rce-1

Race Cars Technical Competition Journal ; www.racecarsengineering.com 

raceCARS 

engineering 

Aero Post Rig Course - 1 

Power Unit: explanation 

1 

Fan cars: What's it all about 

Aero Post Rig Analisys; improving Damper 

GP3 — Setup Optimization 

Disperssion Contaminants - Sample CFD 

Low Cost Sport Car design - 1 

1

Journal of Technical Race Cars Competition ; www.racecarsengineering.com 

Staff 

Timoteo Briet Blanes 

info@tecnicaf1.es 

Linkedin: https://www.linkedin.com/in/timoteobriet 

Twitter: https://twitter.com/tecnicaf1 

Romina Re 

Cover Designer: Juan David Barrera García ( @erteclas ) 

2


INDEX 

Pag. 8 

AERO POST RIG COURSE — 1: Timoteo Briet, Enrique Scalabroni, Ignacio Suárez; 

Translation Elvira Miguel Peña; Revision David Rodríguez Martínez, Ruyman de la Cruz Fariña 

Pag. 39 

Pag. 44 

POWER UNIT: EXPLANATION: Timoteo Briet Blanes, Roberto Alvarez (Nebrija University); 

Translation: Jorge Tornay Carpintero 

FAN CAR: WHAT´S IT ALL ABOUT: Josep Carbonell Oyonarte 

Pag. 53 

Pag. 56 

AERO POST RIG ANALISYS: IMPROVING DAMPER: Enrique Scalabroni, Ignacio 

Suárez and Timoteo Briet 

GP3 — SETUP OPTIMIZATION: Ignacio Suárez Marcelo 

Pag. 70 

DISPERSSION CONTAMINANTS; Iñaki Veci 

Pag. 75 

LOW COST SPORT CAR DESIGN — 1: Sergio Corbera Caraballo, Timoteo Briet Blanes 

ADVERTISINGS 

Nebrija Engineering Services Scan 3D, Aerodynamics and CFD: Pag. 6 

Course Aerodynamics and CFD: August 2015: Pag. 74 

Engineering Competition MASTER: Nebrija University: Pag. 79 

3


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4


TRANSLATIONS 

and 

COLABORATIONS 

Translations: 

Elvira Miguel Peña: Article: Aero Post Rig — 1 

Jorge Tornay Carpintero: Article: Power Unit: Explanation 

Industrial engineering student and this year finish the final project. Has done a 

course on aerodynamics and CFD simulation. Has been awarded a scholarship the 

last two years at the Antonio de Nebrija University. Has done a diploma in automotive 

for four years at the University and has built an Austin Mini ‘63 with a 

Suzuki Hayabusa engine during the academic year. Assistant in the rally of the 

Spanish association of Ferrari's owners, among other things related to this and 

other sector. 

Revisors: 

Ruymán de la Cruz Fariña: Aero Post Rig — 1 : Revisor 

Ingeniero Técnico Industrial Mecánico y estudiante de Física en la Universidad de 

La Laguna. Actualmente centrado en la dinámica vertical de vehículos: interacción 

aerodinámica/suspensión y su implementación en un software. 

David Antonio Rodríguez Martínez: Aero Post Rig — 1 : Revisor 

Ingeniero Industrial con especialidad en Mecánica por la Universidad de Vigo. 

Actualmente trabaja en como R&D en un grupo de investigación de la Universidad 

de Vigo. Especializado en simulaciones CFD, tanto con software comercial como 

libre, y diseño CAD. Entre sus proyectos se encuentran el análisis del proceso de 

temple y otros tratamientos de enfriamiento controlado de piezas de automoción 

mediante CFD y el rediseño completo de maquinaria ferroviaria. 

5


SERVICES SCAN 3D 

REVERSE ENGINEERING 

CLOUD POINTS TO SURFACES CAD —> TO CFD SIMULATION 

AERO MAP CREATION 

AERODYNAMIC STUDY 

IMPROVE 

ETC…. 

6


CFD SIMULATION SERVICES 

7


AERO POST RIG ANALISYS — 1 

THANKS 

I would like to thank all my family for everything she has done for me, and for instilling in me my passion for 

science. 

I also thank them for their eternal patience and for putting up with me. 

Finally, I want to thank and remember all those who are no longer here; I know that, wherever they may be, 

they may like to know that we remember them. 

As my nephew Jordi said, wherever they may be, we hope that they take care of them, like they have taken 

care of us. 

All of us are a result of our loved ones and our experiences. 

Every white hair we may have, every new pain we may suffer, everything that we cannot do as before, and 

every friend and relative that may not be with us anymore, will be a sign of having lived and, hopefully, loved. 

For you, dad, you left suddenly two months ago, without saying anything, without taking leave and saying 

you that I love you; thank you for everything. 

Timoteo Briet Blanes 

8


PREFACE-1 

Timoteo Briet: a tireless and tenacious passionate: 

I have always known Timoteo joyful and vehement. Nevertheless, with this vitality, he has never missed the 

opportunity of any employment circumstance for living intensively the discovery or research process of getting into 

some of the tens of ideas he comes up with. Nor has he neglected his facet as a teacher, his ease to transmit 

knowledge, his contagious way to make the interlocutor discover, in some cases the beauty of technical or mathematical 

construction, in other, the pride for a brilliant application or a wonderful result invented by him facing a considered 

challenge, nor in the classroom, neither in the conversations and debates. 

His magnificent curiosity and his astonishment capacity facing any scientific facet or observation of natural 

phenomenon have made him living his life in a clever and intense way. 

Undoubtedly, his genes have provided him a complex mind, ready to relate different phenomenon and theories, 

but his environment has motivated and induced him that so special way of being and living, so sensitive with the 

routine things and so generous with the others. 

He presents now the result of the last years of his professional life: a manual of his specialty, when it looked 

as manuals were a threatened species. Scientific media are joining the current of supreme specialization, the publication 

of articles with partial subjects or the oral spreading in courses or specialized conferences. There is a need not 

only to dominate and cover the entirety of knowledge of a scientific area and keep abreast of publications and articles, 

but also living the many times hidden tough practice of having faced up with recently considered problems by the 

technique urgency is necessary. 

Timoteo Briet has known how to integrate the search of the researcher excellence, making it simultaneous 

with the creation of an environment which is favorable to business innovation and endeavor. It is not usual that someone 

who gets quickly a very specific PhD, leaves his academic life of Mathematics Professor to have the entrepreneur 

solitude and the walls that rise ahead. 

A few brilliant teachers like him leave, even temporarily, the strength and calm of scientific institutions. He 

works, with his own resources, for systematic cooperation between scientific production of new knowledge and professionals 

or entrepreneurs that are dedicated to applying it. 

It is often argued that both the recovery from the current crisis and the economic strength of a country are 

closely linked to its capacity for innovation and invention. 

The vitality of a country, in addition to investments, requires a change of mentality and a determined belief in 

science, because without it, nor the industrial revolution nor the technological revolutions would not have been possible. 

Undoubtedly, progress would not be possible without people like Briet, with his disposition to cooperation and 

without institutions for his research. 

9


Each person has his own way to reach the happiness. Some need expensive complements that cannot be 

reached by majority to be happy. Others, such as Timoteo, are happy with small and, even, with ephemeral. The other 

day, seeing a bus, that I designed, driving around the city, I was immensely happy, he recently told me with that sparkle 

in his eyes that expressed his vitality and emotion. He had proposed a new design calculated in his wind tunnel, of 

a traveler bus, and the manufacturers of the Hispano Carrocera had taken. This Timoteo, who imagines and sees the 

beauty of the turbulences, who calculates fairly precisely in direction and composition the evolution of the plume of a 

pollutant chimney, who lives the unique dream of finding a machine with sufficient capacity to control by mathematical 

formulae the most complex situations. This is the same Timoteo who is happy in his weekend seminars to spread 

scientific knowledge, or sponsoring the summer courses with endless discussion sessions among graduates from different 

specialties, or creating, in cooperation with several universities, the first master’s degrees of Aerodynamics in 

our country. 

After so many publications and intellectual effort to solve so many practical applications, he has written a 

manual for students and lovers of aerodynamics. He should start with that peculiar phrase of the French Revolution: to 

all men, to all nations; so generous and global is his work and dedication. 

I am proud to declare him friendship and utmost consideration and I am moved to feel his permanent affection. 

Daniel Gozalbo Bellés 

(Mathematics Professor. Mayor of Castelló de la Plana 87-91) 

PREFACE-2 

Scalabroni: Engineers do not have dreams, we have ideas… 

This is effectively so; it is true that some ideas may seem unrealistic or difficult to perform but, as Julio Verne 

said, what some people can imagine, others will be able to make it… 

Only inept and stupid people copy things that don’t understand. 

10


BIOGRAPHIES OF THE AUTHORS 

ENRIQUE HÉCTOR SCALABRONI: 

His wide experience in the racing world says it all: Ladislao Haida Competition in Argentina, Avante – Formula 

Renault Argentina, Argentine official Renault team, Dallara automobili in Italia for four years (development of Formula 

3 and others, as well as the design of his wind tunnel), Ferrari F1 with Alain Prost, Williams with Patrick Head 

and Frank Williams, Lotus F1, Peugeot Sport in Sport Prototipos (Paris, France), Ikuzawa F1 and Maxim Conceptual 

Engineering (England), Asiatech Motors of F1 (Paris, France e England), Chief and owner of the GP2 - BCN Competition 

and Motorsport SL team (Barcelona, Spain). 

TIMOTEO BRIET BLANES: 

He has a Mathematics Degree and a Doctoral Degree in Industrial Engineering and is a PASSIONATE about the 

racing world. He has worked in GP2 and F3 and has been involved in countless projects of design and cars optimization 

(single-seater cars for race tracks, rally cars, sports cars, private cars). He has also been involved in racing motorcycle 

optimization (125 cc of Aprilia – 2009), design of long distance coaches and low-power Tata Motors. He belongs 

to an investigation group and has contributed to the development of the aero-post-rig theory; Lap Time, Navier 

Stokes equations, wind tunnel design, etc. He is teacher of Racing Engineering Masters in Spain, South America and 

Le Mans (France), etc… Currently, he works as coordinator of the Racing Engineering Master at the Nebrija University 

in Madrid. 

