MECH5030M Individual Project Report Team 27 Tarass Gorevoi (SID: 200 566 920) Supervisor: Prof. Martin Priest Examiner: Prof. Tim Cockerill “Formula Student Engine: Design and Construction of F15 Cooling System" Date: 1st May 2014

SCHOOL OF MECHANICAL

ENGINEERING

TITLE OF PROJECT PRESENTED BY IF THE PROJECT IS INDUSTRIALLY LINKED TICK THIS BOX AND PROVIDE DETAILS BELOW THIS PROJECT REPORT PRESENTS OUR OWN WORK AND DOES NOT CONTAIN ANY UNACKNOWLEDGED WORK FROM ANY OTHER SOURCES. SIGNED DATE

Design and Construction of F15 Cooling System

Tarass Gorevoi

COMPANY NAME AND ADDRESS:

N/A

INDUSTRIAL MENTOR:

MECH5030M TEAM PROJECT 60 credits

Abstract

Engine overheating issues are of a high importance for Formula Student (FS) competition;

therefore, it is essential to understand every aspect of the cooling system. This report is mainly

focused on the analysis of the air flow through the side pod with various angles of attack of

radiator and design analysis of the side pod. Computational Fluid Dynamics (CFD) was a main tool

for this study and all simulations were based on the University of Leeds F15 prototype. The report

also highlights the main cooling system areas which needs developments.

During this study the side pod 3D CAD model was build first, along with the radiator 3D model. For

the analysis, the speed of flow was used as a top speed at FS competition which was taken as 27.78

m/s in the CFD package ANSYS 14.5. Five different designs were produced to choose the optimal

one for our particular case. Flow inside the side pod, pressure distribution on the radiator and

aerodynamic coefficients (Cd, Cl) were recorded. Using the optimum side pod, the radiator angle of

attack was changed vertically from 0 to 45 degrees in order to determine the most efficient

position. It was found that the angular setup of the radiator at 10 degrees showed the best cooling

performance as well as aerodynamic characteristics. The heat transfer rate was 12% higher rather

than 45 degree setup, which was used on last year’s LFRT car.

Acknowledgements

I would not have been able to finish my individual project without the academic and practical input

of the following people:

Professor Martin Priest - for guidelines and support throughout the project.

Dr Carl Gilkeson - for help given during my CFD simulation setup.

Mr. Jonathan Stephenson, Tony Wise – for all their assistance in practical work.

I would also like to thank everyone in the University of Leeds Formula Student Team 2014 for

contribution into building F15 race car.

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Table of Contents Table of Contents ................................................................................................................................. 1

Table of Symbols ................................................................................................................................... 3

1. Introduction ...................................................................................................................................... 4

1.1 Aims and objectives .................................................................................................................... 5

1.2 Formula Student ......................................................................................................................... 5

2. Literature Review.............................................................................................................................. 6

2.1 Liquid-cooled combustion engine system .................................................................................. 6

2.2 Thermostat .................................................................................................................................. 7

2.3 Water Pump ................................................................................................................................ 8

2.4 Radiator ....................................................................................................................................... 8

2.5 Cooling Fan ................................................................................................................................ 10

2.6 Coolant sensors ......................................................................................................................... 11

2.7 Aerodynamics ........................................................................................................................... 12

2.8 CFD ............................................................................................................................................ 13

3. Methodology .................................................................................................................................. 14

3.1 Critical Analysis ......................................................................................................................... 14

3.1.1 Thermostat ......................................................................................................................... 15

3.1.2 Water pump cover ............................................................................................................. 15

3.1.3 Cooling Fan ......................................................................................................................... 16

3.2 Side Pod Design ......................................................................................................................... 17

3.2.1 Mesh Dependency Study, CFD Setup ................................................................................. 17

3.2.2. Side Pod Design Analysis ................................................................................................... 21

3.2.3 Radiator Angle of Attack .................................................................................................... 22

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3.3 Manufacture, Assembly and Testing ........................................................................................ 23

4. Results ............................................................................................................................................. 24

4.1 Side Pod .................................................................................................................................... 24

4.2 Radiator Angle of Attack ........................................................................................................... 27

5. Discussion ....................................................................................................................................... 28

6. Conclusion ...................................................................................................................................... 30

6.1 Recommendations for future works ......................................................................................... 31

7. References ...................................................................................................................................... 32

Appendix A: Enclosure dimensions and boundary conditions ........................................................... 34

Appendix B: Radiator top mounting bracket drawing ....................................................................... 35

Appendix C: Radiator bottom mounting bracket drawing ................................................................. 36

Appendix D: Side pod design final renderings on F15 Chassis ........................................................... 37

Appendix E: Cooling system final assembly 3D CAD model renderings ............................................. 38

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Table of Symbols

Cd - Drag Coefficient

Cl - Lift Coefficient

3D - three-dimensional

CFD - Computational Fluid Dynamics

CPU - central processing unit

SAE - Society of Automotive Engineers

FS - Formula Student

LFRT – Leeds Formula Race Team

IC - Internal Combustion

SI - Spark Ignition

ECU - Engine Control Unit

CFM - cubic feet per meter

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1. Introduction

Engines running on gasoline do not convert all the energy from combustion into useful work. The

majority of the heat has to be dissipated using a cooling system. This has to be done effectively, as

the engine has to run at its optimum temperature to provide the most efficient performance.

Furthermore, the cooling system should dissipate enough heat even under maximum loading

conditions (1). On the other hand, the cooling system should not be excessively big as this would

result into a considerably higher cost, unnecessary weight gain and could result in the engine

overcooling. However, some form of a cooling system is essential for the engine to run at its

optimal ability and the design of the cooling system itself is usually built on optimization and

careful analysis of every cooling system component.

The main task for this project is to build a working cooling system for the F15 Leeds Formula Race

Team car, which uses a KTM 450EXC single-cylinder engine which was constructed in 2009. The

cooling system for this engine was previously modified from a default one because it is used on a

car which is heavier than a bike for which this engine is used. Furthermore, the engine sits behind

the driver’s seat which restricts the air flow around the engine meaning that more heat needs to

be rejected using a radiator with a fan. In addition to that, Formula Student competition has a low

average speed, which means that sufficient flow rate still has to be provided by a fan. Among many

other small factors, packaging of all cooling system components has to be made wisely, due to the

fact that a well packaged system will weigh less.

