER PATH EXPLANATION :

It is also known as the Bernoulli or equal transit time explanation, the popular explanation, path

length or airfoil- shape.

WHAT IS IT?

As air approaches a wing, it is divided into two parts, the part that flows above the

wing, and the part that flows below. In order to create a lifting force, the upper surface of the wing

must be longer and more curved than the lower surface (as shown in fig. 2.2.1). Because the air

flowing above and below the wing must recombine at the trailing edge of the wing, and because the

path along the upper surface is longer, the air on the upper surface must flow faster than the air

below if both parts are to reach the trailing edge at the same time. The "Bernoulli Principle" says

that the total energy contained in each part of the air is constant, and when air gains kinetic energy

(speed) it must lose potential energy (pressure,) and so high-speed air has a lower pressure than

low-speed air. Therefore, because the air flows faster on the top of the wing than below, the

pressure above is lower than the pressure below the wing, and the wing driven upwards by the

higher pressure below. In modern wings the low pressure above the wing creates most of the lifting

force, so it isn't far from wrong to say that the wing is essentially 'sucked' upwards.

WHY IS IT NOT ENTIRELY CORRECT?

There are several flaws in this theory, although this is a very common explanation

found in encyclopedias:

The assumption that the two air particles described above rejoin each other at the

trailing edge of the wing is groundless. In fact, these two air particles have no "knowledge" of each

other's presence at all, and there is no logical reason why these particles should end up at the rear of

the wing at the same moment in time. For many types of wings, the top surface is longer than the

bottom However; many wings are symmetric (shaped identically on the top and bottom surfaces).

This explanation also predicts that planes should not be able to fly upside down, although we know

that many planes have this ability.


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WHY IS IT NOT ENTIRELY WRONG?

The Longer Path explanation is correct in more than one way. First, the air on the

top surface of the wing actually does move faster than the air on the bottom - in fact, it is moving

faster than the speed required for the top and bottom air particles to reunite, as many people

suggest.

Second, the overall pressure on the top of a lift-producing wing is lower than that on

the bottom of the wing, and it is this net pressure difference that creates the lifting force.

2.2.2 THE NEWTONIAN EXPLANATION:

It is also known as the momentum transfer or air deflection explanation, the physics explanation,

PRO-NEWTON or attack angle.

. WHAT IS IT?

Isaac Newton stated that for every action there is an equal, and opposite, reaction

(Newton's Third Law). You can see a good example of this by watching two skaters at an ice rink.

If one pushes on the other, both move - one due to the action force and the other due to the reaction

force. In the late 1600s, Isaac Newton theorized that air molecules behave like individual particles

and that the air hitting the bottom surface of a wing behaves like shotgun pellets bouncing off a

metal plate. Each individual particle bounces off the bottom surface of the wing and is deflected

downward (as shown in fig. 2.2.2). As the particles strike the bottom surface of the wing, they

impart some of their momentum to the wing, thus incrementally nudging the wing upward with

every molecular impact.

. WHY IS IT NOT ENTIRELY CORRECT?

The Newtonian explanation provides a pretty intuitive picture of how the wing

turns the air flowing past it, with a couple of exceptions:

The top surface of the wing is left completely out of the picture. The top surface of a

wing contributes greatly to turning the fluid flow. When only the bottom surface of the wing is

considered, the resulting lift calculations are very inaccurate. Almost a hundred years after

Newton's theory, a man named Leonhard Euler noticed that fluid moving toward an object would

actually deflect before it even hits the surface, so it doesn't get a chance to bounce off the surface at


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all. It seemed that air did not behave like individual shotgun pellets after all. Instead, air molecules

interact and influence each other in a way that is difficult to predict using simplified methods. This

influence also extends far beyond the air immediately surrounding the wing.

. WHY IS IT NOT ENTIRELY WRONG?

While a pure Newtonian explanation does not produce accurate estimates of lift

values in normal Flight conditions (for example, a passenger jet's flight), it predicts lift for certain

flight regimes very well. For hypersonic flight conditions (speeds exceeding five times the speed of

sound), the Newtonian theory holds true. High speeds and very low air densities, air molecules

behave much more like the pellets that Newton spoke of. The space shuttle operates under these

conditions during its re-entry phase. Unlike the Longer Path explanation, the Newtonian approach

predicts that the air is deflected downward as it passes the wing. While this may not be due to

molecules bouncing off the bottom of the wing, the air is certainly deflected downward, resulting in

a phenomenon called downwash.