IGNACIO SUÁREZ MARCELO: 

Ignacio graduated as Doctor of Industrial Engineering by the University of Extremadura and specializes in Systems, 

Automatic, Electronic and Control Engineering. He has worked as a design engineer in built-in electronic systems 

based on microcontrollers. Currently, he works as a Professor at the Electric, Electronic and Automatic Engineering 

at the College of Industrial Engineering of Badajoz, where he teaches several subjects at the Systems and Automatic 

Engineering area. His investigation focuses on the control of autonomous vehicles, mobile robots, smart devices, 

control of CNC machines electronics and optimization of racing cars suspensions. He is also specialist in aero post 

rig. 

11


NOTES 

--Adrian Campos Junior (F3 driver, GT’s, Indy Cars, DTM): as a professional driver with experience from urban to 

oval tracks and with cars from Formula 3 to DTM, I totally recommend this book because Aerodynamics is the most 

important part of all kind of racing tracks and cars due to the high velocities they reach. I think that every enthusiastic 

about car racing should know the contents of this book in order to know and enjoy a lot more this wonderful sport. 

--BorjaVeiga(GT’s driver and test pilot): I have always been passionate about technical books, in fact, engineering is 

my failed vocation. I have studied and read everything I could, I have absorbed everything that engineers like Timoteo 

and Enrique have written and told. If it wasn’t for the knowledge they have given me, I would never have been able to 

drive and understand the racing car as I do now. From my point of view, drivers should read and try to understand 

treasures like this book and other books that our engineers give us. I assure you that a technical base would make your 

times lower. From my point of view, not reading these books, not knowing why all happens, leads you to errors and 

conjectures and to guessing the pilot factor of the equation in the moment that you have to set up your vehicle. This 

ceases to be what it should, at the time of the free workouts or testing days, a sensor of the car, the most important! 

Nevertheless, if you don’t understand what happens, if you don’t understand or know the behavior of the car, your 

contribution is poor and may even be useless, depending on the continuous and regular that you are. 

Consequently, it is an honor to know that friends like them continue working with the same excitement as 

always and helping me to understand a little better my passion, showing me the secrets and teaching me that the wonderful 

and glamorous world of car racing has also a wonderful part of calm and study of precision and knowledge, that 

leads us to grow and understand.In short, we can be better because of the tireless work of people like Timoteo, Enrique 

and Nacho, and with books like this. 

--Germán Sánchez Flor(F3 driver): I would like to congratulate Timoteo for this book dedicated to the study 

of racing aerodynamics. As a driver, I can say that it is a great progress for the development and evolution of the cars 

we usually drive, and as a future mechanical engineer, I can say that it is a great support for the students who finish 

our degree and want to specialize a little more and focus our knowledge to the competition. Hugs, Germán Sánchez. 

--Lucas Guerrero (GT’s driver): I met Timoteo when he cooperated with our team, GTA MOTOR COM- 

PETICIÓN, in the development of our cars aerodynamics. Since then, I walk in his footsteps and also those of 

www.tecnicaf1.es since its creation. They work in a still widely unknown field for the large majority of people, but I 

can give you an example to see the importance of it: RED BULL F1 and Mr. Adrian Newey are able to mark a difference 

with the rest thanks to new ways of taking advantage of single seater aerodynamics in order to be faster than the 

rest of the drivers. 

--Virutas de Goma – Zapico (Journalist – Humorist): A book like this was necessary because until now, 

there was nothing like that. The effort of Tim, Enrique and Nacho fills a gap which was empty. This gap is necessary 

for fans and supporters, necessary in the paddock. They will gobble this book, because without a literary precedent in 

this field, it will become a clear reference point. I wish that there were more people like them. Knowledge would be 

nearer for everybody. 

12


INDEX 

(Complet) 

Introduction 

Air and its context 

Principles, Properties and Consequences or Efforts 

Forces and moments 

Ailerons 

Ground and Diffuser 

Refrigeration 

Pressure center 

Aero – Map 

Flanges, suction intakes, Air Box, Trumpets and Exhausts 

Wind Tunnels 

CFD / Dynamic analysis of aerodynamics; Aero – Suspension combination 

Examples of racing implanted systems: F1, etc…. 

Air Dynamics 

Nomenclature 

Design of the dream car 

Post Rig analysis 

Aerodynamics / Suspension: dynamic analysis: Aero Post Rig analysis 

13


CHAPTER 1: INTRODUCTION 

This book fulfils a number of important determinants: 

All the sections are related. 

There isn’t an excessive mathematical preciseness; it would bring a lot of useless work. 

We speak of application and real examples. 

It is a book of practical aerodynamics, not theoretical; it isn’t a book of CFD. 

There isn’t useless information in it. 

Writing more and more equations or mathematical elaborations doesn’t mean that the knowledge of the author is 

wider. 

We hope that the experience of reading this book is nice and educational. That is the main target. 

As we go forward in investigations inventing new technical procedures, we will publish chapter updates in order 

to obtain a complete book from all points of view; the same will apply every year to the technical novelties of each 

season. These novelties will be included in the pertinent chapter. 

The target is to form an absolutely complete book related to the Technical Competition, particularly to Aerodynamics. 

In the same sense, practical examples and exercises notebooks about real cars will be edited. 

14


CHAPTER 2: AIR AND ITS CONTEXT 

2.1. DENSITY / PRESSURE 

The density of a group of particles is defined as the mass of the group of particles per unit volume. In other 

words, that is the amount of particles mass that we can collect with a given unit container. When more particles fit 

in the container, the higher the density of the group will be. 

Mathematically, we can express it in the following way: 

“m” is the mass of the group and “V” is the total volume; the units density, in the S.I., are Kg / m 3 . 

In fact, the molecules of the air cannot be over than a certain distance nor closer than a certain distance. Both limits 

mark out the compressibility of the air. 

In aerodynamic terms, the higher is the density of the air that the car faces, the higher the downforce will be. The 

drag will be higher as well. In order to increase the air density, we can do as follows: 

* Increasing the total pressure. 

* Reducing the temperature. 

Calculating the air density is not easy. We use indirect methods based in other parameters variations to know 

the variation of the air density. These expressions are called equations of state. To do this, we also need a “base” air 

density in order to know its variations. Consequently, we need the standard atmosphere definition in order to determine 

its values: 

We can rely on the following table in order to know the “standard” values: 

15


The use of this method of atmosphere is often used to exchange aerodynamic information without needing to know the 

density with which the trial has been made.The trial is supposed to have been made at a standard height of 0 meters 

above the sea level. Later, we will see more things about it. 

The pressure is another important parameter in all aerodynamic studies and depends on the already described 

density. 

There are three kinds of pressure: 

* Atmospheric pressure. 

* Relative pressure. 

* Absolute pressure (the addition of the atmospheric and relative pressure). 

The atmospheric pressure is the pressure exerted by the air on the Earth. The relative pressure is the pressure 

which is there, without considering the atmospheric pressure and its variations; it depends on the dynamics of the 

point. 

The atmospheric pressure at a point coincides numerically with the weight of a static lift of air of straight unit 

section which spreads from that point to the top limit of the atmosphere. 

The air density decreases as height increases. That’s why you cannot calculate that weight at least you are 

able to express the variation of the density of the “p” air according to the height “z” or to the pressure “p”. Therefore, 

it is not easy to make an accurate calculation of the atmospheric pressure on a point of earth’s surface. On the contrary, 

it is very difficult to measure it, at least with some accuracy, because both the temperature and the air pressure are 

continuously varying. We will discuss these interrelated variations in the section of “State equations”. 

In many studies, the air density is supposed to be constant and, therefore, incomprehensible (when air pressure 

increases, the molecules are closer per unit volume and, therefore, the density increases). This is absolutely false: 

there is no fluid, air or not, that has a constant density. For speeds under 400 km/h (…Mach < 0.3), air density doesn’t 

change a lot (but it changes). All fluids are more or less compressible, but they are. The fact of assuming that the density 

is constant, simplifies some calculation processes that, otherwise, would be very laborious, complicated and especially 

long. Supposing that the density is constant for speeds under 400 km/h, “always” means a mistake, but it is an 

affordable and small mistake. Furthermore, we can know it. 

Given a group of fluid particles, we know that each of them can only move within a sphere of a given radius: 

a particle can be neither further nor closer of a certain distance. Depending on the magnitude of these distances, we 

will obtain variously compressible fluids. 

Everybody knows the game called Newton’s cradle: 

16


The ball in motion collides with the row and makes the last ball move indefinitely. The row of balls transmits 

the movement from the start to the end, from the first to the last ball, making a good example of the conservation of 

energy and movement quantity. This is due to the rigidity of the balls, but it would be the same if they weren’t rigid or 

solid, as long as the deformations were not permanent and if there weren’t hysteresis phenomena. That is, when the 

balls of the pendulum were perfectly elastic. The sound or vibration is “instantly” transmitted over a piece of metal, 

due to the compactness of the material. 

Talking about constant density implies a high power of abstraction. If we put some billiard balls together inside 

the triangle and try to move them, we won’t be able. However, if the balls are tennis balls, we will be able… 

When we start a game of pool, we hit the white ball towards the first ball. When this ball collides, “all” the 

balls are ejected. This is due to the impact transmission towards “all the balls”. 

Similarly, we can think of a stone squeeze: we receive the same force we apply because the stone molecules 

transmit it. 

Let’sthink of a fluid element or a body submerged in a fluid. Let’s suppose that we push a portion of fluid. 

We will obtain the same force in every portion of the fluid. For this reason, the pressure of all the sides of the body is 

exactly the same. This is why without gravity, a body is in balance when is submerged. Let’s analyze and quantify this 

fact. The distribution of the forces which act on a submerged prism is: 

17


“A” and “b” are the components of a force (“F”), which is applied to the largest surface of the drawn prism. 

These components are determined by: 

The additions of the forces (components), which act on the prism, are as follows: 

We can write the areas of the prism as follows: 

This helps us to reach the following relation: 

The pressures are the same on all the faces of the prism. This determines the balance of "internal" forces on any 

part of the fluid or immersed object. 

