automotive special report

Aer

odyn

amic

s &

Veh

icle

Th

erm

al M

anag

emen

t

Dedicated zone for your image

Up to your eyeballs in simulation data?

The 3DS logo, SIMULIA, and Abaqus are trademarks or registered trademarks of Dassault Systèmes or its subsidiaries. Other company, product, and service names may be trademarks or service marks of their respective owners. Copyright Dassault Systèmes, 2010.

Simulation Lifecycle Management from SIMULIA helps engineers and scientists organize and quickly find simulation data. SLM helps you document and automate best practices with tools that capture and reuse the intellectual property generated by simulation—which saves time, lowers costs, and maximizes return on investment.

SIMULIA is the Dassault Systèmes Brand for Realistic Simulation. We provide the Abaqus product suite for Unified Finite Element Analysis, Multiphysics solutions for insight into challenging engineering problems, and SIMULIA SLM for managing simulation data, processes, and intellectual property.

Learn more at: www.simulia.com

?

InTroducTIon

03 Vehicle Thermal Management

Introduction by Richard Johns

BrEAKInG nEWS

05 Aston Martin chooses STAr-ccM+ for Vehicle Aerodynamics

& Thermal Management

07 Toro rosso: STAr-ccM+ Gives You (More Aerodynamic) Wings

AErodYnAMIcS

09 Aerodynamics & Thermal Management of Vehicles

Reducing drag is a critical factor in improving fuel consumption

13 Track car Aerodynamics

Analyzing the effect of aerodynamic enhancements on a small hatchback

16 Seven Benefits

7 good reasons why you should be looking at STAR-CCM+

MoTorcYcLE

17 Simultaneous Evaluation on Aerodynamics & Air-cooling Performances

Motorcycles using CFD Analysis

WInd TunnEL

21 Improving the competitiveness of cFd

Simulations against wind tunnel tests

VEhIcLE ThErMAL MAnAGEMEnT

23 hot Stuff

Vehicle Thermal Management in STAR-CCM+

BATTErY

29 The World’s First Mass-Produced Electric Vehicle

CFD Simulation of Lean, Green & Frighteningly Mean Tesla Model S.

31 Modeling of Battery Systems & Installations for Automotive

Battery-powered vehicles

FuEL cELL

33 clean, Green & Frighteningly Fast

CD-adapco helps Ford break the land-speed record for fuel-cell powered cars

rAcInG

37 Simulate To understand

The 1973 Ferrari “Spazzaneve” [Snowplough]

41 Le Mans Prototype

Increasing Front Downforce

45 InG renault F1 Team Takes The Lead With STAr-ccM+

Formula One Aerodynamics

49 Formula for Success

Using STAR-CCM+ to design a 2009 Formula SAE race car

TrAInInG

52 Training courses

rESELLErS

Australia Veta Pty [email protected]

BrazilMulticorpos [email protected]

GreeceENEFEL [email protected]

Israel ADCOM [email protected]

new ZealandMatrix Applied Computing Ltd. [email protected]

russiaSAROV [email protected]

South AfricaAerotherm Computational Dynamics [email protected]

TurkeyA-Ztech Ltd [email protected]

china

CDAJ China Beijing • Shanghai [email protected]

Japan

CDAJ Japan Yokohama • Kobe [email protected]

AMErIcAS

united StatesHeadquarters CD-adapco • New York office 60 Broadhollow Road Melville, NY 11747, USA Tel.: (+1) 631 549 2300 [email protected] www.cd-adapco.com

Atlanta GA Austin TX Cincinnati OH Detroit MI Houston TX Lebanon NH Los Angeles CA Seattle WA State College PA Tulsa OK [email protected]

For S. America - please contact Melville Office

EuroPE

united KingdomHeadquarters CD-adapco • London office 200 Shepherds Bush Road London, W6 7NL, UK Tel.: (+44) 20 7471 6200 [email protected] www.cd-adapco.com

Aberdeen [email protected]

France: Lyon, [email protected]

Germany: Nü[email protected]

Italy: Rome, [email protected]

norway: [email protected]

ASIA-PAcIFIc

India: CD-adapco IndiaBangalore [email protected]

Japan: CDaEs Yokohama [email protected]

Korea: CD-adapco KoreaSeoul [email protected]

Singapore: CD-adapco SEAsia Singapore [email protected]

Global offices cd-adapco

EdITorIAL

Dynamics welcomes editorial from all users of CD-adapco software or services.