The above principle that allows an airplane to rise off the ground by creating lift

under its wings is used in reverse to apply force that presses the race car against the surface of the

track. This effect is referred to as "aerodynamic grip" and is distinguished from "mechanical grip,"

which is a function of the car's tires and suspension. The creation of downforce can only be

achieved at the cost of increased aerodynamic drag (or friction), and the optimum setup is always a

compromise between the two. Downforce is necessary for maintaining speed through corners. Due

to the fact that the engine power available today can overcome much of the opposing forces

induced by drag, design attention has been focused on first perfecting the down force properties of

a car then addressing drag. The aerodynamic setup for a car can vary considerably between

racetracks, depending on the length of the straights and the types of corners; some drivers also

make different choices on setup. Because it is a function of the flow of air over and under the car,

downforce typically rises with the speed of the car and requires a certain minimum speed in order

to produce a significant effect. .

The amount of downforce that can be created is typically much greater for an open-

wheeled Formula One or Indy car than for a full-bodied touring car or stock car because of its

enhanced aerodynamic characteristics and the use of wings rather than spoilers.

Two primary components of a racing car can be used to create downforce when the

car is travelling at racing speed reshape of the body, and wings uses airfoils.


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2.2.3 GROUND EFFECT

Downforce is available by understanding the ground to be part of the aerodynamic

system in question. The basic idea is to create an area of low pressure underneath the car, so that the

higher pressure above the car will apply a downward force. Naturally, to maximize the force one

wants the maximal area at the minimal pressure. Racing car designers have achieved low pressure in

two ways: first, by using a fan to push air out of the cavity; second, to design the underside of the car

as an inverted aerofoil so that large amounts of incoming air are accelerated through a narrow slot

between the car and the ground, lowering pressure by Bernoulli's principle. [Ref. 1]


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CHAPTER 3

DESIGN CONSIDERATIONS FOR AN AERODYNAMIST

The main factor which separates the victors from the valiant in this area is the

aerodynamic performance - too much drag and you're pulling unwanted air along with you. It is

in efficiency where the skills of the aerodynamicist are tested to the full. He must obtain as much

downforce as he can without creating too much drag, and slowing the car. .

It is important to note that top speed is important to have, but it's generally more

important to get around the corners fast. It is here that the most important Formula One trade-off

takes place. Forget all other; this is F1 in a nutshell - Fast or Nimble? To go forward fast, you must

aim to minimize drag. To corner fast, you must maximize down force (to maximize the grip on the

racetrack). Unfortunately, downforce comes at a price - the price of additional drag! Cars can be

lightening on the straight, yet be a second down on lap time. Why? The engineers haven't balanced

the level of downforce and straight-line speed required.

Cornering is critical. A car will have to decrease its speed to go from a straight,

around a corner, and onto another straight. The ability to go around this quickest is paramount in a

successful car. A decrease in speed must be re-claimed once back on the straight, so the car that

loses the least speed will have to accelerate the least when back on the straight - and accelerating

takes time.

The design of this corner will, to a point, limit the car's speed around it. The other

factor is the cornering ability of the car. To take a corner like Copse at Silverstone in a Formula

Ford car would be very different to doing it in an F1 machine due to the difference in design

between the two vehicles. Even taking it in two different Formula One cars would have different

effects. The competence of a car in cornering comes in part from the height of the centre of gravity.

This is the point through which the weight of the car is seen to act, or the point

where the car would balance on a pivot l. Designers want the centre of gravity in a race car low to

the floor. Other major criterion in cornering is the design of the suspension and tires, the load

transfer characteristics, and the downforce on the car.

All the above discussions are coupled together, and fit under the banner of

'Drivability'. The designer strives for this, and it must be the biggest dagger a driver places in the

designer's heart when he claims the car is 'undividable'! Along with all those factors described


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previously, the relationship between the centre of gravity and the aerodynamic centre is crucial for

a driver's confidence.