18


Another think very important: if the gap space between the molecules is very small, the vibration transmission 

is faster; “M” Mach number: 

V 

M 

c 

“c” es the sound velocity in the context. 

c RT 

Cp 

 

Cv 

“R” is de gas constant and “T” the temperature. “C p ” and “c v ” are the specific heat with constant 

pressure and constant volume. 

Also: 

c 

dP 

 

d 

E 

 

In water for example: E = 2.15 10 9 N/m 2 with a density = 999.8 Kg/m 3 

In water: c=2.06 10 9 / 99.8 = 1435.4 m/s sound speed with 0º Celsius. 

In solids: 

Concret: 3200 – 3600 m/s 

Granite: 5950 m/s 

Diamont: 12000 m/s 

19


Now, let’s analyze the buoyancy phenomenon. 

It seems a truism but, why does a body float? Archimedes’ principle explains that if the weight of the displaced 

fluid is bigger than the weight of the body, this body will float. 

Let’s think of an immersed body. This body weighs less (the weight in picture 2 is less than in picture 1): 

This is because the fluid around or in contact with the ball transmits a force, the vertical component of which 

is equal to the weight of the dislodged fluid. This fact makes the body weigh less. 

Let’s think of the same experiment in absence of gravity: neither the ball, nor the water molecules would 

weigh and, therefore, the ball wouldn’t weigh. 

If we inflated ourselves, we would be able to float in the air: 

20


How much should we inflate ourselves to be able to float in the air? 

When asking how much should we inflated ourselves, what we are really asking is how much volume should 

we occupy, given our weight, to equalize or reduce the density of the fluid in which we are immersed? 

Given the density of a person and the air density at sea level: 

The “V” volume that we must reach to float is "x" times the initial volume of a human person, which is 

around 0.07 m 3 . If the mass of the person is 80 kg, let's see: 

In other words, we have to become an approximately 66.000 liters ball!!! 

We can see another very illustrative effect of the importance of the density and its existence: 

Let’s think of a submerged pendulum. We make it swing. 

We will be able to see that the pendulum will stop oscillating almost immediately. This is due to the opposition of the 

water molecules which act on it. In fact, the more density the fluid has (less compressibility), the less time the initial 

oscillation will take to stop. 

Now, let’s think of two identical pendulums immersed in a fluid and with opposed oscillations. 

21


After a short time, both pendulums will oscillate in the same direction and with the same frequency!!! 

Why does this fact happen? 

Because the density of the fluid, because its variations and the forces transmission trough the molecules. On the 

moon, this wouldn’t happen, due to the air absence. 

Once again, we can appreciate the laziness of the nature to the changes… 

Some final considerations about the density: 

- The higher the density, the higher the downforce which is produced by the vehicle. 

- The higher the density, the better the motor works (more molecules by unit volume which goes into the engine 

and, therefore, more useful power). 

- The higher the density, the higher the drag which is produced by the engine. 

- The lower the temperature, the higher the density will be. 

2.2. TEMPERATURE 

It is a very important variable from an aerodynamic point of view. In fact, the most important thing is that its 

variation makes, for example, the density and pressure change. From all the temperature measurement units, two of 

them are the most important: 

Kelvin (K) and Celsius degrees (ºC); the relation among both measurements is: 

The temperature, according to the kinetic theory of gases, is a function of the average kinetic energy of the 

molecules which constitute it. In this way, we can say that, as a first approximation (ideal gas), the temperature is determined 

by the following expression: 

22


“T” is the temperature; “K B ” is the Boltzmann’s constant, and is the average kinetic energy. 

One of the most important consequences which the temperature has on the air is the fact that the lower the 

temperature, the fewer molecules per unit volume there are. This is a damaging fact to the downforce (it makes the 

downforce be lower) and to the functioning and performance of the engine. The higher temperature (red), the more 

separate the molecules are: 

2.3. AIR STATE EQUATIONS 

All the variables of the air are interrelated. We know, by our experience, that if we climb a mountain or take a 

plane, the temperature and atmospheric pressure vary. In this section, we will study mathematic expressions and relations 

among the most significant variables in order to discover its variations depending on other variations. This expressions 

or relations are called “State Equations”. 

The most used state thermal equation is the “Clapeyron” equation, due to its simplicity and its good results. It 

has been obtained through the study of the “Amagat” curves for the ideal gases. If we choose any given gas and represent 

for different temperatures the function (“v” is the molar volume and “P” is the pressure), we can observe 

how, for all the temperatures, the curves meet each other in the same point when the pressure approaches zero. The 

same happens when we do the representation with different gases. This so interesting cut-off point on the X/Y axis has 

the value of 8,314 J/mol·K in the international system. Yes, it is the called “R” universal constant of ideal gases. 

An ideal gas is a gas whose particles haven’t got any potential energy. They only have kinetic energy. In other 

words, an ideal gas is a gas whose particles don’t interact with each other in a perceptible way. This is why the 

model of ideal gas is used in the cases in which the temperatures are relatively high (the potential energy is insignificant 

compared to the kinetic energy) or in those in which the density is low (the potential energy of the particles is 

very low). Fortunately, this happens in most cases. 

The state thermal equation of an ideal gas is determined by the following expression: 

“P” is the pressure, “T” is the temperature, “R” is the “universal constant of the ideal gases” (useful for all the 

gases) and “n” is the number of moles. 

Talking about ideal gases, we know that a gas is perfect when its specific heat is constant. 

The known Gay-Lussac or Boyle-Mariotte laws are deducible through the state thermal equation of ideal gases, 

depending on the variables which remain stable in the thermodynamic process. 

23


To simplify the expression and make it particular, we use: 

, where “m” is the mass, and 

“Rg” is the air constant (it is a constant for our application of low velocities, low pressures and low temperatures). 

Therefore, we can write the following expression: 

To obtain the variations of each of them, depending on the other variations, we derive the expression, obtaining: 

“Rg” (for the air) is: 287.03 J/kg·K. The three differentials belong to the possible variations of such variable. 

We can obtain really useful expressions through the state equations. For example, let’s think of two points at 

a different height in comparison to sea level. We can write the following: 

We know, by the basic equation that, being “g” the gravity acceleration: 

If we substitute, can write the following: 

If we integrate at both sides of the equation: 

Resolving: 

We can reach the following expression: 

Obtaining the pressure depending on the “y” height, and knowing the pressure at an “y 0 ” height… 

24


Let’s suppose another hypothesis. For example, the relation: 

We would obtain another state equation for the pressure and height. 

This procedure of supposing a hypothesis to make a useful expression is something very usual and necessary in 

many cases: we have to be able to deduce the correct expression, this expression which allows us to know what we 

want to know. For example, let’s suppose that we have to know an expression to know the area of a sphere. Firstly, we 

must decide what values or parameters will participate. In this case, we only choose the radius of the sphere. “A” is the 

searched area, “R” is the radius and “K” is a constant. We have to calculate “a”: 

Now, let’s make a dimensional analysis: 

Therefore, we have the expression and K= . 

Let’s see other example: 

Let’s suppose that we have to know the density. To do it, we can use one of the two following expressions. We 

will work with that expression which with we can work easier: 2 

There are a great number of state equations, such as the “Van der Waals” equation, the virial development or 

the “Berthelot” equation. Nevertheless, the state equation of ideal gases is enough to our action conditions. 

For the more skeptical people, we will use the called “Z” compressibility factor, which offers us a measurement 

of a really good approximation to the ideal gas. This variable is defined as: 

Therefore, when this variable is equal or very close to the unit, the gas behaves perfectly like an ideal gas. 

Let’s see some values of the “Z” compressibility factor for the air in an exaggerated level of acting: 

25


As we can see, the ideal gas model is away from realty when the temperatures go down and the pressures go up. Our 

chosen range is -23.15 ºC and 5 bars, when the compressibility factor is 0.9957. This is not a common situation. We 

cannot find this work conditions in any track. As we have seen, even in extreme conditions of temperature and pressure 

with which we wouldn’t work, the ideal gas model is still very useful. 

Now, let’s see some examples of the use of the “Clapeyron state equation”. The following, is a typical case in 

the racing world: 

We have aerodynamic data taken at different times, on the track or in the wind tunnel. 

We need to standardize them to 250 km/h in order to compare them well. For example, we can apply it to a 

GP2 single-seater car category (downforce data in kilogrames and velocity in km/h). 

The downforce is determined by the expression: 

“ ” is the air density, is the downforce coefficient and “A” is the frontal area of the car. 

We want to obtain the downforce front with a different velocity but with identical conditions. The quotient 

between the known downforce and that which we want to discover is determined by: 

If we resolve the equation we have: 

The subscript “2” indicates the velocity, in this case, 250 km/h. The subscript “1” indicates the velocity in the 

table above. Therefore, to correct, for example, the first velocity, we calculate: 

26


As we have said, we have supposed that all the values are obtained with the same density. In case that we 

have a different temperature and pressure (different density), we would use the state thermal equation to find the density 

and do again the aerodynamic charges quotient. In other words: 

If we operate, we have: 

As we can see, the procedure is not complicated. 

Let`s see another typical case of the use of state equations: 

We know that the less unsprung mass we have, the better the car dynamics will be. For this reason, we can 

make the tire air weigh less, keeping a certain pressure. To do this, we use the studied expressions. We can create an 

Excel sheet in order to do some calculations. 

Let’s suppose that we want to inflate a tire and reach a certain pressure at a given temperature. 

These input data correspond to dry air. In this way, we obtain a result of: 

- Volume of air to be introduced. 

- Mass of air to be introduced into the tire. 

We can do it with other gases or even mixtures just changing, "the constant/s of the gas/es". In the case of Nitrogen: 

27


In this case: 

Furthermore, and as a culmination, we can also use the same created template in order to know how much 

gas we have to remove or introduce in the tire, in the following case: 

- Temperature has varied. 

- Pressure has varied and we want to keep it or reach another pressure. 

This is a typical case when a car stops for a revision of pressures. 

We can improve the calculation template as follows: 

The parameters with which we have to work are: 

- Internal volume of the tire. 