To submit an article: Email [email protected] Telephone: +44 (0)20 7471 6200

Editor Stephen Ferguson - [email protected] Editors Richard Johns - [email protected] Steve Hartridge - [email protected] Lauren Wright - [email protected] Art direction & design Brandon Botha - [email protected] Sales Geri Jackman - [email protected] Events Tara Firenze - [email protected] Events Marianne Müller - [email protected]

SuBScrIPTIonSDynamics is published approximately three times a year, and distributed internationally. To subscribe or unsubscribe, please email [email protected] Telephone +44 (0)207 471 6200

Media Kit available online at: http://www.cd-adapco.com/press_room

conTEnTS

29 33

05 07

09 17

21 23

37 41

45 49

..::InTroducTIon Richard Johns

vtm V T M S P E C I A L R E P O R T03

In the midst of constant media reminders about how tough times are, it’s dif ficult not to be at least a little gloomy about the prospects for the engineering business as a whole. This magazine is designed to provide an antidote to the doom and gloom showing that, not only is the CAE business as buoyant as ever, but that simulation is becoming even more per vasive, being used at ever y stage of the engineering process, and penetrating all levels of industr y.

Introduction by richard Johns

This magazine contains stories that demonstrate how CFD is being used for everything from student motorsport design to the historical analysis of long forgotten race cars, in each case demonstrating that serious engineering analysis can be performed using very limited resources.

Just a few years ago this would have been unthinkable. Serious vehicle aerodynamic simulation was the sole preserve of race-car manufacturers and OEMs, each of whom would employ large teams of dedicated specialists working a cluster of machines around the clock to churn out timely engineering data capable of positively influencing the vehicle design.

The innovation that is driving this trend is “automation”. At its simplest level automation provides a stress free path from geometry import to engineering simulation results. For generations of engineers, such as myself, who built careers and reputations on mastering the “blood, sweat and tears” approach to CFD (manually generating meshes for complex industrial geometries), this can seem a little disconcerting, however automation has good news here too.

The overriding goal of automation is to free engineers from the repetitive and mundane tasks associated with preparing and running simulations, allowing them to spend more time analyzing engineering results and generating a constant stream of information to guide the design process, ultimately resulting in more innovative, better engineered, products. Rather than focusing on just a few design points, engineers have the opportunity, for the first time, to simulate entire design spaces.

A good example of this is our cover story from Propulsive Wing LLC (pg 07)in which STAR-CCM+ was used to map the complex relationship between propulsion system settings and the aircraft stability - creating a stable aircraft design before the first prototype had been constructed. A thumb through these pages, or a visit to one of our upcoming webinars, seminars or STAR conferences should help to convince you that automation really is the future of Computer Aided Engineering, and that no company is better placed to provide you with the necessary tools than CD-adapco.

Finally, I’d like to draw your attention to the “No Engineer Left Behind” program, which offers free training and STAR-CCM+ licenses to Engineers that have recently lost their job as a result of the economic climate. If you know anyone in this position, please encourage them to participate in the program.

Richard JohnsAutomotive DirectorCD-adapco

i EMAIL: [email protected]

On it’s simplest level automation provides a stress free path from geometry import to engineering simulation results.

Vehicle Thermal Management

Vehicle Thermal Management

..::InTroducTIon Breaking News


An Aston Martin combines three important elements: power, beauty and soul, shaped through the ideas and vision of its designers and engineers who are united by a common goal and a common spirit: to build the most prestigious sports cars.