The “aerodynamic centre” is similar to the centre of gravity in definition. It is the

point through which the force created by the aerodynamics is seen to act. The fuel, which is the

only part of the car to change weight significantly during the race, is positioned in such that the

centre of gravity doesn't move significantly. However, the aerodynamic force is constantly

changing, so keeping the aerodynamic centre in the same place throughout a lap is a near

impossible task. As the car is so close to the ground, millimeters of ride height (distance between

the car and the ground) change downforce levels significantly. If the front is closer to the ground

than the rear (as in braking), there will be more downforce on the front than normal, and the

aerodynamic centre will move forward. In contrast, accelerating lifts up the front, and the aero

centre moves back. To the driver, this movement feels unsettling, so the more level the car can be

through accelerating, braking, cornering, and over the bumps, the more controllable it will be. For

that reason, suspension stiffness is also important, as are load transfer characteristics. [Ref. 6]

The complexities of compromises between all of these factors make the difference

between the car being fast, and the team being furious!


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CHAPTER 4

AERODYNAMIC FEATURES OF F1 CARS

4.1 BODY (WORK)

The general shape of body is like a “Boat “and In general the body of f1 car can

thought as a Bluff Body close to ground, with large wake and associated form drag. [Ref. 1]The

teardrop shape, previously discussed, displays ideal aerodynamic properties in an unconstrained

flow and is well suited for aeronautical applications. However, when this shape is incorporated into

the design of an F1 vehicle, it is subjected to constrained flow, which causes different flow

behaviors. This is due to the simple fact that these cars are very close to the ground. The presence

of the ground prevents the formation of a symmetrical flow pattern .The results of this flow

behavior are an unfavorable increased drag coefficient and generation of a very favorable

downforce. The rounded and tapered shape of the top of the car is designed to slice through the air

and minimize wind resistance. Detailed pieces of bodywork on top of the car can be added to allow

a smooth flow of air to reach the downforce creating elements (i.e., wings or spoilers, and

underbody tunnels). The underside of the body is similar in shape to an inverted wing and creates

an area of low pressure between the car and the track, pressing the car to the road. This is

sometimes called a ground effect and has been the subject of many rule changes over the years in

different racing series. [Ref. 3]

4.2 FRONT WING

Front wing aerodynamics is one of the most complex elements of Formula One car

aerodynamics. Through the history of Formula One, the front wing has developed from a simple

single element wing into a highly three-dimensional, multi-element high lift device (as shown in

fig.4.2.1). [Ref.2] Endplates are sophisticated, which avoid the spoiling of air and influence the

performance of the front wing. The most obvious function of a front wing is to produce downforce

on the front end of the car. The wing itself generally produces approximately 25 – 30 % of the total

car downforce. [Ref.1] beside its contribution to the overall downforce, the front wing also works

as an adjustable counterbalance to the rear wing load. A front wing system is placed on the front-

end of a car also regulate the air flow over the entire car (as shown in fig. 4.2.2) and as the foremost

device that disturbs the incoming (from the car point of view) airflow, it prevents the rest of the car

to see a preferable ‘clean’ flow as a by-product of this is high downforce production. [Ref.3] The

performance of the front wing is also strongly dependent on the presence of the front wheel. A


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rotating wheel produces strong crosswise flow areas close to the ground in front of the wheel due to

a squeezing or jetting effect. These jet vortices are highly influential in understanding the form of

the front wing wake, and their effect changes by the end plates. [Ref.2]

On each end of the wing as well as nose cone is made symmetrical and provided

with endplates. The height of front wing is reduce nearer to the nose cone as this allows air to flow

into the radiators and to the under floor 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. [Ref.3] the asymmetrical shape also allows a better airflow to the under floor and the

diffuser, increasing downforce. This again allows a slightly better airflow to the under floor

aerodynamics and help in producing ground effect. By means of a ground effect, this was

particularly interesting for front wings because if would increase downforce at high speeds without

an increase of drag.

4.3 NOSE CONE

The nose cone is nothing but the front edges of the formula1 racing car (as shown in

fig. 4.3.1) the height of nose cone plays an important role in case of f1 car design.