- Inflation pressure. 

- Temperature of the internal gas. 

- Mass of the internal gas. 

Calculating any of these values must be possible depending on the other three values; this would be the improvement 

and the goal of the new worksheet template. 

Let’s analyze the influence of the temperature variation in a tire. 

We have the variations of the pressure (bar) depending on the temperature: 

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The top two lines correspond to the frontal tires. As we can see, they always tend to heat up more. It is necessary to 

know these graphs for each tire with which we are working (the damping or rebound of the tire will change, as well as 

its diameter). 

2.4. VISCOSITY 

Viscosity is one of the most important variables that characterize the air. It is responsible for many of the 

phenomena and forces that take place in the car world. Its analysis or quantization is quite simple: 

Let’s suppose we have two plates. They are separated at an “h” distance. It is no air between the plates. Let’s 

suppose that we move one plate with respect to the other with a “U” velocity. 

29


“F” is the force we have to do in order to move the plates. This force is proportional to the “U” velocity and 

to the “A” area (the area on which we do the force). This force is inversely proportional to the “h” distance which separates 

the plates. In other words: 

“A” is the area of the plates. We can establish: 

We define the "μ" absolute or dynamic viscosity as the constant of proportionality: 

We define “kinematic viscosity” as (it is just useful for convenience, gathering two terms): 

Viscosity acts as a brake close to the surface, slowing the air molecules. We can see its effect in the following 

experiment: the air “drags” the cart with a certain force. 

30


We have to think of viscosity in a different way. Let’s see: 

You can write the expression 

in a different way. We can arrive at the following expression 

from the definition of velocity and using simple trigonometry: 

As we can see, the group of molecules has temporal properties of reaction. In other words: let’s suppose that a 

certain molecule moves on (for whatever reason) in a certain direction. The molecules around it will react to this 

change of position, changing its positions and velocities. This will cause a moment exchange, following the first 

moved molecule. The reaction time of the molecules responding to changes of other molecules is called viscosity: 

- The longer the reaction time, the higher the viscosity. 

We all have said phrases like “traffic in a big city is viscous”. This means that cars are "lazy" responding to 

the changes of the cars which are before them. This brings the slowing of all the cars in the city. 

If we manage to think and identify airflow with a “people” flow, we will be able to understand many things. 

An essential concept in vehicles aerodynamic is called “viscous plug”. It takes place in small cracks or openings 

such as the suction intake, but especially between the car underfloor and the pavement. Due to the viscosity 

among the air molecules, there is a moment (which depends on the velocity and air parameters) when a plug is created 

and the air cannot pass with a high velocity. At that time, the velocity increase is paralyzed despite the fact that the car 

is faster and faster. We will see this in the section of the diffuser and the ground effect. 

Viscosity is a property that varies with temperature. For example, gases viscosity is determined by the following 

expression: 

31


Depending on the kind of gas with which we are working, each parameter will have a different value. We can see the 

values in the table: 

In the case that the fluid is liquid, the values of the density and viscosity will be determined by: 

This is the expression for the “ 

” density: 

“ ” and “ ” are experimentally determined parameters. The expression for the water is the 

following: 

We show below the values of the parameters which are required for some substances: 

is the viscosity measured in kg/m/s, “T” is the temperature measured in , is the viscosity at 

20 ºC and “C” is a dimensionless parameter. The parameters and are experimentally determined for each kind 

of liquid. 

Water is an exception obtained by the following expression: 

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Where and 

2.5. THE ATMOSPHERE 

The atmosphere is a gaseous layer which is approximately10.000 km thick and is located around the Earth. 

It’s composed by different gases –principally nitrogen and oxygen- and solid and liquid particles in suspension which 

are attracted by the Earth’s gravity. All the weather and meteorological phenomena are produced in this layer. It regulates 

the energy input and output from the Earth. It’s the main way of heat transfer. 

The atmospheric pressure value is the same as the weight of a unitary air column from the point where we 

want to calculate the atmospheric pressure to the atmosphere upper limit. 

Due to the weight of the particles which form the atmosphere, the highest percentage of the atmospheric mass 

is located in the first kilometers. 50% of it is located under the 5 km, 66% is located under the 10 km and beyond the 

60 km only one thousandth of it is located. Therefore, as we can see, it is not a gaseous layer with constant density, 

but it is a layer whose density decreases when the height from ground increases. 

Taking a linear fall of the temperature in the atmosphere such 

is a good approximation for 

the first 11 km of the atmosphere, called Troposphere.Meanwhile, in the first 9 km of the Stratosphere, the temperature 

remains constant 

at -56.5 ° C, as we 

can see in the following 

figure: 

The temperature variation depending on the height for the whole atmosphere is shown in the following 

graphic: 

33


All the values we have seen depend on each other. This makes it necessary to determine a common and 

standard atmosphere to be able of unify and contrast experiments, tests, trials and calculations. This base atmosphere 

is called “Standard Atmosphere”. 

Surface values at sea level: 

Temperature: 15ºC (59ºF). 

Pressure: 760 mm o 29,92" of mercury column, equal to 1013,25 mb per cm². 

Density: 1,225 kg/ m³. 

Acceleration due to the gravity: 9,8 m/s². 

Speed of sound: 340,29 m/s. 

Thermal gradient of 1,98 ºC per each 1000 feet or 6,5 ºC per each 1000 m. 

A pressure drop of 1" per each 1000 feet, or 1 mb per each 9 meters, or 110 mb per each 1000 m. 

34


2.6. LAMINAR FLOW AND TURBULENT FLOW 

All of us know what laminar and turbulent mean, but hardly anyone knows its mathematical definition. 

“Laminar” sounds like “light” or “linear”. “Turbulent” sounds like “complex”. It is indeed thus. We say that 

the flow moves in a laminar way or it is somewhere, laminar, if the velocity field rotational is zero. If it isn’t, we say 

that it is a turbulent flow. In other words: 

The beginning of the turbulent layer or turbulent flow is something very important that determines the air 

aerodynamics. It is not easy to know this transition. 

We know that the higher the velocity, the more turbulent the flow, but it is complicated to know at what velocity 

the flow will be turbulent. The Reynolds number can indicate under some certain specific conditions, this step 

from laminar to turbulent flow. 

35


The Reynolds number is defined as: 

In the case of the cars, knowing the transition velocity is much more complicated. It is necessary to test by using 

CFD, wind tunnels or similar ones. 

There are two explanations of the conversion from laminar to turbulent flow: 

Shearing layer (stress layer): 

A shearing layer is an area of flow where the velocity gradients are high. In other words, the velocity varies in a 

very perceptible way, as we advance forward the normal direction or in a perpendicular way to the movement. 

-Within this flow, an infinitesimal perturbation is caused. This perturbation causes a light wave. 

This undulation causes: 

-The increase of the flow velocity on the convex zones (A, B’, C, D’). 

T-he decreaseof the velocity on the concave zones (A´, B, C´, D). 

-If we consider the stable flow, by applying the “Quantity of Movement Equation”, it is created a force, which 

increases the disturbances. In this way, the shearing layer becomes unstable and the original undulations become 

vortex or whirlwinds. 

In the real life, we can see these turbulences watching the sky: 

36


Considering the origin of turbulence in terms of small initial disturbances, one case where we can see and 

observe the creation of turbulences is the curtains of most rural houses. We all have seen this curtains which are 

placed on the door to prevent the entry of mosquitoes. If it’s windy, we will see that the curtain starts to ripple. Originally, 

the curtain doesn’t move, but with a slight alteration, the wave starts. 

In fact, this conception of the origin of the turbulence can create Jupiter’s cloud bands and its storms or whirlwinds. 

37


Later, we will study it in depth, but this is the main reason of the necessary precision in the limit layer definition, 

when we perform a CFD simulation!!! 

Viscosity: 

Let’s imagine a pedestrian who is being chased by another pedestrian. We suppose that the pursuer pedestrian 

has a certain reaction time in face of the changes of direction of the chased pedestrian. If that reaction time depends 

on limits or intervals, the pursued pedestrian’s trajectory may trace the following graphic with turbulence 

aspect: 

—> important: 

Are there a relation between the gap time of reaction (viscosity) and the mach number ???? 

I think yes……………………………. Thinking about that……………………………….. 

Therefore, depending on this reaction time, the turbulence will exist or not. 

Characteristics of turbulent flows: 

-- Irregularity:Any turbulence has a pattern of irregularity because at least apparently, is unpredictable. The fluctuations 

appearance of fluid-dynamic variables (velocity, pressure, temperature, concentration) with very different sizes 

and times (different scales), give the turbulence an irregular nature. 

-- Three-dimensionality: Any turbulence is three-dimensional. The lower the scale size, the more perceptible this fact 

will be. 

-- Diffusivity:The transport phenomena of mass, movement quantity and energy, are increased by the turbulence effect. 

The corresponding effect is analogous to molecular scales with the molecular transport. 

-- Dissipation: After the turbulent flow has been developed, the turbulence tends to be stable, being necessary an input 

of energy. This energy becomes a series of processes of fluid elements deformation. The absence of this energy 

input means that the turbulence is progressively smaller. 

Sir Horace Lamb (1849-1934), in an international tribute which was celebrated for his eightieth birthday in 

1929, said: “When I die, I hope I go to heaven. There, I hope being illuminated about the solution of two problems: 

quantum electrodynamics and turbulence. I’m very optimist about the first one…”. 

The first problem was solved by Richard P. Feynman (1918-1988) and because of that, he won the Nobel 

Prize in 1965. Feynman: “Turbulence is the last important unsolved problem of classical physics”. 

38


POWER UNIT: EXPLANATION 

Ingeniero Industrial, especialidades en Electrotecnia y en Organización de la Producción por 

la Escuela Superior de Ingenieros Industriales de Gijón. Doctor Ingeniero Industrial en Ingeniería 

de Fabricación por UNED. Coordinador del Área de Tecnología Eléctrica y del Área 

de Proyectos en la Escuela Politécnica de la Universidad Nebrija. Catorce años de experiencia 

docente en Máquinas Eléctricas y Teoría de Circuitos. Profesor de Vehículo Eléctrico. 