This report mainly focuses on the CFD analysis undertaken to increase efficiency of the previous

cooling system by building an efficient side pod for the particular radiator and by changing the

angle of attack of the radiator. In the analysis rotating wheels and a moving road track were set up

in the CFD package ANSYS 14.5 for a more realistic simulation. Apart from CFD, all components of

the cooling system were critically analysed to determine the areas of improvement, particularly

paying attention to a weight saving factor.

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1.1 Aims and objectives

The aim of this project is to build a working cooling system for F15 LFRT car, which uses a KTM

450cc single-cylinder engine.

The design of the Formula Student car according to FSAE rules should meet certain requirements

and when talking about cooling systems of a FS car, packaging is the one of the most important

parts. According to the task the CFD model of the cooling system is to be built and used in order to

investigate the most efficient position of the radiator, and design of the side pod.

Project objectives are as followed:

1) Complete full literature review with the purpose of createing background knowledge of

cooling systems and to understand the key areas which affect engine performance.

2) Perform a critical analysis of the current cooling system and identify areas for

improvement.

3) Create a 3D design model of the investigated system in CAD software.

4) Produce a detailed Computational Fluid Dynamics model to understand flow characteristics

for developing the cooling system.

5) Build the full cooling system and test it on the track, taking part failures and quick solutions

into consideration.

6) Draw conclusions from the above ultimately assessing the effectiveness of the new design

and suggesting any further potential areas for development.

7) Prepare a full project report documenting the completion of all mentioned points and pass

all details to a future team.

1.2 Formula Student

Formula Student (FS) is the most popular educational motorsport annual contest ran by Institute of

Mechanical Engineers (IMechE) held in Silverstone circuit. Teams from all over the world compete

between each other in three ‘static events’ (Cost analysis, Presentation, Engineering Design),

where teams are judged on their presentation, costing skills, and their design justification. There

are also five ‘dynamic events’ (acceleration, skid pan, autocross, efficiency, endurance) where the

performance of the car is tested as well as the student drivers (2). The LFRT is competing in FS this

year with its 15th formula car, F15.

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2. Literature Review

Nowadays everybody is using automotive transport in one way or another, which is powered by

the engine. In most cases it is an internal combustion engine, where the temperature in the

combustion chamber reaches 2000oC (3). Without the cooling system these kind of temperatures

would lead to overheating of the engine components and as a consequence would lead to

functional failure. For this reason, air or water cooling is necessary. For an air-cooled system a

radiator, hoses and water pump is not needed because engine is cooled just by airflow around the

engine unit. Direct cooled engines were popular in the motorcycling industry and were rarely used

in automotive engineering, due to the size of the engines and the bodyworks structure. Even

though the water pump reduces engine efficiency and a radiator with hoses adds weight, it is

necessary for most of the modern IC engines to use liquid-cooling systems to produce enough heat

release.

2.1 Liquid-cooled combustion engine system

The FS car engine is only allowed to be cooled by water (2), and due to that a liquid-cooled system

had to be investigated in detail.

In liquid-cooled systems water or antifreeze is

circulated in a closed circuit. Liquid takes heat

from the cylinder walls and their heads and

transmits it through the radiator into the

environment by circulating in passages of the

engine and hoses with a radiator. In some cases,

the direction of flow can be controlled and water

can circulated first through the most heated parts

(valves, spark plugs, the combustion chamber

walls). Chamber walls heat due to the conversion

of a fuel energy, and almost one third of it has to

be dissipated by a cooling system (4). Heat from chamber walls is then transferred to the liquid in

passages by convection. The convection heat transfer system is shown on Figure 1, where hot

gases inside a chamber (red) are transferring heat through the chamber wall (grey) to liquid inside

Figure 1: Convection heat transfer in IC engine.

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the cooling passage (blue). Therefore, directly by the temperature of the coolant we can control

the temperature at which the engine operates at.

In more detail with graphical representation, a liquid-cooled closed circuit system of a standard IC

engine is described below.

Figure 2: Standard cooling system of IC engine (5).

Figure 2 shows a big circuit which consists of thermostat, radiator and two coolant hoses. There is

also a small circuit, which is a coolant not passing through the radiator but returning straight back

into engine. This circuit is used for quicker warming at the start of the engine and is controlled by a

thermostat. The working process of thermostat is described in depth in chapter 2.2.

2.2 Thermostat

The thermostat automatically regulates the

temperature of liquid for a quicker engine warm up

after starting. The thermostat decides which circuit is

going to be used, small or big, in order for the cooling

liquid to pass through. The principle of the operation

of the thermostat is very simple: a sensor is placed

inside it, which is usually made from a wax pellet

element. The wax pellet thermostat valve is activated

by a temperature sensitive wax power element containing a mixture of wax and various other

Figure 3: Thermostat structure and flow direction (3).

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substances. The power element expands, when the temperature of a cooling liquid reaches a

certain temperature, usually about 80oC (6). The expansion of the power element opens the valve

and allows fluid to flow to the radiator. Figure 3 points out that when the thermostat valve is

closed, cooling liquid is going straight to the water pump. When the valve opens, then all the

cooling liquid from the engine will go to the radiator, and passage leading to the water pump will

be closed by the thermostat.

2.3 Water Pump

Water pumps used in the modern IC engines are either mechanically or electrically driven. The

engine used by LFRT is installed with a mechanical pump which circulates the coolant through all

cooling system parts, and helps to overcome any pressure losses occurring in the system. A

detailed description regarding pumps is beyond the scope of this project.

2.4 Radiator

The efficiency of the vehicle cooling system strongly depends on the air flow through the heat

exchanger. The flow through the heat exchanger in turn depends on the specific size and core

design of the radiator. The basic radiator design is shown below:

Figure 4: Basic radiator design with components highlighted.

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Today, there are three basic types of heat exchangers used in the automotive industry (7):

a) Flat plain tubes with parallel plate fins.

b) Cylinder tubes mechanically bonded with parallel plate fins.

c) Flat tubes with corrugated fins.

Figure 5: Basic automotive heat exchanger design options (7).

Different designs have different advantages and disadvantages taking the cooling performance

efficiency, ease of manufacturing, packaging and overall cost into consideration. Fins are used in all

of the modern radiators as the most efficient way of increasing surface area of a heat exchanger

(8) without blocking the airflow passing through the radiator.

The cross flow radiator available to the Leeds Formula Race Team has design C shown on Figure 5.

In order to calculate the cooling performance of this type of heat exchanger, the ε-NTU approach is

used (7). The ε-NTU analysis is based on simple calculations of the heat loss and heat gain taking

place between cooling liquid and air.

Heat loss by a coolant: ( )

Heat gain by air: ( )

Where - overall heat transfer (kW), - mass flow rate (kg/s), - specific heat capacity (kJ/kgK),

T - temperature, h - hot fluid (coolant), c - cold fluid (air), i - inlet, o - outlet.