Dr Richard Johns, CD-adapco’s Director for the Automotive Industry is excited to be associated with one of the world’s most prestigious automotive marques: “Aston Martin has always been defined by the combination of creativity and manufacturing discipline. STAR-CCM+, through its automated simulation process, allows design engineers to rapidly explore entire design spaces, providing technical insight and generating creative enthusiasm.” <

Aston Martin Chooses STAR-CCM+ for Vehicle Aerodynamics & Thermal ManagementPrESS rELEASE: New York & London, April 15, 2009

i MORE INFORMATION VISIT http://solutions.cd-adapco.com/automotive

An Aston Martin combines three important elements: Power, Beauty & Soul. Aston Martins are truly special - they always have been & always will be.DR ULRICH BEZ, CHIEF EXECUTIVE OFFICER, ASTON MARTIN

CD-adapco is pleased to announce that Aston Mar tin, the British manufacturer of prestige luxur y spor ts cars, will use STAR-CCM+, CD-adapco’s technology leading CFD simulation tool, for the simulation of aerodynamics and vehicle thermal management.


vtm V T M S P E C I A L R E P O R T 06



Toro Rosso: STAR-CCM+ Gives You (More Aerodynamic) Wings

CD-adapco is pleased to announce that, after extensive evaluation, Italian Formula One Team Scuderia Toro Rosso has chosen STAR-CCM+ as their simulation tool for the aerodynamic design of their racing cars.

PrESS rELEASE: New York, London and Faenza, June 8, 2009

i MORE INFORMATION VISIT http://www.cd-adapco.com/press_room/2009/06-08-tororosso.html



Since their Formula one debut in 2006, Scuderia Toro Rosso have proved themselves one of the brightest new teams in Formula One, scoring a maiden victory in the 2008 Italian GP, on the way to securing sixth place overall in the 2008 Constructor’s Championship. One of the principal aims of the team is to discover and nurture new driving talent through their Young Driver Program, the most successful graduate of which is German driver Sebastian Vettel who became the youngest driver ever to win a Grand Prix in his two successful years with the team.

Until the 2009 season, Toro Rosso cars were designed by Red Bull Technology, however a move to more independence from their sister team facilitated the need for greater on-site CFD capability at the team’s Faenza base. After benchmarking a number of different CFD software products, Scuderia Toro Rosso adopted the STAR-CCM+ solution. Ing. Nicolò Petrucci, head of aerodynamics for Scuderia Toro Rosso explains:

“Formula 1 has always been the pinnacle of automotive technological development, throughout the year we are constantly working to squeeze more performance out the car and to do this we need the best engineers and the best tools. Having reviewed the available options, it was obvious that STAR-CCM+ represented the best solution on the market.”

“We chose STAR-CCM+, not only because of CD-adapco’s pedigree in the automotive sector, but also due to the innovative and advanced nature of the tool. STAR-CCM+’s automated meshing technology really is second to none and the speed at which we could mesh and analyze new designs was a revelation. The software is extremely easy to use with an intuitive user interface, quite a change from when I first saw CFD in F1 in 1989!”

CD-adapco is the leading supplier of Computational Fluid Dynamics software to Formula One. For the 2009 season, almost every car on the Formula One grid is designed using either STAR-CCM+ for aerodynamics and thermal management, or STAR-CD for engine simulation. CD-adapco’s director for the automotive industry, Dr. Richard Johns explains:

“Scuderia Toro Rosso have demonstrated the fact that STAR-CCM+ is the aerodynamic code of choice for the Formula One grid. In an industry where speed is king in every sense, STAR-CCM+ uniquely allows teams to significantly reduce analysis turnaround time, through the automatic preparation and meshing of car geometries, without any sacrifice in accuracy. The unique STAR-CCM+ power session license, allows our users access to an unlimited number of processors for modest cost” <

At first, we decided to make a few parts in our own composites department, but for the first time ever, we have now made the actual chassis in-house, whereas last year it was produced by Carbotec in Austria. GIANFRANCO FANTUZZI - TEAM MANAGER

..::FEATurE ArTIcLE Aerodynamics


Although aerodynamic optimization was initially focused on reducing drag, mainly for increased high-speed per formance, today’s interests are much broader. Reducing drag is a critical factor in improving fuel consumption (or range in the case of electric vehicles) and this is one of the key buying criteria for a number of disparate vehicle classes from trucks, where the fuel is the single highest component in operating cost, through to the mass-market of the more humble family saloon. In the per formance and racing car arena drag reduction is vital, but equally impor tant is the generation of high levels of downforce and good car balance.

dr richard Johns, Automotive director, cd-adapco.