The main advantages of a higher nose need some thinking and knowledge of the

complete car to see. At first sight the higher nose is equal to less downforce as by itself it pushes

less air up over the nose. In recent cars surprisingly the nose is not aimed to push air up, but instead

small at the front to allow airflow aside of the nose. The air that passes the nose forms the basic

concept of a high nose cone. Having such a nose allows air to go straight through under the nose

instead of having to bend around it. While it reduces drag for sure, the front wing planes can span

the complete width of the car, which in fact allows more downforce to be generated at the front. All

air that passed under the nose is then guided under the car or split to either side of the car by the

splitter located just in front of the side pods. [Ref. 3]

Why now would we want so much air to nicely pass the nose and go into the side

pods or under the car's floor? Quite simply where the most downforce can be generated, exactly the

diffuser that locates at the end of the car's stepped floor. The more air you get under the floor and

the faster it can exit out of the diffuser the more downforce will be generated. The advantage of

such a floor is even more obvious as downforce is generated not only in the diffuser but also under

the complete floor.


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But the sky is not all blue as there are also some disadvantages to it. The nose itself

of course does not generate much downforce; in fact the higher the noses point the less downforce

by itself (this does not include any downforce generated by front wing or floor). Another

disadvantage for the highest noses may be visibility from the driver's point of view. The main

advantages of a higher nose need some thinking and knowledge of the complete car to see.

4.4 REAR WING

The actual model of rear wing is as shown in fig. 4.4.1) it is mounted at rear side of

the car.

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. [Ref. 1] 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 car. The working principle of rear wing is (as shown

in fig.4.4.2) the 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. [Ref. 2] 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.

At either end of the wing are the end-plates are provided which serve two purposes.

The first purpose of the end plates is to prevent tip losses on the wing. Tip losses occur due to

higher-pressure air on the upper surface of the aerofoil moving around the tip of the aerofoil to the

lower pressure under surface of the aerofoil. This can provide a significant contribution to drag and

is a common problem on transport aircraft where the problem is minimized using winglets. The

second purpose that the end plates serve is to prevent interference from the rear wheels. [Ref. 4]

The wheels make the biggest contribution to the drag than any other component on the car and the

regulations prevent them from being encased by body work. The air around both the front and the

rear wheels is very turbulent and therefore it is not desirable to have this highly turbulent air flow

interfering with the relatively smooth flow over the rear wing and reduces the performance of the

rear wing and also increases the drag force which limits the top speed of the car.


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4.5 DIFFUSER

The smallest thing that you can count to the wings part is the diffuser. Actually, it

does exactly the opposite of a rear or front wings. Instead of pushing the air up, it sucks the air up.

The volume of the diffuser increases towards to the end of the car. (As shown in fig. 4.5.1) Where

a certain amount of air molecules filled increases for example initially 1dm³ under the car, these

now fill 2dm³. This drop of pressure causes a car to be sucked towards the ground. Driving at a

speed of 300 km/h, the ground effect of the car would be extreme if there was no air under the car

itself. Therefore, the FIA has forbidden strokes and sloping car bottoms because of safety reasons.

[Ref. 7] Instead of raising the back of the car, the diffuser sucks the air away from under the car

because the low pressure. The diffuser use placed under the rear wing and is actually a sweep up of

the car's floor. It consists of many tunnels and spoilers (as shown in fig. 4.51), which carefully

control the airflow to maximize this suction effect. The design of the bottom of the car, and thereby

the diffuser is a critical area, because it can greatly influence the car's behavior in corners. More

importantly, the designers have to be care full that the car keeps working well in all circumstances,

and at any distance from the ground. Losing all of the diffuser's generated downforce when riding

over a curb will greatly generate a nervous behavior of the car itself. The strokes and flips witching

the diffuser have lately become that advanced (curbed and even foreseen by gurney flaps

sometimes) that any track distance is insufficient to guarantee good performance. It is still a part

where a lot of time can be gained on current F1 cars, partly by pulling more air towards the diffuser

by inducing the coke-bottle effect.

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. [Ref. 5] 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 large then the flow will separate because of the adverse

pressure gradient.