Experiencia investigadora en mejora de los procesos productivos, simulación de procesos de 

fabricación mediante elementos finitos y en modelización de vehículos eléctricos. 

The new Formula 1 season, and so it’ll be up to 2019, it’s polarized by the replacement of the V8 engines by new turbo-hybrid 

V6 electronically advanced that they should be called 'Power Units' or powerplants. The internal combustion 

engine (ICE) is less potent, which will be necessary to supplement it with an alternative system (ERS) that will let 

it has more pulling power. Also it’ll reduce fuel consumption, because now it’s limited by law to 100kg / h (art.5.1.4). 

By Timoteo Briet (@tecnicaf1) and Roberto Alvarez 

Translated by Jorge Tornay 

Article 5.1.5 regulations limited fuel injection by applying a formula where below 

10,500 rpm the fuel flow injected can’t exceed the value Q(kg/h)=0.009 N (rpm)+5.5 . This limits the power at low 

revs being essential an additional engine, which will be an electric motor. 

Moreover, the V6 thermal efficiency is around 40%, so there is a 60% energy loss that can try to recover. The 

ERS system will try to take this energy turning into electricity to power the electric traction motor. 

The ERS (Energy Recovery System) will have two combined systems, more power, and longer utilization. Last 

season, the KERS (Kinetic Energy Recovery System) gave extra power of 60 kW for 6.67 seconds per lap. This 

season the new ERS system will push for 33.3 seconds and the maximum boost changes from 120 kW, equivalent 

to about 163 horse power in order to compensate for the power loss caused by the reduction motor. 

39


The ERS system consists of three main modules: two systems MGU(Motor Generator Unit), called MGU-H (Motor 

Generator Unit - Heat) and MGU-K (Motor Generator Unit - Kinetic). These units will be responsible for recovering 

the energy and convert it into electricity for storage in the ERS third module, the energy store. This will require much 

prior calculation and dimensioning but also take added a strong implementation of electronic power and control systems. 

In this figure you can see the ERS components in the new Renault motor (Renault Energy F1). 

And then you can see the layout in the Mercedes engine. 

MGU 

The MGU is an electric machine which acts as a motor-generator. It’s very important to emphasize the concept of 

duality of operation. When operating as an engine, the MGU converts electrical energy into mechanical energy. 

When operating as a generator, the MGU converts mechanical energy into electrical energy. A Formula 1 contains 

two units of energy recovery MGU; the MGU-H (for recovering energy from the exhaust gas turbocharger) and 

MGU-K (for recovering the kinetic energy during braking). 

Now we’re going to explain the units: 

MGU-K 

It’s the system used previously as KERS and its performance has increased significantly. It is connected to the 

crankshaft of the internal combustion engine and is able to recover or supply power (limited to 120 kW or 160HP according 

to the rules). At the time of braking, when the driver steps on the brake, the MGU-K acts as engine braking to 

slow down (reducing the heat dissipated in the brakes) and recovers a portion of the kinetic energy to convert into 

electricity. Then, when the driver requires more power than can provide ICE, at the time of acceleration, MGU-K acts 

as a mechanically propelled vehicle. 

MGU-H 

The MGU-H is the heat recovery unit and it’s connected to the turbocharger. Its purpose is twofold: 

40


By acting as a generator, the power absorbed from the turbine shaft to recover the thermal energy of the 

exhaust gases. Electrical energy can go to MGU-K or battery to store and take it later. 

The MGU-H engine is also used to control the speed mode of the turbocharger and match it to the air requirement 

of the engine (for example, to lower the speed instead of the wastegate valve or speed in order to 

compensate for the turbo -lag). The turbo-lag is an important concept; it’s the time from the accelerator pedal 

until it becomes effective pressure increase in the feed. In this operation the MGU-H used to operate the battery 

power. 

The MGU-H is an electrical machine that in electric motor mode allows controlling the turbo, accelerate and 

stop it on demand, exerting pressure blowing generated as needed. When acting as a generator will use braking 

Its purpose to work as a motor is to control the turbo, so when the car turn at low speed increases the pressure 

in the turbo and improve power immediately, eliminating the delay in the turbocharger response and allowing 

the engine to have a more progressive response for a higher speed. 

41


ENERGY STORAGE SYSTEM 

What is usually understood as battery or storage unit is a complex system composed of several elements: The 

whole-cell battery, inverter or converter and the cooling system. As you can see in this Renault F1 scheme, we can 

see that the MGU-H and MGU-K don’t supply power directly to the battery, but some "converters" which 

convert power parameters allowing its entry into the battery. The MGU generators are three-phase alternating 

current while the battery charges in direct current, then an electronic system that converts energy and suits for 

entry into the battery is needed. Usually this type of elements are called investors, and are key to energy management 

as discussed below. 

The investor will also functionality to convert battery power DC to AC three-phase when the MGU-H and MGU- 

K work as motors to drive the turbo or aid traction respectively. The speed and torque to provide these units in 

operation as a motor are controlled by the voltage and frequency at its terminals, and the converter which provides 

adequate values. 

Batteries for cars by 2014 have a minimum weight of 20kg and up to 25kg by rules, being able to generate 

160 hp. The batteries for electrical energy storage are formed by cells that can be associated with each other for 

more or less voltage, current and power. The dilemma is, first select the type of technology and on the other 

the number of cells to use. The two key factors in defining the batteries are the power density (specific power or 

Watts per Kilogram) and energy density (specific density or Watt-hour per Kilogram). The optimal combination 

of these two factors is the key to the selection of cell technology, and the number of them. 

The teams are very jealous about revealing their know-how, but it seems clear that the battery technology, at least 

for now, would prefer the use of Lithium Ion with Manganese or iron phosphate (LFP), leaving open innovation 

with Lithium Polymer and Lithium Air. It is the most important and fastest evolving technological challenge. 

IN RACE 

How does this affect the race? The new MGU-K, which replaces the KERS allows use 4MJ energy per lap 

(art. 1.27 regulations). These 4MJ can get the storage system (batteries) or retrieving himself. However, the legislation 

prevents recover 2MJ per lap with MGU-K (art. 1.25). So the car has to be attached another system 

(MGU-H), which can recover energy without limit (art. 1.26) and storing that energy in the battery system or 

providing them directly to MGU-K in order to provide in each lap full 4MJ. With this extra power the pilot will 

have additional pull of 160HP for 33 seconds. The use of different components of the ERS is summarized in this 

figure: 

42


The benefits are clear, but what problems can have this technology? 

The MGU unit generates more heat than the 2013 KERS, only this phenomenon can generate a lot of problems 

and can be a source of failure and significantly affect the operation of the battery. Therefore, the focus 

should be on the cooling system and its reliability. If KERS broke in 2013’s championship the car was left 

with three quarters of its power and the lost lap time was acceptable (about 0.3 to 1 seconds a lap depending on 

the circuit). However a problem of breakdown in unit MGU cause more serious problems, since not only 

affect in terms of power decreased against your competitors, but could also cause turbo-lag (if the error affected 

the MGU-H). 

Another important factor to consider is the way we can reduce the size and weight of batteries. For example, 

if you come to a slow curve, the car slows and activates the MGU-K begins to produce electricity. It could store it 

in batteries, but could also be used directly to actuate the turbo so that at the exit of the curve traction with the 

turbo activated by the MSU-H. That is, it is not stored, the electricity generated is used directly. The same is true 

in reverse, straight the MGU-H generates electricity that can be sent to the other motor-generator unit (MGU-K) 

to increase the car’s speed at almost any time of the lap without the need for store large amounts of electricity. 

Electronic control is also very important. Having a powerful MGU-K the car has a system that is able to slow 

the car and helps conventional brakes. Normally they act both at the same time a greater or lesser extent but it is 

possible that, under certain conditions, the MGU-K does not act. For example a circuit with many curves as Monaco, 

there aren’t many areas where you can use the ERS power and there are many where you can use the brakes 

to recharge. Electronic control decides how to brake, if more dissipative (charging more conventional brake) or 

more regenerative (using the MGU-K as engine braking). 

To solve this problem the electronic brake control (Brake by Wire) mounted in the rear axle and trying to improve 

the brakes performance by measuring the pressure exerted by the driver on the brake pedal and calculates how to 

We shouldn’t forget the electromagnetic effects arising from energy storage and its effects on data acquisition 

career. Magnetic shielding and reliability are also a factor to consider. 

43


FAN CARS: WHAT´S IT ALL ABOUT 

About the author 

This project was performed in the CFD and Race car aerodynamics and CFD course imparted 

by TecnicaF1 (Timoteo Briet). The author is Josep Mª Carbonell, aeronautical student at 

UPC in Terrassa (Barcelona), and a race cars enthusiast. That’s the reason behind this project, 

the objective was to put all this knowledge into designing a race winning car concept. 

Contact Details 

Mail: jmcarbonelloyonarte@gmail.com 

Linkedin: Josep M Carbonell Oyonarte 

Aerodynamic study of the implementation of a fan to a racing car 

44


1- Introduction 

In the world of motorsport, there have been a lot of developments benefiting maximum speed, resistance and speed 

cornering. This document deals with the later. Generally speaking there are 2 main ways to increase cornering 

speed: 

· Increasing mechanical grip through improvements of shock absorbers, springs, anti-roll bars, camber and castor 

angles, etc. 

· Increase the downforce of the car through aerodynamic work with spoilers, wings, air flow around and under 

the car, etc. 

Since mid-60’s, the most popular way to obtain downforce have been the implementation and fine tuning of aileron, 

flaps and spoilers but there have been some others paths to create downforce from the air. One of these ways is creating 

a low pressure area under the car, as a high pressure are always try to move towards a low pressure area 

the car is effectively sucked towards the ground. 

The basic idea is to accelerate the air under the car, the first step is adding a rear diffuser which accelerates the air 

exiting the rear. Also, we have to ensure that as little air as possible enters the bottom of the car through the sides 

and that there is the least possible air under the car. There are two ways to make that: 

· Putting skirts to the floor. 

· Creating an aerodynamic wall along the car. 