Aerodynamics & Thermal Management of Vehicles

u RIGHT Streamlines showing the improved heat exchange of both radiators, thanks to the good quality of air flowing through them.

one of the key factors in determining the levels of fidelity possible in aerodynamic analyses is the processing power available. In recent years, a sharp decline in computer cost, coupled with ever more powerful processors has enabled simulation complexity to increase considerably. Multi-vehicle scenarios are now becoming increasingly important, whether this is the close-proximity drafting in NASCAR races or truck~car interactions in high speed overtaking maneuvers.

Another by-product of increased HPC capacity is the study of unsteady aerodynamics and effects such as aeroacoustics. Wind-generated noise is both obtrusive and tiring to the driver and passengers and can take various different forms. Broadband noise is produced by the pressure fluctuations arising from the turbulence generated by the flow around obstacles, such as wing mirrors or the “hiss” that can be heard around the A-pillar region of some vehicles. Another, and quite different characteristic, is narrow-band noise. This can range from a high-frequency whistle to a low-frequency booming and is the result of a

volume, such as the passenger compartment, acting as a helmholz resonator when exposed to the airstream, for example by an open sunroof or a partially-open window.

Heat management has also become a critical design issue in recent years. Higher engine specific power, packaging constraints, temperature-sensitive electronics, aftertreatment devices with exothermic reactions, brake cooling and, more recently, lithium-ion batteries in hybrid and plugin hybrid electric vehicles (HEVs & PHEVs) and their associated stringent thermal management and safety requirements dictate that a holistic approach is applied early in the vehicle layout design to avoid expensive late reworking and post sale recalls.

Last, but not least, the safety and comfort of the driver and passengers cannot be forgotten; ensuring that windscreens de-ice and de-fog and producing a comfortable environment throughout the passenger compartment under all ambient conditions is a major challenge to the interior designer. g



•••• BONNET TEMP 20oc - 79oF

••••WINDSCREEN TEMP 16oc - 73oF

••••WIND SPEED 50m/s

••••PRESSURE 16KPa

••••TERRAIN GRADIENT +13o



In recent years, CFD has “come of age” in the automotive industry to the extent that ALL of the above phenomena are calculable from design data and the majority of OEMs and major suppliers routinely apply these analyses in the vehicle design process. The increased deployment of simulation in the design and analysis process has been driven by a number of factors chief among which is the drive to reduce development costs. Building accurate prototypes for wind tunnel and thermal testing can be extremely expensive so “virtual prototyping” becomes increasingly attractive.

CD-adapco has been actively engaged with the automotive industry for almost 30 years and, during this time, has developed engineering solutions to all of the issues mentioned above. One very important aspect of these solutions is, of course, to understand the relevant physics and to develop appropriate modeling that properly reflects the underlying phenomena and that is embodied in software using robust and efficient numerical methods. That, in itself, is not sufficient, however; to enable a robust, fast, repeatable and cost-effective processes to be established other factors must be considered.

It is important where and how the analysis is to be incorporated into the engineering process; this, in turn drives the data requirements and the level of fidelity of the result. For example, is detailed CAD data or simpler concept design data available? What is the format and completeness of the data? Is the data parameterized to be used for automated optimization? Is the geometry data “clean” or “dirty” (holes, gaps, self-intersections, overlaps etc). How will design iterations be carried out? All of these scenarios can and do exist and it is vital that the analysis process is able to integrate seamlessly with whatever is available. STAR-CCM+ provides all of the tools necessary to accomplish this and to align the analysis and engineering processes.

Above all else, the analysis engineer must be successful, this means that results of sufficient accuracy must be delivered on time to enable design decisions to be made; if this is not fulfilled, then analysis becomes, at best, irrelevant to the decision-making process and, at worst, delays the design.