From the above the ability of fluid to absorb heat is represented as a capacity rate for both hot and

cold fluids:

;

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Capacity ratio C* is then defined as: C*=Cmin/Cmax, where Cmin is the lowest value out of two capacity

rates and Cmax is highest value.

The number of transfer units (NTU) is found by:

, where A - total heat transfer area,

overall heat transfer coefficient.

Maximum heat transfer rate possible: ( )

Considering that effectiveness ε is just a ratio of actual heat transfer to the maximum, therefore it

can be concluded that: ( )

With an established effectiveness, the process of obtaining heat dissipation for a given heat

exchanger becomes relatively straight forward. To conclude, such a relationship was proven by

several researchers (8, 9, 10): ( ).

Also, inclination of the radiator against the vertical

axis helps without increasing drag. It also improves

cooling performance as it is used in Formula 1 due

to an increase of the heat exchanger surface area,

where the inlet area stays the same. Setup of

radiators in one of the 2008 Formula 1 cars is shown

on Figure 6.

2.5 Cooling Fan

A cooling fan is used to control the airflow subsystem in order to achieve a sufficient air mass flow

rate, taking power consumption and aerodynamic noise into consideration.

For the Formula Student competition, implementation of a cooling fan is very important due to low

speeds of the car and long idling time at some of the competitions. The main suggestion is to use

the biggest fan possible (12), but not to overlap the radiator tanks, which will mean that fan is

running against a flat surface. Apart from the fan diameter, the size of the motor and the blade

design are other important characteristics. All of them define the speed of a fan responsible for

volumetric flow rate through the radiator, which in the automotive industry is often measured in

Cubic Feet per Metre (CFM). The established Fan Laws (7) help to compare fan performance using

Figure 6: Scuderia Toro Rosso radiator layout (11).

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more than just one parameter. There are two dimensionless parameters: flow coefficient and

pressure coefficient

Where is volumetric flow rate, Afan is swept area of fan and Vtip is fan tip velocity.

Where is air density, is total pressure. All unknown value could be found using three other

equations, data of which is usually given on a fan manufacturing technical characteristics sheet.

Volumetric flow rate (m3/s):

Total pressure:

Fan swept area is approximately:

Fan tip velocity:

Flow coefficient and pressure coefficient when plotted produce a pressure-flow curve, which helps

to compare the size of different speed fans, or compare the performance of different sized fans.

The position of the fan is crucial, but for the FSAE competition where there is free flow around the

car and the radiator is not placed under the bonnet, like on modern cars, the fan will always be

placed behind the radiator not interrupting the flow, thus decreasing drag force. No shroud is

generally used on FS racing cars due to additional weight and air blockage at speeds over 60 km/h

(13).

2.6 Coolant sensors

An engine coolant temperature sensor could be found in all modern IC engines, which records the

temperature of the coolant. The coolant sensor is directly connected to ECU, which receives

readings from the sensor in resistance and then in ECU it is converted to temperature in oC. When

the engine is overheating, that means that the coolant temperature is too high and usually a signal

from the sensor is led to a light which comes up on a dashboard. The coolant inside cooling system

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is not allowed to run either too hot or too cold, so with control of the fan speed from 0 to

maximum, the optimum operating temperature can be achieved.

2.7 Aerodynamics

Adequate cooling in automotive industry is

achieved by controlling the airflow around the

engine and cooling system components. For

the FS competition where open wheel race

cars are involved, it is more important to lead

the flow most efficiently into the heat

exchanger (radiator). In this case, efficient

means that flow should provide a sufficient

amount of air flux and have a low drag. The

LFRT car has a steel space frame chassis with

bodyworks made from composite material

which gives plenty of aerodynamic modifications.

There are several publications available, covering the improvement of flow through the side pod,

which is directly connected to the cooling system performance. In most cases CFD was used to run

an essential numerical simulation solving aerodynamic problems. Kamath (14) suggests to use side

pod converged from both ends, increasing the effective time for the heat transfer to take place,

increasing the heat rejection efficiency. Such a design enables to reduce the air velocity at the core,

which reduces drag force created by a radiator, shown on Figure 7. Data on Figure 7 is based on

experiments done before World War II (15). Important factors for the inlet design of the side pod

are area, edge radius and location. Location of the side pod is more or less fixed by FSAE rules (2),

as it has to be further than 70mm (size of a tennis ball) from the front wheel, and logically it has to

be as close as possible to the engine and cooling components inlet/outlet to save piping length,

thus saving weight. The optimum edge radius could be found using CFD to insure the air flow is

evenly distributed inside the side pod, thus covering the whole size of the radiator. The inlet area is

also usually determined by simulations, but Carroll Smith (15) showed that it has to be no smaller

than 60-75% of the cross-sectional area of the radiator. A smaller inlet area will decrease cooling

efficiency at yaw conditions when cornering. It was proven in several studies (16, 17) that sealing a

Figure 7: Advantage of using side pod for cooling system (15).

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gap between the radiator and the side pod increase the turbulence, thus increasing the drag force

without the improvement of the heat exchanger performance. Also, an inclined radiator increases

cooling efficiency of the radiator with the decrease of drag (17). Overall it could be said that a more

complex side pod design reduces the overall drag of the car, especially the one created by wheels

and lead the airflow further around the engine, providing additional cooling.

2.8 CFD

As mentioned above, today, most of the aerodynamic problems are solved using CFD, which allows

us to produce a realistic model of interaction between an object and a fluid. Computers run such

simulations and millions of operations could be performed simultaneously, saving time and

financial resources. CFD involves three steps: pre-processing, solving partial differential equations

and post-processing. The middle step is always the most time consuming operation due to the

complexity of the air flow and object in many cases. It is also very much linked to the quality of pre-

processing, which involves parameters input and CAD model of an object.

Many racing teams choose to use CFD software because no actual construction has to be made in

order to solve aerodynamic problems, which saves the cost of building and experimenting on an

actual race car. On the other hand accuracy and validity of the results must be considered when

analysing software simulations. Most of the CFD results have to be compared to experimental

prototype results from wind tunnel testing. Testing has shown that CFD results are pretty accurate

and lay within 10% of the experimental data (18).

The ANSYS FLUENT version 14.5 software which is widely used for CFD Analysis is available for use

at University of Leeds. It is a well-known tool for modelling fluid flow, heat transfer and different

turbulence models. Workflow on the FLUENT is similar to all other CFD packages (Figure 8).