In 1970 a new concept was born. Jim Hall and his team created a new car, the Chaparral 2J. it was a pioneer of one 

of the most incredible inventions and pieces of lateral thinking in racing history: placing a fan at the rear of the car 

in order to suck the air from under the car increasing the pressure differences and effectively sucking the car to the 

tarmac. This development was quickly banned in the Can-Am category, due to the large performance advantage of 

this concept. 

Eight years after, Gordon Murray and his Brabham team, run by Bernie Ecclestone, resurrected this concept in Formula 

1 with the BT46B, famously remembered as the “Fan car”. The story of this car was the same than Chaparral, 

it was banned after the first race because of the overwhelming dominance. 

45


46


2- Reviewing the concept 

After so many years without any advances on this concept, a new car has been developed. This car is different, because 

it’s a virtual car, the Red Bull X1. The designer, Adrian Newey, used all the advances and concepts possible 

to improve the car, even if they aren’t allowed in any category of motorsport. 

Our objective was to study a car similar to Red Bull X1, and quantify the Fan Effect and it’s on the performance of 

the car. 

This is the car used: 

And this is the fan placed behind: 

47


As we can see, the car has wheel fairings and a close cockpit, two improvements in terms of drag reduction banned 

in Formula 1. Also, it counts with ground effect, because it is a so-called “wing car”. This design allows increasing 

total downforce, and combined with the fan, the magnitude of downforce can be stunning. 

The definitive improvement of the car is its skirts, closing the area for a better suction. 

3- Targets of the study 

The main targets of the study are as follows: 

Minimum fan speed in order to improve downforce. 

Correlation between downforce and fan speed. 

Correlation between drag and fan speed. 

We are not looking for quantitative results, because the resources able for this project don’t permit more precision on 

the data resulted, but we are able to obtain a good qualitative results of the targets of this study. 

4- Meshing 

We have configured a polyhedral mesh and a boundary layer around the car to obtain more precisely the downforce 

and the drag induced on the body. Before configure the boundary layer, we calculate first layer thickness based on 

the air speed and the y+ desired. Also, we added a block mesh on the entire region around the bottom of the car and 

the diffuser. This block mesh has smaller mesh size than the rest of the volume and gives us more control and precision 

around this area, the most important of the car in this study. 

5- Simulations and results 

The first step was to set up the basic parameters: 

Air velocity: 220 Km/h 

Rolling ground and wheels to make the simulation and its results more realistic. 

The next step was to identify the minimum fan speed which increases downforce. After several simulations at different 

fan speeds, the minimum speed was determined as 25000 rpm. Under this speed, the fan decelerates air passing 

under the car and downforce falls. 

This is the pressure distribution over the car: 

48


And this is the pressure distribution under the car: 

49


We can see the depression created by the diffuser and the fan, which starts just at the front skirt of the car. This is 

the reason of the large improvement in terms of downforce. 

These are the streamlines over the car, and we can see how the air interacts with the car: 

Another interesting visualization is the velocity vectors on side plane for a future upgrade of the aerodynamic design 

of the car: 

50


After this previous study, we proceeded to compare the drag and downforce of different fan speeds and, of course, 

the base scenario where there is no fan. 

5.1- Downforce 

When simulations had been made, we analyze the outcomes of downforce of each speed, and compared them with 

the downforce of the car without fan as we were looking the improvement made by using a fan. 

We can see now the effects of using a fan in terms of downforce improvement. We can say that the magnitude of 

improvement is remarkable in terms of speed through the corners, but before definitive conclusions we must analyze 

what is the effect on the maximum speed, since a large increase in drag would penalize us much on the straights. 

5.2- Drag 

Here we analyze the results of the drag in each fan speed. We did the same as for the downforce, so we compared 

the drag with fan and without it. 

51


The study demonstrated an increase proportional to the fan speed, an increase in downforce always causes more 

drag. Maybe the most important fact is that the increase in drag is very small compared with the gains in downforce. 

6- Conclusions 

The results show the very interesting use of a fan, it produces a large gain in downforce but with only a small increase 

in drag. The use of the fan is recommended in all circuits except very bumpy circuits where large changes in 

distance of the floor to the ground could suddenly produce an alarming loss of downforce, resulting in a potentially 

uncontrollable and dangerous car. Moreover, the use of ground effect needs stiffer suspensions as the distance of the 

floor to the ground has to be the controlled as much as possible. This means a more difficult work for the driver. 

One of the possible ways to improve this concept is to design a system which allows transmitting the best fan velocity, 

or the right grade of blades, for each condition and position of the car. The next step is to stop the fan in the 

straights because its effect is detrimental for the tires and it harms maximum speed. 

As a conclusion, it’s clear that, with some investment and fine tuning of the system, this concept can be very worthwhile. 

52


AERO POST RIG ANALISYS 

1. Motivation: 

The performance of an F1 race car is greatly influenced by its aerodynamics. Race teams try to improve 

the vehicle performance by aiming for more levels of downforce. A huge amount of time is spent in wind tunnel 

and track testing. Typical wind tunnel testing are carried out in steady aerodynamic conditions and with car static 

configurations. However, the ride heights of a car are continuously changing in a race track because of 

many factors. These are, for example, the roughness and undulations of the track, braking, accelerations, direction 

changes, aerodynamic load variations due to varying air speed and others. These factors may induce movements 

on suspensions components (sprung and unsprung masses) at different frequencies and may cause aerodynamic 

fluctuations that vary tires grip. When the frequency of the movement of a race car is high enough the steady 

aerodynamic condition and the car static configurations are not fulfilled. Then, transient effects appear and the dynamics 

of the system changes. Heave, pitch and roll transient movements of the sprung mass affect both downforce 

and centre of pressure position. The suspension system have to cope with them, but in order for the suspension to 

be effective, unsteady aerodynamics must be considered. 

The main objective is to model the effects of unsteady aerodynamics with the aim of optimizing the suspension 

performance, improving tire grip and finally reducing lap times. 

2. Methodology: 

Traditionally, optimization 

of race car suspensions has been 

researched by using the well known 

quarter car model. Despite of its good 

results, it is no able to provide clues 

on the pitch behavior. A better approach 

to study the ride performance 

of a race car is by means of the half 

car model depicted in Figure 1. This 

model introduces some parameters 

that permit to simulate the attitude 

of the car (pitch, heave, ride heights) 

as well as the tires grip. It gives a 

more realistic approximation to the 

real performance of a race car, however 

it lacks in aerodynamics, extremely important in racing. 

The introduction of the aerodynamics in the half car model can not be in the form of an aeromap, because 

this is obtained in steady conditions and it does not reflect aero-transient effects. A good solution is to introduce 

some transfer functions that take into account those effects. Figure 2 illustrates this concept. 

53


For the sake of simplicity, let us assume there is no roll movement. Any change in the attitude of the car 

(for example, in ride height, Zcg, or pitch angle, θp), due to road undulations or braking or accelerating maneuvers, 

may cause a fluctuation on the car aerodynamics by changing its downforce (Fz), or shifting the center of pressure 

(represented in Figure 3 by an aero-torque acting around the gravity center of the sprung mass, Tp). The way 

the attitude changes affects both the downforce and aero-torque depends on the frequency of the car movements. 

Modeling these effects is the task proposed here. 

The objective is to find different transfer functions for modeling the unsteady aerodynamics. The input 

signals are the pitch angle (θp) and the gravity center ride height (Zcg), but they may also be front and rear ride 

heights (RHf and RHr). The outputs are the downforce (Fz) and the aero-torque (Tp). 

54


It is important to pay attention in the first place to those transfer functions that affect the most to the behavior 

of the race car. For example, the influence of a change in pitch angle may be greater in the aero-torque than 

in the downforce, or a change in the heave position may be more important in the downforce than in the aerotorque. 

However, all the possibilities must be explored. 

Due to the non-linear nature of the aerodynamics, the transfer functions must be computed for different 

configurations, i.e. for several air speeds or ride heights, since in a same track different car configurations can be 

given. 

There are two ways of computing the aerodynamic transfer functions: in the wind tunnel and in a CFD 

simulation program. In both cases, frequency identification methods may be used for estimating the transfer functions. 

Then, these transfer functions should be included in the car model and a better optimization of the suspension 

parameters could be obtained. 

For the wind tunnel tests, a Continuous Motion System (CMS) with a high speed data acquisition 

system is required. This must have a high bandwidth servo-controller platform in order to provide high frequency 

movements to the scale model. The system must be equipped with sensors for measuring downforce, aero-torque 

(or front and rear downforces), pitch angles and ride heights. 

For the simulation tests, a CFD computer with the car model is required. The CFD software must 

have the ability of simulating a moving model. 

For both kind of tests (wind tunnel and CFD), frequency identification techniques may be applied. 

For example, the pitch angle of the model can be varied according to a chirp signal (used as input) and the downforce 

and aero-torque must be recorded (together with the input signal) into a file. A similar test can be implemented 

using the gravity center position as an input and then recording all the magnitudes into a file. A 

MATLAB script can compute the Fourier Transformation of all the magnitudes and then several transfer function 

can be obtained. 

3. How to use the aerodynamic transfer functions: 

Once the transfer functions have been computed, they can be used in different ways. One method is to 

introduce them in a virtual post rig simulation 

package. Optimization of the 

suspension setups can be carried 

out by using novel frequency response 

methods that compute several. 

Finally, it´s possible to include this 

procedure in a Lap Time Software. That 

is the objective: to improve the car time 

in a circuit. We will be able to simulate 

a car with suspension complet ¡¡¡¡ 

55


GP3 — SETUP OPTIMIZATION 

Tje principale objective is to improve the damper; this study is based from Post Rig analisys with aerodynamic 

NON DYNAMIC OR TRANSIENT; alls aerodynamics data are in the GP3 manual. 