Just as the design of a new automobile requires a holistic approach, so too does the development of the CAE software used. CD-adapco recognizes that analysis software has never, and will never, be an “off the shelf” product and user interaction is vital in the way in which their products are developed and supported. As important as the quality of the software itself, is the quality of the team behind it and the services they provide, with dedicated support engineers (not just call centers) and customized training through to engineering services team around the globe.

As well as helping users deploy their software effectively, the support teams also feedback customer requirements to the development side of the organi-zation, a feature reflected in the evolution of STAR-CCM+ in which almost all new

developments are customer driven. An example of this is seen in the June 2009 release of STAR-CCM+, version 4.04, which had over 100 customer requested enhancements and more than 220 individual development tasks.

Throughout its history, the automotive industry has constantly evolved as new technology has been developed and the demands of the end user have changed. As vehicle development has progressed so too have the capabilities of the analysis software used to drive development with CD-adapco at the forefront of this innovation. Features such as STAR-CCM+’s surface wrapping technology and power session licensing (allowing unlimited processors at a fixed cost) reduce simulation turnaround time so helping engineers produce highly optimized designs that meet the needs of the increasingly demanding marketplace.

It is becoming increasingly clear that, as we progress into the 21st century, a seismic shift is occurring in the way that automobiles are developed with sustainability at the forefront of everyone’s minds. Electric vehicles are no longer the realm of science fiction with all the major automotive manufactures investing in this new technology. As the automotive industry changes its focus, so too do the demands on analysis software suppliers. It should come as no surprise that CD-adapco is rising to meet these challenges and is, as always, at the forefront of CAE innovation. <

i MORE INFORMATION VISIT OUR AUTOMOTIVE RESOURCE http://www.cd-adapco.com/auto

Above all else, the analysis engineer must be successful, this means that results of sufficient accuracy must be delivered on time to enable design decisions to be made; if this is not fulfilled, then analysis becomes, at best, irrelevant to the decision-making process and, at worst, delays the design.

u RIGHT Streamlines showing the improved heat exchange of both radiators, thanks to the good quality of air flowing through them.



Track car Aerodynamics

q BELOWThe modified car in the VZLU open section wind tunnel.

q BELOWExperimental wind tunnel results were compared to computational models.

Stepan Zdbinsky, Aeronautical research and Test Insititue, czech republic.



Fans of motorspor t increasingly want to get a taste of what it feels like to go bumper to bumper with other race cars in a competitive environment. While the dream of owning a top spor ts car might be beyond the reach of the average armchair racer, an increasing number of companies of fer the general public a chance to feel the adrenalin a high power car and a strip of tarmac brings, allowing clients to tr y out a days racing without having to invest large sums of money.

There is little doubt that a single seat race car offers the ultimate racing experience. Unfortunately the skills required to control such a vehicle combined with the costs to design and maintain one means that single seaters are outside of the comfort zone for most racers. For many aspiritional racing drivers modified road cars

present a more sensible introduction to the world of racing. The Aeronautical Research and Test Institute (VZLU) in Prague was asked to analyze the effect of aerodynamic enhancements on a small hatchback. Such a car represents the ideal introduction to track racing with a good balance of speed and handling with two seats allowing an instructor to accompany the driver.

The geometry The geometry of the car was created using 3D laser scanning to accurately reproduce the complete configuration of the vehicle including three major additional modifications to the standard car:

1. An enhanced underbody and rear diffuser 2. A two element rear wing 3. A modified front bumper incorporating a splitter. The scanned geometry was read into STAR-CCM+ and split along the symmetry plane so a half model could be analyzed. The surface was then prepared using the surface wrapper and re-meshed before a 10 million cell trimmed mesh was generated.

As well as simulating the full size car, a 1/4 scale model was also created for the purpose of direct comparison with wind tunnel tests that will be carried out in the future. This model will be analyzed in a circular open test section low speed wind tunnel, therefore the tunnel geometry immediately upstream and downstream of the test section was also incorporated into the computational domain.