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Although wings and diffusers work similarly, they are based under different

concepts. A diffuser serves to eject air out from the underside of the car. This pulling action

increases the velocity of the air below the car, so that the more slowly moving air above the car will

push the car into the ground. Diffusers, when working properly, can be extraordinarily important to

the aerodynamics of a car. When F1 cars travel around the track, the diffusers produce 40 % of the

total downforce. When not working properly, these devices can befuddle even the best-experienced

drivers. [Ref. 1]


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CHATER 5

STEPS IN THE RACE CAR DESIGN PROCESS

The car design is carried out using basic aerodynamic principles. Simulating Race

Car Design with “Computational Fluid Dynamics” After this a physical scale model of the car and

place it in a “wind tunnel”, where the teams can conduct further research and continue to assess the

car's aerodynamic efficiency. After these two steps are completed, the final step is to test and assess

the car on the track itself.

5.1 CFD (Computational Fluid Dynamics)

It is a computational technology that enables you to study the dynamics of things

that flow. Using CFD, you can build a computational model that represents a system or device that

you want to study. Then you apply the fluid flow physics and chemistry to this virtual prototype,

and the software will output a prediction of the fluid dynamics and related physical phenomena.

Therefore, CFD is a sophisticated computationally based design and analysis technique. [Ref. 10]

5.1.1 The CFD Process

There are essentially three stages to every CFD simulation process: preprocessing,

solving and post processing.

a) PREPROCESSING

This is the first step in building and analyzing a flow model. It includes building the

model within a computer-aided design (CAD) package, creating and applying a suitable

computational mesh, (as shown in fig. 5.1.1) and entering the flow boundary conditions and fluid

materials properties.

b) SOLVING

The CFD solver does the flow calculations according to the given boundary

condition and produces the results on the screen.

c) POSTPROCESSING

This is the final step in CFD analysis, and it involves the organization and

interpretation of the predicted flow data and the production of CFD images and animations. Post

processing tools enable to provide several levels of reporting, so one can satisfy the needs and


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interests of all the stakeholders in design process. Quantitative data analysis can be as sophisticated

as per the requirement. High-resolution images and animations help you to tell story in a quick and

impact manner.

5.2 WIND TUNNELS

Racing teams have been devoting more and more time to the development of the

aerodynamics of their cars. They have done so (and they still do it) with track and wind tunnel

testing. Track testing is widely recognized for being too expensive and dependent on many casual

events. The advantage, of course, is that the car is tested in its actual configuration in a real world

situation.

The wind tunnel is the technical answer of the aerodynamic engineers. The wind

tunnels are now days very sophisticated, and allow a wide range of studies, including modeling of

the car in complete configuration, ground plane simulation, etc. [ref.1] It consists of a huge fan. The

main fan has a blade diameter of over 5m and is powered by a 3,000 horsepower electric motor,

generating a torque of 32,000 ft-lb at 500 rpm. In total there are 16 rotating blades and 27 stator

blades - non-rotating blades that are a structural part of the fan construction. This fan will move

around 1000 m3 of air per second so we'll be getting wind speeds of 80 m/s in the test section a

good chance of working before they enter the wind tunnel. [Ref.10]

5.2.1 Tunnels with Moving Ground

One major advancement has been promoted by the use of moving ground planes

(previously not used in other branches of aerodynamics). When in the 1970s it was discovered that

downforce could be created by means of ground effect, it became essential to simulate the effect of

the track on the car performance (on underbody, side pods, exposed wheels, wings).

In a wind tunnel with a stationary ground plane a boundary layer build up under the

car, and can interfere with the boundary layer of the lower components. Such a case cannot give the

correct answer. There are several ways to remove the ground boundary layer, but the most effective

method is to use a moving belt, with the wheels rotating with the belt. The simulation of rotating

wheels could not be more effective. The importance of the exposed wheels in Indy and Formula 1

has been widely recognized, and neglecting this effect may have a large effect on the overall

performances. [Ref. 10]


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CHAPTER 6

LATEST DEVELOPMENTS

The 2008 Formula One World Championship will usher in a new fan-friendly year

for the sport. Following agreement by the Formula One Commission, new proposals, including a

revolutionary twin-wing concept, will ensure that futureF1 cars will be able to overtake more

easily, have more mechanical grip and run on slick tires.