First, the principales data setup of GP3: 

Wheelbase: 2780 mm 

Track (front): 1585 mm 

Track (rear): 1520 mm 

Weight: 550 Kg (without driver) 

Motion Ratio (front): 1,115 (wheel/spring) 

0,897 (spring/wheel) 

Motion Ratio (rear): 1,283 (wheel/spring) 

0,779 (spring/wheel) 

P3 SPRINGS 

FRONT 

REAR 

lb/in N/mm lb/in N/mm 

Stiffness: 1300 max 227,7 Stiffness: 1000 max 175,1 

1200 210,2 900 157,6 

1100 192,6 800 min 140,1 

1000 min 175,1 

Conversion factors 

1 lbf 4,4483 N 

1 in 25,4 mm 

56


GP3 ANTIROLL BARS (FRONT) 

Stiffness @ Ground (Kg/mm) 

Blade Position 

1 2 3 4 5 

ARB Configuration Full Soft Full Stiff 

170mm Blade / Rocker outer point 61,79 80,00 112,23 134,22 141,41 

170mm Blade / Rocker inner point 32,96 42,68 59,87 71,60 75,43 



Stiffness @ Ground (N/mm) 


1 2 3 4 5 






57


GP3 ANTIROLL BARS (REAR) 

Stiffness @ Ground (Kg/mm) 


1 2 3 4 5 


30x5 ARB Body / Rocker outer 

point 

49,26 62,58 84,98 99,46 104,06 

30x5 ARB Body / Rocker inner 

point 

34,21 43,46 59,02 69,07 72,27 


point 

33,92 39,76 47,75 52,00 53,23 


point 

23,56 27,61 33,16 36,11 36,97 

Stiffness @ Ground (N/mm) 


1 2 3 4 5 



point 

483,24 613,91 833,65 975,70 1020,83 


point 

335,60 426,34 578,99 677,58 708,97 


point 

332,76 390,05 468,43 510,12 522,19 


point 

231,12 270,85 325,30 354,24 362,68 

58


GP3 DAMPERS 

Damper: FRONT 

Valving: 744 

Manufacturer: 

KONI Force (N) Stiffness (Ns/mm) 

Click MIN. Click MAX. Click MIN. Click MAX. 

Speed (mm/s) Rebound Bump Rebound Bump R B R B 

0 0 0 0 0 - - - - 

10 61 -59 261 -296 6,1 -5,9 26,1 -29,6 

12 76 -70 379 -379 6,3 -5,8 31,6 -31,6 

15 97 -91 439 -438 6,5 -6,1 29,3 -29,2 

17 119 -111 474 -476 7,0 -6,5 27,9 -28,0 

23 161 -157 540 -543 7,0 -6,8 23,5 -23,6 

27 215 -220 600 -601 8,0 -8,1 22,2 -22,3 

40 354 -343 723 -741 8,9 -8,6 18,1 -18,5 

50 413 -415 819 -835 8,3 -8,3 16,4 -16,7 

70 512 -504 1015 -1026 7,3 -7,2 14,5 -14,7 

90 598 -587 1194 -1188 6,6 -6,5 13,3 -13,2 

100 637 -626 1269 -1219 6,4 -6,3 12,7 -12,2 

150 848 -820 1617 -1343 5,7 -5,5 10,8 -9,0 

200 1069 -1036 1758 -1440 5,3 -5,2 8,8 -7,2 

300 1562 -1340 1944 -1410 5,2 -4,5 6,5 -4,7 

400 1799 -1460 2128 -1439 4,5 -3,7 5,3 -3,6 

clicks 

choose click Stiffness 

0 = 

Ns/ 

60 0 2,8 

open 

mm 

7 = close 

mm 

Ns/ 

280 1 5,5 

speed 10 mm/s 2 8,3 

Ns/ 

mm 

3 11,0 

Ns/ 

mm 

4 13,8 

Ns/ 

mm 

5 16,5 

Ns/ 

mm 

6 19,3 

Ns/ 

mm 

7 22,0 

Ns/ 

mm 

59


GP3 DAMPERS 

Damper: REAR 

Valving: 745 

Manufacturer: 

KONI Force (N) Stiffness (Ns/mm) 

Click MIN. Click MAX. Click MIN. Click MAX. 

Speed (mm/s) Rebound Bump Rebound Bump R B R B 

0 0 0 0 0 - - - - 

10 66 -58 261 -281 6,6 -5,8 26,1 -28,1 

12 84 -71 300 -371 7,0 -5,9 25,0 -30,9 

15 100 -96 338 -432 6,7 -6,4 22,5 -28,8 

17 123 -110 368 -472 7,2 -6,5 21,6 -27,8 

23 169 -158 416 -503 7,3 -6,9 18,1 -21,9 

27 212 -226 476 -608 7,9 -8,4 17,6 -22,5 

40 271 -347 579 -743 6,8 -8,7 14,5 -18,6 

50 322 -421 669 -831 6,4 -8,4 13,4 -16,6 

70 402 -527 828 -1016 5,7 -7,5 11,8 -14,5 

90 471 -604 990 -1185 5,2 -6,7 11,0 -13,2 

100 508 -652 1071 -1279 5,1 -6,5 10,7 -12,8 

150 675 -841 1445 -1591 4,5 -5,6 9,6 -10,6 

200 864 -1055 1834 -1696 4,3 -5,3 9,2 -8,5 

300 1300 -1519 2160 -1845 4,3 -5,1 7,2 -6,2 

400 1806 -1727 2327 -1966 4,5 -4,3 5,8 -4,9 

clicks 

choose click Stiffness 

0 = 

Ns/ 

62 0 2,6 

open 

mm 

7 = close 

mm 

Ns/ 

271 1 5,2 

speed 10 mm/s 2 7,8 

Ns/ 

mm 

3 10,5 

Ns/ 

mm 

4 13,1 

Ns/ 

mm 

5 15,7 

Ns/ 

mm 

6 18,3 

Ns/ 

mm 

7 20,9 

Ns/ 

mm 

60


GP3 TYRES 

Tyres: 

FRONT 

Tread: SLICK GP3 ROLLING RADIUS (front tyre) 

Size: 250/570-13 

Rim: 10.0Jx13 Vertical Load (Kg) Stiffness 

Weight (Kg): 6,8 Speed (Km/h) 100 200 300 400 500 N/mm 

Pressure (bar): 1,2 0 278,5 278,1 277,7 277,3 276,9 2450,0 

Camber (deg): 0 20 278,6 278,2 277,8 277,3 276,9 2305,9 

Inflated radius(mm): 285,7 40 278,6 278,2 277,8 277,4 277 2450,0 

60 278,7 278,3 277,9 277,5 277,1 2450,0 

80 278,8 278,4 278 277,6 277,2 2450,0 

100 279 278,6 278,2 277,8 277,4 2450,0 

120 279,2 278,8 278,4 278 277,6 2450,0 

140 279,4 279 278,6 278,2 277,8 2450,0 

160 279,7 279,3 278,9 278,5 278,1 2450,0 

180 280 279,6 279,2 278,8 278,4 2450,0 

200 280,3 279,9 279,5 279,1 278,7 2450,0 

220 280,7 280,3 279,9 279,5 279,1 2450,0 

240 281,1 280,7 280,3 279,9 279,5 2450,0 

260 281,6 281,2 280,8 280,4 279,9 2305,9 

280 282,1 281,7 281,3 280,8 280,4 2305,9 

300 282,6 282,2 281,8 281,4 281 2450,0 

All units in mm 

61


GP3 TYRES 

Tyres: 

FRONT 

Tread: SLICK GP3 LOADED RADIUS (front tyre) 

Size: 250/570-13 



Pressure (bar): 1,2 0 280,1 274,5 268,9 263,3 257,7 233,3 

Camber (deg): 0 20 280,1 274,6 269 263,3 257,7 233,3 

Inflated radius(mm): 285,7 40 280,2 274,6 269 263,4 257,8 233,3 

60 280,3 274,7 269,1 263,5 257,9 233,3 

80 280,4 274,8 269,2 263,6 258 233,3 

100 280,6 275 269,4 263,8 258,2 233,3 

120 280,8 275,2 269,6 264 258,4 233,3 

140 281 275,4 269,8 264,2 258,6 233,3 

160 281,3 275,7 270,1 264,5 258,9 233,3 

180 281,6 276 270,4 264,8 259,2 233,3 

200 281,9 276,3 270,7 265,1 259,5 233,3 

220 282,3 276,7 271,1 265,5 259,9 233,3 

240 282,7 277,1 271,5 265,9 260,3 233,3 

260 283,2 277,6 272 266,4 260,8 233,3 

280 283,7 278,1 272,5 266,9 261,2 233,3 

300 284,2 278,6 273 267,4 261,8 233,3 


62


GP3 TYRES 

Tyres: 

REAR 

Tread: SLICK GP3 ROLLING RADIUS (rear tyre) 

Size: 290/590-13 



Pressure (bar): 1,2 0 290,1 289,4 288,7 288,1 287,4 1960,0 

Camber (deg): 0 20 290,1 289,4 288,8 288,1 287,4 1960,0 

Inflated radius(mm): 295,2 40 290,1 289,5 288,8 288,2 287,5 2063,2 

60 290,2 289,6 288,9 288,3 287,6 2063,2 

80 290,4 289,7 289 288,4 287,7 1960,0 

100 290,5 289,9 289,2 288,6 287,9 2063,2 

120 290,7 290,1 289,4 288,8 288,1 2063,2 

140 291 290,3 289,7 289 288,3 1960,0 

160 291,3 290,6 290 289,3 288,6 1960,0 

180 291,6 290,9 290,3 289,6 289 1960,0 

200 292 291,3 290,6 290 289,3 1960,0 

220 292,3 291,7 291 290,4 289,7 2063,2 

240 292,8 292,1 291,5 290,8 290,1 1960,0 

260 293,3 292,6 291,9 291,3 290,6 1960,0 

280 293,8 293,1 292,4 291,8 291,1 1960,0 

300 294,3 293,6 293 292,3 291,7 1960,0 


63


GP3 TYRES 

Tyres: 

REAR 

Tread: SLICK GP3 LOADED RADIUS (front tyre) 