Figure 8: CFD analysis workflow using SolidWorks and ANSYS Workbench.

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3. Methodology Last year’s LFRT car did not make it to the

competition, which shows the complexity of the

whole project which involves tight timescales for

subprojects. In order to complete all objectives

stated in Contract Performance Plan (CPP) for

cooling system work package on time it was

decided to use spiral sequence engineering

model. This model helps to work on a complex

product within a team with shared objectives

and it was chosen because several prototypes

have to be tested in CFD with importance of

continuous improvement before the final design

could be produced. Spiral sequence model is shown on Figure 9, where customer requirements are

taken from CPP, and at the very top of the model a critical analysis of the current cooling system

and identification of areas for improvement can be added.

3.1 Critical Analysis

There was plenty of work done for F14 LFRT car cooling system with usage of two standard KTM

EXC450 radiators equipped by small fans, showing the heat transfer coefficient to be 67.8W/m2K,

which is higher than usual for the same sized radiator (19), highlighting fin efficiency and good

design. Last year it was agreed that one radiator would be implemented only on one side of the

driver into side pod. The decision was made simply by the radiator size and a similar fin design. The

KTM 450EXC two standard radiators combined frontal area is equal to 0.0587 m2 whereas the race

spec radiator manufactured by Pace Products (PP) in 2010 has a total area of 0.0588 m2. Also, both

radiators have similar thickness. With assumption of a better core design than the standard KTM

450EXC radiators it could be easily said that the use of one PP radiator is enough to provide

sufficient cooling for the 450cc engine. Another factor which supports moving to one radiator

rather than two is better packaging, as piping should lead only to one side of the car. Furthermore,

one PP radiator weights 70% of two KTM 450EXC radiators. The radiator is equipped with a 7.5”

fan, characteristics of which are unknown, probably due to loss of the technical description sheet.

Figure 9: Spiral sequence engineering approach. (7)

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Another important part of the cooling system is the thermostat which is sometimes removed from

the engine as it was done last year. However, due to insufficient documented information, this

area is yet to be reviewed. As packaging and weight saving are very important for any race car

performance, piping routes and modifications of the engine water pump cover were also reviewed

below. Following the critical review, it was found that there is no data for the previous side pod

designs and a radiator angle of attack simulation was not undertaken, which was the deciding

factor of the area this report will be focused on. Optimization of the air flow through the radiator

directly improves the heat exchanger performance. Furthermore, the overall drag and lift forces

could be reduced - perfecting the aerodynamic characteristics of a car (16).

3.1.1 Thermostat

In order to validate the operating temperature of the thermostat, a small experiment was set up to

check temperature at which the thermostat is actually fully opening and fully closed. With this

experiment the optimum coolant temperature stated by KTM engineers was validated. For the

experiment the thermostat was submerged in a glass of water with a thermometer. The glass was

then placed on an electrical hob. By gradual increase of temperature the thermostat was observed

and the following results were recorded: the thermostat valve activated at 68oC which reached its

fully open condition at 78oC. Technical specifications state that the operating temperature of the

thermostat used in KTM450 EXC engine is 70oC.

As the thermostat is designed for a quicker warm up and considering the fact that operating

conditions at Silverstone during July have a relatively high temperature with the engine sitting at

the back of the driver which limits airflow cooling, there should be no problem with overcooling

the engine at the beginning. Therefore, thermostat is not going to be used this year, but could be

easily implemented if needed as all spare parts are available. Removing the thermostat will save

weight gain as thermostat weights 41g and extra piping with water is around 273g more. Whilst it

is important with such a small engine to keep the overall weight of the car as small as possible,

every gram counts.

3.1.2 Water pump cover

The water pump cover is designed in such way that inlet is facing left hand side of the vehicle

(looking from the back), meaning that the piping should go straight under the exhaust manifold.

This setup will be accompanied by unnecessary heat of coolant, thus modification of water pump

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cover was investigated in order to lead the piping straight into side pod situated in right hand side

of the car.

There are several possibilities of improving the design:

Weld 180 degree bend to the water pump cover short

inlet pipe of same diameter made from aluminium.

Cut the short inlet pipe and weld it from the other side.

Cap the existing short inlet pipe and a drill a hole from the

other side of the water pump cover attaching the necessary

piping.

Use bigger diameter short 180 degree bend silicone hose

attached to the end of the inlet.

Manufacture a new water pump cover.

Due to complex geometry, drastic modifications will decrease the water flow rate and increase

piping loss. Considering that the water pump cover is made from aluminium alloy the welding

option becomes unavailable, as stated by University of Leeds technician. Manufacturing a new

water pump cover was considered to be unnecessary with the high cost and small weight saving

point of view. A bigger diameter 180 degree silicone hose will be used as the cost-effective solution

to weight reduction and unnecessary heating of coolant problem.

3.1.3 Cooling Fan

There are three different types of fans available for LFRT this year: 4” KTM 450EXC standard fans,

8.5” fans used on F12 car and 7.5” fan. The optimum size for a chosen radiator is 8”, as it will cover

all of the core area without overlapping radiator side tanks. A problem was faced as no technical

characteristics were available for the 7.5” fan. With the help of a tachometer RPM was recorded

and then converted to CFM, using a formula:

. The results showed that the fan

is very similar to the SPAL Automotive 7.5” fan producing

437 CFM (20). Considering the age and characteristics of

the old fan, it was decided to buy a new high performance

8” fan which provides 1400 CFM.

Table 1: Old and new cooling fan specifications.

7.5” fan 8” fan

Performance 437 CFM 1400 CFM

Weight 814g 825g

Cost 96.22 £ 22.96 £

Power 80 W 80 W

Figure 10: 3D CAD model of KTM450EXC water pump cover.

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With only a small change in weight, we experienced a big advantage in performance. Taking into

account that there is an assessed Cost Report at the Formula Student competition, the cost of the

fan in comparison to the previous fan came at 75% cheaper.

3.2 Side Pod Design

In order to create an efficient side pod for cooling purposes of LFRT car several factors need to be

considered:

Radiator size with ability to change its angle from 0 to 45o relative to vertical plane

Heat transfer rate of radiator

Inlet/Outlet size analysed in literature review

Airflow characteristics

Radiator pressure profile, to validate even distribution of air flow through radiator

Drag and lift forces to analyse aerodynamic characteristics of radiator

The first step is to model a side pod and radiator as 3D CAD models. The SolidWorks 2013 edition

was used to create an assembly of simple geometry, which could then be easily imported into

ANSYS Fluent 14.5 as the main CFD software used during this report. All CFD analysis undertaken

during this project is based on 3D problem simulations.