Analysis The aerodynamic modifications, mentioned previously, were designed to improve the handling of the car, specifically its stability through corners, an essential criteria when novice drivers are learning to race. To achieve this, additional downforce is required as well as (if possible) a reduction in the overall drag of the vehicle. g

p ABOVEStreamlines and pressure contours on the modified car.



i FOR MORE INFORMATION VISIT: http://www.vzlu.cz

p ABOVETotal pressure contours of the car in the wind tunnel.

Výzkumný a zkušební letecký ústav (VZLu)VZLÚ was founded in 1922 as the Institute for Air Navigation Studies under the auspices of the Ministry of Defence. More than 80 different

types of Czechoslovak aircraft have passed through the Institute’s labs to date.

Customers from turbo-machinery, car industry, civil engineering and many other industrial branches place their orders for developmental and

testing work with VZLÚ. Since 1993 the Institute has been working on R&D programmes tendered by ministries of the Czech Republic and

since 1999 on programmes in aeronautics supported by the European Union.

As well as providing computational analysis services, VZLU has a range of test facilities including 4 low speed and 10 trans/super sonic

wind tunnels.

The underside modifications and the front splitter addition are designed to reduce drag and increase downforce. Above the front splitter the air dam has the effect of raising the pressure which, combined with the reduced pressure of air accelerated below it, increases the downforce on the front of the car. By ensuring the underbody of the car is a “smooth” as possible not only is drag reduced but downforce increased through a stronger ground effect. The splitter also has the added advantage of increasing the airflow through the front heat exchangers, helping the engine to perform better.

The rear diffuser, fitted in combination with the smoothed underbody, has the opposite effect to the splitter and works to bring the low pressure high velocity air underneath the car back to ambient conditions without inducing extraneous turbulence. If effectively fitted, this will help make the car underbody a more effective downforce generating device while reducing overall drag.

The car studied is a rear wheel drive vehicle, so the addition of a rear wing fitted to the roof of the car, is intended to significantly increase downforce. This has the effect of increasing the stability and drivability of the car through corners as well as improving the ability of the car to transfer power through the rear wheels onto the track.

Effect of aerodynamic modifications Analysis showed that the front splitter has the desired effect, creating a stagnation point and reducing the pressure underneath the car. This, combined with the smoother underbody and rear diffuser, reduces the drag on the vehicle by around 10% while simultaneously increasing the lift by 840N at 230km/h.

The rear wing, placed slightly backwards and below the roof line, delivers a considerable increase in downforce raising it by 1890N at 230 km/h, this gain does come at a price, however, as drag is also increased by 6%. Given the critical nature of rear end grip to the handling of the vehicle, the elevated drag is a price worth paying especially as savings have been made elsewhere with the underbody modifications.

conclusions STAR-CCM+ has helped VZLU study the race modification of road cars to a level of detail not previously possible. Key to the success of the project was the ability to effectively and rapidly mesh a complex aerodynamic body to an acceptable level of accuracy. As the project continues a full analysis of the accuracy will be conducted comparing the computational simulation to wind tunnel tests carried out at the VZLU facilities. <

p ABOVEAutomatic surface wrapping and hexahedral meshing was used to generate the model.

..::FEATurE ArTIcLE Automotive


i FOR MORE INFORMATION VISIT THE NEW VEHICLE SIMULATION RESOURCE CENTER http://solutions.cd-adapco.com

The Seven Benefits2009 was a tough year for the auto industr y and 2010 is likely to be even tougher if economic predictions prove to be correct. Without exception, auto companies and suppliers are looking harder than ever to improve productivity and cost ef fectiveness in their product development processes.