Size: 290/590-13 



Pressure (bar): 1,2 0 290,2 285,2 280,2 275,2 270,1 195,0 

Camber (deg): 0 20 290,2 285,2 280,2 275,2 270,2 196,0 

Inflated radius(mm): 295,2 40 290,3 285,3 280,2 275,2 270,2 195,0 

60 290,4 285,3 280,3 275,3 270,3 195,0 

80 290,5 285,5 280,5 275,5 270,5 196,0 

100 290,7 285,7 280,6 275,6 270,6 195,0 

120 290,9 285,9 280,8 275,8 270,8 195,0 

140 291,1 286,1 281,1 276,1 271,1 196,0 

160 291,4 286,4 281,4 276,4 271,4 196,0 

180 291,7 286,7 281,7 276,7 271,7 196,0 

200 292,1 287,1 282,1 277 272 195,0 

220 292,5 287,5 282,4 277,4 272,4 195,0 

240 292,9 287,9 282,9 277,9 272,9 196,0 

260 293,4 288,4 283,4 278,3 273,3 195,0 

280 293,9 288,9 283,9 278,9 273,8 195,0 

300 294,4 289,4 284,4 279,4 274,4 196,0 


64


VIRTUAL POST RIG SETUP (GP3-2010) 

SETUP - GENERAL 

MASSES tyre hub total 

Unsprung 6,8 15,2 22 Kg 

Unsprung 7,3 17,7 25 Kg 

Total Mass - - 670 Kg 

Sprung mass - - 576 Kg 

DIMENSIONS Wheelbase 2780 mm 

Track (front) 1585 mm 

Track (rear) 1520 mm 

MOTION RA- 

TIOS 

wheel/spring 

(front) 

1,115 

wheel/spring 1,283 

wheel/ARB 1 

SETUP - SPECIFIC 

wheel/ARB 1 

WEIGHTS FR 123 Kg 

FL 123 Kg 

RR 212 Kg 

RL 212 Kg 

Weight Distribution 36,7 % front 

ARB Front 723,68 N/mm at ground 220mm/outer/P5 

Rear 578,99 N/mm at ground 30x5/inner/P3 

SPRINGS Front 210,2 N/mm 1200 lb/in 

Rear 140,1 N/mm 800 lb/in 

DAMPERS Front Bump 13,8 Ns/mm 4 click 

Front Rebound 13,8 Ns/mm 4 click 

Rear Bump 13,1 Ns/mm 4 click 

Rear Rebound 13,1 Ns/mm 4 click 

TYRES Front 233,3 N/mm 

Rear 195 N/mm 

65


Bode plots: 

66


Damper optimum value Closest value click 

FRONT 7,835 Ns/mm 8,3 2 

REAR 12,462 Ns/mm 13,1 4 

The optimization has been carried out by 

modifying the damper settings only. The 

rest of the setup parameters remains unchanged. 

67


Comparative Results 

Base setup: 

It shows a poor behavior specially in the front with tendency to relative understeering. The global 

understeering will depend on roll stiffness distribution and tyre dynamics. 

Optimized setup: 

The damper settings have changed the front behavior, improving the front grip. But it has also improved 

the heave and pitch performance. It can be noticed a reduction in pitch and heave movements. 

Conclusions: 

The results of both base and optimized setups are not good enough. The optimized one shows 

better performance figures than the base one does. It has better grip and the aerodynamis performance 

is better, because the heave and pitch movements o f the sprung mass are lower. 

Optimize Setup Nr. 2: 

This setup shows the impact of a slight change in weight distribution. All the parameter are the 

same as in the base setup except for the damper setting and the weight distribution. These are 

shown below. 

Damper click 

FRONT Ns/mm 8,3 2 

REAR Ns/mm 13,1 4 

WEIGHTS FR 125 Kg 

FL 125 Kg 

RR 210 Kg 

RL 210 Kg 

Total Mass 670 Kg 

Weight Distribution 37,3 % front 

68


Optimize Setup Nr. 2 RESULTS: 

Notice the improvement in tyre grip, in heave and specialy in pitch. From my point of view an excess 

in rear weight worsens the vertical performance. Better results can be reached with further 

studies and the help of the team. 

69


DISPERSSION CONTAMINANTS — CFD 

Simulation made in the course of Aero and CFD (August—Timoteo Briet— 

www.tecnicaf1.es ) 

Iñaki Veci Profesor del área… Ingeniero Técnico Mecánico especialidad en Diseño 

Mecánico e Ingeniero Industrial especialidad en Vibraciones Mecánicas por la Universidad 

de Mondragón. Técnico superior en CAD Industrial y proyectista en Utillajes 

y matrices por el Centro de Estudios Técnicos Superiores Ayala. Experiencia investigadora 

en aerodinámica, Transferencia de calor, diseño de estructuras y eficiencia 

energética (Orbea, Peugeot, Audi, Fagor S Coop, Copreci). Investigación Básica 

aplicada en sistemas de recuperación de energía undimotriz. Participación en el desarrollo 

de chasis para Epsilon Euskadi. Coordinador de becarios del aula de CFD 

(Computational Fliud Dynamics) e integrante del equipo de diseño del nuevo túnel de 

viento de la Universidad de Mondragón. 

The aim of this Numerical study is to show the capabilities of CFD simulations for predicting the evolution of smokes 

and high temperature gases ejected from a tipical factory, and its impact in a surrounding habituated area. 

70


The situation is a small industry dawnhill that in its daily operations drops to the environment a certain amount of 

harmful smokes through twciminies and water vapor from a refrigeration tower. Up the hill there is placed a house 

where the concentration of the smokes is requested. 

In order to perform a trully development of the flow, special considerations has been made in the treatment of the atmospheric 

boundary layer (ABL) based on the studies performed by the Prof.dr.ir. Bert Blocken from Eindhoven University. 

As a prior results it can be notice in the following picture the effect of a 35m/s (-Y) and 10 m/s (X) wind over the ejection 

flow of the factory. 

This kind of simulations also allow to provide safe dimensions to the ejection structures. 

71


The vertical series of orange points, on top of the house represents measuring probes for the concentration of the different 

harmfull smokes and gases. In that way it could be plotted in a tipical XY graph the gradient of any variable 

along vertical axes. 

The following picture shows a plot of the distribution of SO2 ejected from the chimneis along the y axis in the hole 

domain. 

72


Last picture wants to show the contours of mass fraction of SO2 in a plane situated where the hause is placed. It can be 

saw that the X component of the wind and the interference with the water vapor ejected from the refrigeration tower, 

force the flow of SO2 to concentrate in the left side of the image. 

73


ADVERTISING 

Curso de “AERODINÁMICA Y 

SIMULACIÓN CFD”: 

En la Industria actual, necesitas saber trabajar en CFD y conocer 

aquellos 

aspectos de la Aero que no se imparten en las Universidades Españolas; 

Aprovecha esta ocasión de aprender lo que un INGENIERO 

AERONÁUTICO, INDUSTRIAL O NAVAL, ha de saber para 

incorporarse en condiciones al mundo profesional y NO PUEDE 

APRENDER EN LA 

UNIVERSIDAD. 

APROVECHA TU MES DE AGOSTO PARA ELLO. 

www.racecarsengineering.com 

74


LOW COST — SPORT CAR 

Sergio Corbera: Ingeniero Industrial, especialidad en Mecánica por la Universidad Politécnica 

de Madrid. Máster en Máquinas Avanzadas y Transportes por la Universidad Carlos 

III. Máster en Modelos y Métodos de Optimización por la UNED. Experiencia en el cálculo 

de estructuras en el sector aeronáutico. Cuatro años de Experiencia en el desarrollo de motos 

de competición en la Universidad Politécnica de Madrid, consiguiendo el Premio a la 

Mejor Innovación Tecnológica en Motostudent 2012. Experiencia en el diseño y desarrollo 

de coches de altas prestaciones tipo fórmula (Catia y Dinámica Vehicular). Investigación en 

optimización basada en algoritmos genéticos para su aplicación al ámbito estructural y la 

alta competición. 

LOW COST CAR 

Timoteo Briet Blanes, Sergio Corbera Caraballo 

Top-level engineering, cutting-edge technology, and high performance are attributes wich currently define a 

Formula One car. The characteristics of the competition, together with the high degree of competence and 

level of development, make these cars perfectly engineered machines that are fully developed to achieve 

maximum performance on all areas of a circuit. Although Formula One generates much excitement and has 

innumerable followers, the privilege of driving these marvels of engineering remains within reach of only a 

few. 

The wish of many fans of the world of Motorsport to feel the power and technology of a high-performance 

car has motivated the automobile research team headed by Timoteo Briet Blanes to begin intense research 

in order to develop a high-performance car at an affordable price that can be within reach of the majority of 

speed enthusiasts. 

75


First-rate engineering with a development that is similar to that followed in Formula One: these are the 

main foundations of this competition car. High technology and performance are features that are not always 

linked to large amounts of money. 

This is the philosophy followed in the creation of the car, and the main challenge for the engineers involved 

in its development is to manage to combine the technology and high performance of the Formula 

One and other top-level competition cars with a reasonable price. Together with the dimensions of competition 

and high performance that are the delight of the biggest track enthusiasts, the engineers are also 

trying to make it a car that is able to be road registered so that its features can be enjoyed in the urban 

environment. 

Therefore, it is a very complete concept car with very clear development objectives that make it a very 

attractive option: cutting-edge engineering and technology, high performance for its use on the track, ergonomics, 

and easy to drive in urban areas. 

High performance and low cost 

The main objective of this engineering project is to achieve high performance and low cost in the same 

car. To combine these two concepts in a balanced way is the main challenge for the engineers, since it 

requires a complete revision of the materials, fabrication methods and components of a high-performance 

automobile in order to reduce its cost without losing the performance that is characteristic of cars in toplevel 

competition. 

76


This forces the engineers to make different designs of each of the car components until they find the most 

appropriate one for achieving the desired objectives. In order to achieve this high degree of performance, 

the most sophisticated design, simulation and optimization software is used, which is similar to the soft- 

77


ADVERTISING 

ALL INFORMATION 

http://www.nebrija.com/programas-postgrado/titulos-propios/ 

master-vehiculo-competicion/vehiculo-competicion.php 

78


79


80


81


82


ALL INFORMATION 

http://www.nebrija.com/programas-postgrado/titulos-propios/ 

master-vehiculo-competicion/vehiculo-competicion.php 

83

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