3.2.1 Mesh Dependency Study, CFD Setup

Baseline model was first built in order to carry out mesh dependency study which is necessary in

providing consistent results with smaller possibility of errors in future simulations. The baseline

model is clearly shown on Figure 11.

Figure 11: Side pod baseline model for CFD simulation.

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Geometry of the side pod was checked against the F15 chassis CAD model, making sure it fits

between the wheels and follows the rules mentioned in chapter 2.7.

Geometry of the radiator is simplified and all

surfaces are rounded to reduce the risks of

errors as well as save computational time. With

such a setup (Figure 11), the side pod inlet is

72.5% of the size of the radiator. The outlet of

the side pod is made 15% bigger than size of the

radiator in order to decrease the pressure and

lead the flow around the rear tires. The gap

between the radiator and side pod is not sealed,

the radiator is floating in air 100mm from the

back of the side pod, as the optimum position for

further inclination, so that radiator stays inside a

side pod at all times. It was also found that creating an enclosure around the side pod with the

radiator fitted is much easier in SolidWorks rather than ANSYS Workbench. The size of an

enclosure was taken to be standard for the CFD automotive engineering problems: 3 object lengths

at the front and 5 lengths behind as suggested by Lanfrit (21). The size of the radiator:

length=530mm, width 290mm front, 180mm back and height 305mm. Thus, overall length of the

domain is then 4770mm. The enclosure geometry could be seen in more detail in Appendix A, as

well as named selections used during all CFD simulations. Named selections help to specify

boundary conditions making the CFD analysis close to real life conditions.

Successfully importing the full 3D CAD model of the side pod with the radiator assembly in an

enclosure, the meshing procedure has to be undertaken. The first step was to do a mesh

dependency study to find the optimum mesh size in order to provide the most accurate results as

well as save computational time. Under the mesh setup, sizing on proximity and curvature with a

medium relevance centre and medium smoothing was selected. Due to a curved and relatively thin

radiator plates the fine span angle centre was used as well. In order to control the mesh of the side

pod and the radiator, face sizing for both objects was added with an element size of 70mm and

Figure 12: F15 Radiator CAD model for CFD with dimensions.

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7mm respectively to keep the ratio of 1:10, suggested by Lanfrit, between two objects for

automotive CFD applications (21). All other settings were left as default.

The next step was to specify all parameters in FLUENT in order to run the simulation and receive

the data for drag and lift force, so that the mesh dependency study could be undertaken. The main

component which needs to be prioritised is accurate prediction of flow separation in the CFD

simulation involving smooth surfaces. As for the automotive industry standards, shear stress

transport (SST) k-omega turbulence model is best known for problems involving separating flows

which gives highly accurate results compared to other turbulence models used in FLUENT. Also, as

flow is going close to the walls involving boundary layer, it is suggested in experiments of Bardina

(22) to use the SST k-omega model. Furthermore, in ANSYS FLUENT 14.5 User’s Guide it is

recommended to use smaller turbulence intensity for velocity inlet (1%) and pressure outlet (5%)

boundary conditions (23). Due to the fact that heat transfer rate of the radiator has to be recorded

in FLUENT the energy equation parameter was turned on. Also, aluminium had to be added into

FLUENT as a material to be specified for the radiator. The following properties of aluminium were

used: density 2719 kg/m3, specific heat 879 j/kg.K and thermal conductivity 202.4 W/m.K (24).

Velocity inlet was specified to be 27.78 m/s, as the highest possible speed of the FS car at the

competition. Same velocity was selected for the bottom wall parameter, in order to simulate the

moving road characteristics. The temperature of the air flow coming from the inlet was picked to

be the highest average recorded at Silverstone race circuit in July in between 1981 and 2010 –

21.7oC (25). The temperature of the radiator was fixed at the starting point to be 90oC because it is

the optimum operating temperature for internal combustion engines (26). At this temperature:

Lubricant is at its optimum state, as it has lower viscosity. Meaning, that metal parts will

wear less with overall reduction of the mechanical losses.

Fuel vaporizes completely, which provides better combustion with a less emissions.

The bias factor of 50 was chosen in solution controls and the minimum size of an element was

decreased to 0.00001 m, in order to minimize the possibility of an error during the simulation. The

Pressure-Based Coupled Solver (PBCS) was selected as a solution method, as it reduces

convergence time by five times with a small increase of the computational time. Coupled solutions

help to solve two different equations at the same time: pressure-based and momentum, thus

Page | 20

decreasing the convergence time (27). Increased computational time by PBCS model could be

neglected as high performance computers are used in for all of the simulations during this project.

All other settings in FLUENT were left as default.

Finally, the CFD simulation was ran under different meshing setting using same baseline model.

Mesh dependency study as the analytical graph is presented below:

Figure 13: Mesh dependency study for radiator in side pod assembly for F15 LFRT car.

As shown in Figure 13, after around 1,700,000 elements the results are almost stop changing,

therefore any mesh with a size over 1,700,000 elements could be used during this project,

assuming that the results are going to have minimal risk of error. Nevertheless, the closer the value

of elements to 1,700,000, the less time will be needed to complete the CFD analysis in FLUENT 14.5.

The decision was made to use a mesh

size of 1,750,000 elements with ±10%

limit in order to receive the most

accurate results for future simulations.

The final mesh of the baseline is

demonstrated in Figure 14, and will

be used in further studies of this

project.

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

23.0

24.0

25.0

26.0

27.0

28.0

3 995 092 2 573 676 1 706 466 1 226 080 784191

Lift

Fo

rce

(N

)

Dra

g Fo

rce

(N

)

Number of Elements

Mesh Dependency

Drag Force Lift Force

Figure 14: Baseline mesh visualisation.

Page | 21

3.2.2. Side Pod Design Analysis

Having the ready model with a setup, geometry of the side pod was changed without changing any

positional settings of the radiator inside it. The spiral sequence model was used to improve the

side pod design after every simulation in order to find the optimum. Both aerodynamic

characteristics (drag, lift coefficients) were analysed as well as cooling properties of the radiator

(heat transfer rate, pressure distribution). For each modification a simulation was ran and

comparison of the results gave a transparent answer to all the objectives of this project.

Modifications to the side pod design could be clearly seen in the visualisation plots in Table 3,

where all the graphical results are presented for each design. The inlet and the outlet areas were

slightly varied, but the main point of interest was the curved face of the side pod which plays a role

of a duct, as well as being responsible for even distribution of the air flow through every part of the

radiator. It is clearly demonstrated on Figure 15, where the baseline design is compared to the

modified version of the side pod. Also, due to the inclination of the face which lies between the

chassis top and bottom bar, it was decided to test the side pod inner and outer walls parallel and

outer wall just perpendicular to the ground.