According to the recent FIA/AMD survey, where over 93,000 fans gave their

opinion, the vast majority (94%) wants to see more overtaking. This is why the FIA and its research

team came up with a proposal for a radical new wing to make more overtaking possible .The

problem has been that most aerodynamic research aims to improve car’s performance when running

in what is known as ‘clean’ air which has not been disturbed by the wake of a car in front. (As

shown in fig. 6.1.2) However, in race conditions when cars follow each other closely, the wake of

one car significantly reduces the aerodynamic performance of the following car, making overtaking

extremely difficult and often impossible. To combat this problem the FIA initiated programmed of

research, which looked into improving aerodynamic performance when a car is trying over take.

With the help of the FIA’s technology partner AMD, the research team came up with the concept of

a Centre line Downwash Generating.

The CDG wing is a split rear wing designed to generate a wake of non-turbulent air

allowing the following car to run close to the car in front without loosing downforce on the front

wing. (CDG) wing (as shown in fig.6.1.1)

The proposal met with broad approval by the Formula One Commission and was

ratified by the FIA World Motor Sport Council. The commission also agreed a proposal for tires to

be supplied by a single manufacturer. As such, the CDG Wing, together with wider wheels and

slick tires, will form part of the 2008 FIA Formula One Technical Regulations. [Ref. 7]


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CONCLUSION

Thus we see that aerodynamics play a vital role in design of formula-1 cars where

speed is of utmost importance various features like the spoilers, CDG wing, diffuser all aid in this

quest to achieve minimum air resistance to the car (i.e. reducing the drag but at the same time

improving on the cornering speed and the dowforce. The FIA changes the rules every year to

ensure drivers safety and also to make the race ever interesting. Technology changes As a result of

the changing rules, there are changes in car design and laying paths for new technology.


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Fig. 4.2.1 Actual Model of Front Wing

Fig. 4.2 .2 Air Flow Regulation Over The Car

Fig. 4. 3. 1 Nose Cone

Fig .4.4.1 Actual Model of Rear Wng.


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Fig. 4.4.2 Working Principle of Rear Wing.

Fig. 4. 5.1 Actual Diffuser Model.

. Fig. 4.5.2 Working of Diffuser.


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Fig. 6.1.1 F1 Car With CDG Wing.


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Fig. 5.1.1 Schematic of a CFD simulation process on a F1

Racing Car CAD .Grid.


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INDEX

SR NO. TOPIC PAGE NO

1 INTRODUCTION……………………………….…………..…...1 2 IMPORTANCE OF AERODYNAMICS………….…….....…...3

2.1 DOWN FORCE………………..….…….…....4 2.2 PRINCIPLES USED…………………............4

2.2.1 LONGER PATH EXPLANATION….…......4 2.2.2 NEWTONIEN EXPLANATION……….…..5

2.3 GROUND EFFECT……………………....…..7 .

3 DESIGN CONSIDERATION FOR AN AERODYNAMICS…………………………………………….....8

4 AERODYNAMIC FEATURES OF F1 CAR…………...…..….10

4.1 BODY(WORK)………………...………...…..10 4.2 FRONT WING…………………….…………10 4.3 NOSE CONE……………………..…….....….11 4.4 REAR WING………………………..…..……12 4.5 DIFFUSER………………………..……..…...13

5 STEPS IN CAR DESIGNING PROCESS………………….…..15

5.1 COMPUTATIONAL FLUID DYNAMI....….15 5.1.1 CFD PROCESS……………….………….…15

5.2 WIND TUNNEL………...……………..….....16 5.2.1 TUNNEL WITH MOVING GROUND….....16

6 LATEST DEVELOPMENT……..……………………………...18

7 CONCLUSION…………………………………………………..19

8


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ABSTRACT

The field of aerodynamics is one of the major areas of research and development in

modern motor sports. a consequence of the fact that many different avenues that can be exploited in

order to effect continuous improvement of the race cars, possibly the most intensely research area

centers surrounded generation of maximum down force on the car, because it enhances the

performance of vehicle and increase mechanical rate as well as aerodynamic grip and hence lateral

acceleration and braking capacity.

This paper gives the general overview of the aerodynamic consideration in design of

model F1 racing cars. The important of aerodynamic to a modern F1 car is quantified and the effect

of FIA (Féderation Internationale de l'Automobile) regulations on the aerodynamic development of

the racing car is presented and roll of CFD (Computational Fluid Dynamic) and wing tunnel

testing.

Aerodynamics Study

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