Figure 15: Modified side pod design (A) and baseline model (B).

A B

Page | 22

Only final side pod CFD analysis was ran with the

rotating wheels implemented as well as the

chassis side of the radiator exactly taken by

coordinates from the CAD model of the F15 LFRT

chassis, in order to assure certainty concerning

the manufacturing of the side pod and fitting it

onto the actual car. The wheel’s angular rotating

speed inputted into the FLUENT settings was

equal to 111.12 rad/s, which is exactly 27.78 m/s

– the velocity at which the car was running in all the CFD simulations during this project. There was

also a curved flat plate added on top of the side pod (dark grey on Figure 16) to test if that would

make any difference to aerodynamic performance.

3.2.3 Radiator Angle of Attack

After finding the optimum design of the side pod, the position of the radiator was tested to

understand the influence of the radiator angle of attack. The radiator was tilted from 0 to 45

degrees. The distance between the outlet edge and the radiator was kept constant at 50mm. Also,

clearance between the side pod floor and radiator was kept as close as possible (1mm) due to the

process of mounting in real life, whereas the side pod floor is supporting the radiator. The setup of

3D analysis in FLUENT where the radiator is angled at 45 degrees is demonstrated on Figure 17.

Figure 17: Variable angle of attack CFD simulation setup.

Figure 16: Addition flat plate on a side pod, leading to the back of the chassis.

Page | 23

3.3 Manufacture, Assembly and Testing

After the finalisation of the side pod

design, a CAD model was passed to Ben

Cross, who was responsible for the F15

bodywork manufacturing process. The

side pod was made from carbon fibre

based on the fifth design shown in this

report. The entire manufacturing process

could be found in related report (31). The

actual side pod is shown on Figure 18.

The cooling system was partly tested during the rolling road test, which showed that there were no

issues with engine warm up, as well as the absence of any overheating issues. Taking into account

that during the rolling road testing the car is not moving, it could be said that new more efficient

fan provides enough air flux. The temperature of the coolant during testing was recorded to be

mainly around 80 degrees, which is optimum for that engine.

The radiator mounting brackets were manufactured in the laser cutting process, using 2mm

stainless steel. They were designed in such a way that the angular setup of the radiator could be

varied between 0 and 15 degrees. Such a design will give an easy solution for a quick change of

angular attack during track testing, which will help to validate the CFD experiment results. The

design of such brackets is shown below, as well as detailed drawings available in the Appendices B

and C.

Figure 18: Manufactured side pod with cooling system subassembled.

Figure 19: Radiator mounting brackets with variable setup of the angle of attack.

Page | 24

4. Results The main purpose of the CFD analysis was firstly to find the optimum side pod design for the F15

LFRT car, and secondly to identify the optimum positional settings of the radiator, especially the

radiator angle of attack. For all analysis several parameters were recorded: drag and lift

coefficients, heat transfer rate, as well as visualisation of the results in order to examine pressure

distribution on the radiator and air flow behaviour.

4.1 Side Pod

As described in chapter 3.2.2. several side pod designs were considered, in order to find the

optimum design. Results for all runs are shown below:

Design Model Drag Force (N) Cd Lift Force (N) Cl Heat Transfer Rate of Radiator (W)

Baseline (1st) 20.1877 0.4543 4.4960 0.1012 3023.4640

Second 20.2758 0.4563 4.7728 0.1074 3009.9960

Third 21.9170 0.4933 5.2906 0.1191 3031.6196

Fourth 23.7779 0.5351 4.8039 0.1081 3126.6180

Fifth 25.0701 0.5606 2.4200 0.0545

Table 2: Different side pod design CFD results.

For a clearer comparison of the aerodynamic and cooling characteristics received after every

design CFD simulation, Lift/Drag ratio was plotted against the heat transfer rate.

Figure 20: Aerodynamic and cooling characteristics comparison for different side pod designs.

5th

4th

3rd

2nd

1st

3000.000

3020.000

3040.000

3060.000

3080.000

3100.000

3120.000

3140.000

3160.000

3180.000

3200.000

0 0.05 0.1 0.15 0.2 0.25 0.3

He

at T

ran

sfe

r R

ate

(W

)

Lift/Drag Ratio

Lift/Drag Ratio vs. Heat Transfer Rate

Page | 25

Visualisation plots of the results for all five different designs are available below:

Flow around the sidepod (velocity streamlines) Pressure distribution profile on a radiator

Baseline

2nd (parallel walls, smaller radii of inlet wall)

3rd (inlet 3% bigger, smaller radii of inlet)

Page | 26

4th (outlet smaller by 3%, minimum to fit the radiator, changed angle between the radiator and the chassis to fit)

5th

(modified

3rd design

with inlet

15%

bigger)

Table 3: Comparison of flow around a side pods and pressure distribution profiles of a radiator for all five simulations.

Final side pod design CFD results, with exact side wall and rotating wheels:

Drag Force (N) Cd Lift Force (N) Cl Heat Transfer Rate for Radiator (W) Lift/Drag Ratio

32.10 0.5523 8.03 0.1382 2862.84 0.2502 Table 4: Final side pod design CFD results.

Percentage change of aerodynamic parameters with addition of a curved flat plate onto side pod:

Figure 21: Drag (Cd) and lift (Cl) coefficients percentage change with flat plate addition.

0.00%

20.00%

40.00%

60.00%

80.00%

100.00%

Percentage Change with flat plate

Cl

Cd

Page | 27

4.2 Radiator Angle of Attack Same parameters as for side pod design were recorded for analysis of angle of attack (α) of the radiator.

α (deg) Heat Transfer Rate (W) Drag Force (N) Downforce (N) -Cl Cd Cl/Cd

0 2650.29 34.21 -15.48 -0.2609 0.5765 -0.00763

5 2751.98 32.81 4.23 0.0723 0.5607 0.002203

10 2820.973 38.31 18.64 0.3185 0.6548 0.008314

15 2796.487 39.16 22.50 0.3845 0.6693 0.009818

20 2768.975 39.95 24.83 0.4243 0.6826 0.010623

25 2731.863 40.22 26.31 0.4496 0.6990 0.011179

30 2591.44 40.91 22.72 0.3882 0.6873 0.009491

35 2550.279 42.44 23.74 0.4057 0.7252 0.00956

40 2513.9 42.46 23.42 0.4002 0.7256 0.009424

45 2484.247 43.31 21.92 0.3839 0.7234 0.008863

Table 5: Radiator angle of attack variation CFD results.

Velocity streamlines through the radiator angled at 0 and 10 degrees and pressure distribution

profile across the radiator are shown in Table 6 located below.

0 Degrees 10 Degrees

Table 6: The flow visualisation and pressure profile through the radiator angled at 0 and 10 degrees respectively.

Page | 28

5. Discussion The results confirm that slight modification to the

initial side pod design could decrease drag force by

25%, with the cooling performance increasing at the

same time by 5%. Moreover, aerodynamic flow

characteristics improve with much smoother ducting

of the inlet, rather than straight curved which is

clearly seen in Table 3 (Design 1 and 5). During

research it was also found that making the outer side pod wall parallel to the chassis wall

decreases drag coefficient, as well as decreasing the heat transfer rate. Therefore, the frontal inlet

area is reduced if walls are parallel, rather than one wall perpendicular to the ground. Furthermore

it was recorded that with the increase of inlet size (Table 3, Design 5), pressure distribution profile

on the radiator is more even, showing that when inlet area constitutes the 90% of the frontal area

of the radiator then cooling performance and aerodynamic characteristics are at their best.

Identical observations were obtained by Da Silva (28) in his CFD analysis of the Melbourne

University Racing car side pod - with the increase of the inlet, heat transfer rate increased up to 2%

of the baseline model.

Also, it can be observed clearly on Figure 22

that the flow around the side pod goes

smoothly around the rear wheel, thus

helping to reduce the drag force acting on

the tyre. This design is numbered as 5th in

this report and validates the benefits of using

wide side pods similar to the ones used on

Formula-E cars.

Figure 22: Flow visualisation around the side pod.

Figure 23: Formula-E 2014 design (29).

Page | 29

In order to analyse the radiator angle of attack effect on cooling performance, the graph was

created based on the results presented in Table 5.

Figure 24: Heat Transfer rate of radiator for different angle of attack.

We could clearly see a peak when the radiator was angled at 10 degrees from the vertical plane,

giving us the highest heat transfer rate equalling to 2821 W, which is 12% higher than previous

years setup for LFRT car, when the radiator was angled at 45 degrees to the flow. Considering that

flow characteristics drastically change due to angle adjustment, aerodynamic forces should be

analysed when making decision at which the angle of the radiator should be placed for most

efficient performance.

Figure 25: Aerodynamics forces change with radiator angle of attack variaton.

2400

2500

2600

2700

2800

2900

0 5 10 15 20 25 30 35 40 45

He

at T

ran

sfe

r R

ate

(W

)

Angle of Attack (deg)

Angle of Attack vs. Heat Transfer Rate

-20.00

-10.00

0.00

10.00

20.00

30.00

40.00

50.00

0 5 10 15 20 25 30 35 40 45 50

Ae

rod

ynam

ic F

orc

e (

N)

Angle of Attack (deg)

Angle of Attack vs. Aerodynamic Forces

Drag Force Downforce (Negative Lift Force)

Page | 30

Figure 24 clearly represents aerodynamic forces acting on the radiator inside the side pod, where

lift force was converted into down force with simple multiplication by -1, as this parameter is

better for visual analysis. It can be observed that there is high increase of drag and down force

from 0 to 10 degrees and after that only a slight increase could be recorded. At 0 degrees down

force is negative meaning that radiator will only produce lift force which is bad for aerodynamics of

a car as a whole. Above 10 degrees, down force is varied only within 8N, which is about 800g of

additional weight on side pod, and that could be neglected taking into account the overall weight

of the F15 car (~180kg), meaning it will constitute only to a small amount of the whole

aerodynamic performance of the car. Drag force is only increasing with increase of the angle of

attack, meaning that the lower the angle is, the less drag you receive. When analysing the flow

characteristics shown in Table 6, it could be said that there is no big difference in aerodynamic

components, as the radiator is placed close to the side pod outlet, which does not create any flow

blockage. The radiator pressure profiles do not change drastically either.

6. Conclusion The effect of a different side pod design on the cooling performance and aerodynamic

characteristics of the LFRT F15 race car was studied using the CFD model simulation with

assumption that the car is running at 100km/h or 27.78m/s taking into account the average

maximum temperature recorded in July at the Silverstone circuit, where the FS competition takes

place this year. Overall, the study was performed for investigation of different side pod designs

with variation of radiator angles of attack, construction of the cooling system 3D CAD model

components based on FSAE 2014 rules and adjustment of the side pod design established by

research in literature and further analysis in CFD package ANSYS FLUENT. The judgement on the

cooling efficiency of the radiator was limited to Heat Transfer Rate, as this is the main analytical

characteristic of any heat exchanger (7), as well as aerodynamic characteristics such as drag and lift

coefficients were recorded with visualisation plots of the flow around the 3D model.

The study involved 3D analysis in ANSYS FLUENT CFD system which took a lot of effort in order to

first create necessary 3D CAD models in SolidWorks; Secondly, to import needed geometry to

ANSYS package, with further addition of a fluid domain around the object. Further selection of the

right mesh settings in order to reduce the possibility of an error and improving the speed of

Page | 31

simulation is necessary. Additionally, selection of the appropriate turbulence model and the

specification of the relevant settings for the boundary conditions is required, after which the setup

is sent to a high performance computer and the data received from the output is closely analysed.

During the study, angular settings of the radiator and the design of the side pod were found, as

well as whole cooling system for LFRT F15 car which was built including the radiator mounting

brackets with a new shorter piping route. Results showed that the 5th design of the side pod was

optimum for a chosen radiator. All necessary information was commissioned to a person

responsible for the body work manufacturing process and was subsequently made out of carbon

fibre. The radiator angular settings will be validated during later track testing where the angle of

attack will be changed from 0 to 15 degrees and the cooling performance will be recorded. Based

on that testing, a decision will be made on the setup with which we can proceed onto the

competition.

6.1 Recommendations for future works

Due to the fact that at the time of this study the engine was not in running condition, some of the

experiments could not be undertaken: volumetric flow rate of water pump of KTM450 EXC, which

would help to understand the cooling system of this particular engine much better, as well as

understanding the efficiency of the given radiator (Tin and Tout). Considering the size of PP radiator

and performance of new RaceSpec Performance cooling fan, it is suggested that implementing

cooling system at the back of the chassis just next to the engine would be more beneficial. Such a

setup will reduce weight gain, eliminating the need of the side pod and less piping. It should

therefore show, better aerodynamic characteristics, alternatively reducing the drag force created

by the radiator in side pod. Careful analysis is needed in order to validate such setup. In addition,

further investigation of the radiator positional settings could be undertaken with the change in

horizontal plane.

The side pod design could be further modified with

a more complex design in order to increase the

aerodynamic performance of the car. The

suggested design could be similar to the FS Team

Weingarten (Figure 26). Figure 26: FS Team Weingarten side pod design (30).

Page | 32

7. References

1. CALLISTER, J., COSTA, T., and GEORGE, A., The Design of Automobile and Racing Car Cooling

Systems. In: SAE Technical Paper 971835, 1997.

2. SAE. 2014 Formula SAE® Rules [online]. 2013. [Accessed 20 October 2013]. Available from:

http://students.sae.org/cds/formulaseries/rules/2014_fsae_rules.pdf.

3. LINDE, A. How your car works, Veloce Publishing Ltd, 2001, pp. 47-48.

4. STAMM, C.A. and MCCRAVEY, W.E. Cooling System Performance of Liquid Cooled Engines.

In: Paper no.440009 Engineering Department of Chrysler Corporation, 1944.

5. IGNATOV, A. and KOSAREV S., VAZ 2108-2109. Manual. Operation and maintenance,

Moscow, 1998.

6. CHIANG, E. and KELLER, J. The Thermostat Characteristics and Its Effect on Low-Flow Engine

Cooling System Performance, In: SAE Technical Paper 900904, 1990.

7. KANEFSKY, P., NELSON, V., and RANGER, M. A Systems Engineering Approach to Engine

Cooling Design. In: SAE Technical Paper 1999-01-3780, 1999.

8. KAYS, W. and LONDON, A. Compact Heat Exchangers (3rd ed.), McGraw-Hill, 1955, pp. 2-22.

9. HOLMAN, J.P. Heat Transfer (5th ed.), McGraw-Hill, 1992.

10. INCOPERA, F.P. et al. Fundamentals of heat and mass transfer. John Wiley & Sons

Incorporated, 2011.

11. SCARBOROUGH, C., Toro Rosso: Radiator layout [online]. 2008. [Accessed 12 January 2014].

Available from: http://scarbsf1.com/blog1/2011/05/19/toro-rosso-radiator-layout/.

12. HOYT G., Radiator Cooling Fans, Society of Automotive Engineers, 190041.

13. BEATENBOUGH, P., Engine Cooling Systems for Motor Trucks. In: SAE Technical Paper

670033, 1967.

14. KAMATH, S. CFD and Experimental Optimization of Formula SAE Race Car Cooling Air Duct.

Training. 2008, pp.08-14.

15. CARROLL, S. Tune to Win, Aero Publishers Inc., 1978, pp.97-107.

16. CHRISTOFFERSEN, L., SÖDERBLOM, D. and LÖFDAHL, L. Improving the Cooling Airflow of an

Open Wheeled Race Car. In: SAE Technical Paper 2008-01-2995, 2008.

Page | 33

17. KAMATH, S., DAMODARAN, V. et al., CFD and Experimental Optimization of Formula SAE

Race Car Cooling Air Duct. In: SAE Technical Paper 2013-01-0799, 2013.

18. MAHON, S.A. and ZHANG, X. Computational analysis of pressure and wake characteristics of

an aerofoil in ground effect. In: Journal of Fluids Engineering, 2005.

19. PITTS, A., HODGSON, S., BARRETT, J., WRIGHT, C., MEADOWS, T. FSAE Engine 2010/11.

School of Mechanical Engineering: University of Leeds, 2010.

20. SPAL Automotive, 12 volt suction fans [online]. 2013. [Accessed 5 December 2013].

Available from: http://www.spalautomotive.co.uk/acatalog/12_VOLT_SUCTION_FANS.html

21. LANFRIT, M. Best practice guidelines for handling. In: Automotive External Aerodynamics

with FLUENT, 2005.

22. BARDINA, J.E., HUANG, P.G. and COAKLEY, T.J. Turbulence Modelling Validation Testing and

Development. In: NASA Technical Memorandum 110446, 1997.

23. ANSYS Inc. Turbulence modelling In: ANSYS FLUENT 14.0 User’s Guide, 2011.

24. Engineering Toolbox, Aluminium thermal characteristics [online]. 2009. [Accessed 20

December 2013]. Available from: http://www.engineeringtoolbox.com/

25. MetOffice, Silverstone Motor Racing Circuit climate [online]. 2010. [Accessed 20 December

2013], Available from: http://www.metoffice.gov.uk/public/weather/climate/silverstone-

motor-racing-circuit-northamptonshire#?tab=climateTables

26. DIAMANT, N.S., Engine Cooling Systems and Radiator Characteristics. In: SAE Technical

Paper 240013, 1924.

27. KEATING, M. Accelerating CFD Solutions. In: ANSYS Advantage Volume V, Issue 1, 2011.

28. DE SILVA, C.M. Computation flow modelling of Formula-SAE sidepods for optimum radiator

heat management. In: Journal of Engineering Science and Technology, Vol. 6, No. 1, 2011.

29. Formula-E, Reveal of the Formula-E 2014 design [online]. 2013. [Accessed 20 April 2014],

Available from: http://www.fiaformulae.com/multimedia/

30. Exotic Cars At Formula Student Germany, Formula Student Team Weingarten [online].

2013. [Accessed 10 January 2014], Available from: http://www.coolage.in/photos/formula-

cars-designed-by-undergrad-students/#!slide=1023012

31. CROSS, B. Formula student bodywork design and manufacture. School of Mechanical

Engineering: University of Leeds, 2014.

Page | 34

Appendix A: Enclosure dimensions and boundary conditions

Figure 27: Detailed domain geometry for 3D analysis of a radiator within a side pod.

Page | 35

Appendix B: Radiator top mounting bracket drawing

Figure 28: Radiator top mounting bracket drawing.

Page | 36

Appendix C: Radiator bottom mounting bracket drawing

Figure 29: Radiator bottom mounting bracket drawing.

Page | 37

Appendix D: Side pod design final renderings on F15 Chassis Final 3D CAD Model renderings of side pod (flat plate on top to be removed) on a F15 Chassis.

Figure 30: Isometric view on 3D designed side pod model on F15 chassis.

Figure 31: Top view on 3D designed side pod model on F15 chassis.

Page | 38

Appendix E: Cooling system final assembly 3D CAD model renderings

Figure 32: Cooling system 3D CAD model (view from the back).

Figure 33: Cooling system 3D CAD model (view from the front).