cd-adapco is part of the auto industry and has been a significant provider of CAE software and services to the OEMs and their suppliers since 1980. In the early part of the new millennium CD-adapco embarked upon the development of a major new software package, STAR-CCM+, for computational modeling of problems in continuum mechanics. STAR-CCM+ was first released in 2005 and has since matured into the most powerful software available for modeling vehicle aerodynamics and thermal management (VTM) and addresses the issues that are considered to be of the greatest importance to product development orga-nizations. If you work in such an organization and are responsible for delivering aero or thermal solutions, then please consider the 7 good reasons below why you should be looking at STAR-CCM+ if you are not already doing so.Accuracy is of primary importance in decision making and especially when opti-mum solutions are sought in a competitive marketplace. STAR-CCM+ embodies state-of-the-art models and numerics to deliver accurate aerodynamics and VTM solutions for both steady and unsteady simulations to ensure that you make the correct decisions.Breadth of capabilities is critical to deliver a complete solution for all problems. The accepted industry-standard turbulence models - LES/DES, k-omega SST, Langtry-Menter together with sub-models for fans, heat-exchangers, radiation, conjugate heat transfer, aeroacoustics and much more all come as standard in STAR-CCM+.consistency of results is achieved by using a customizable pipeline process, from CAD to Results, which integrates STAR-CCM+ into your organization. Once

the process and pipeline has been defined for your requirements, it may be executed repeatedly for both new designs and design iterations to deliver con-sistent results whoever and wherever the process is executed. A powerful suite of pre and post-processing tools within STAR-CCM+ ensures consistency of the total process.robustness of every aspect of the process ensures that results will be delivered on time, every time, so that decision points are met and product development proceeds on schedule.Speed to deliver results is being constantly squeezed as product delivery tim-escales get ever shorter. The automated pipeline execution, fast steady-state and transient solvers for both aerodynamics and thermal solutions coupled to outstanding parallel performance of STAR-CCM+ delivers results in the mini-mum time possible.Support from CD-adapco’s global organization provides specialist training, men-toring and a dedicated support engineer, no matter where you are in the world, to ensure that your team is successful.Value of services is extremely important at all times, but especially in today’s tough economic environment. This is why CD-adapco delivers all of the above in one competitively priced product, STAR-CCM+, there are no hidden extras.If your organization uses or is considering using aerodynamics or thermal analy-sis and is not using STAR-CCM+ already, then contact us today!

For more information visit: www.cd-adapco.com/auto

pEpsilon Euskadi & METCA using STAR-CCM+ www.epsiloneuskadi.com

❐ FACTS

Boasting an all-new compact engine, shorter wheelbase and new styling, the new

GSX-R1000 raises the bar once more in the hotly-contested Supersport class.

With significant changes in the engine department, the new GSX-R boasts a more

over-square bore and stroke, larger, titanium valves, a higher compression ratio, and 12

hole fuel injectors, to deliver a finer fuel mist for more complete combustion. All this with a

power-plant that is 59mm shorter from front to rear.

And it’s not just the engine that’s seen the significant changes either, as the all-new chassis

makes the GSX-R1000 more agile than ever before.

With a unique engine and chassis package, the aggressive aesthetics and rider controls

top-off the flagship GSX-R. With the unique Suzuki Advanced Exhaust System, featuring

low-slung MotoGP inspired titanium exhausts, a lighter, sculptured fuel tank, on-board lap

timer and revised Suzuki Drive Mode Selector controls, the new bike offers the complete

sports package.

In the development of a spor ts motorcycle, a balance must be achieved between low drag to improve per formance and good air flow through the cooling system to maintain reasonable fuel economy. Typically, however, a low drag coef ficient (CD) and increased flow through the heat exchangers are contradictor y in nature, as an improvement in one leads to deterioration in the other. With this in mind, Suzuki looked to STAR-CCM+ to help optimize their bike designs by studying aerodynamics and heat exchanger flow simultaneously.

To develop a set of best practices for further analyses, the influence of turbulence models and mesh density on bike performance was carried out. The results of the CFD were then compared to wind tunnel tests to verify their accuracy using a test vehicle.

computational & Experimental Methods Two different mesh sizes were evaluated for the current study, both consisting predominantly of hexahedral (trimmed) cells with polyhedral cells used in the heat exchangers. Both meshes were generated automatically using STAR-CCM+ with volumetric refinements used to better capture flow structures around the bike in general and through the heat exchanges specifically. The resulting coarse mesh consisted of approximately 17 million cells with the

finer grid (figure xxx) having around 24 million. As well as evaluating these two different meshes, the k-ε realizable and k-ω SST turbulence models were also studied.

Key to the successful, and accurate, analysis of vehicle external aerody-namics (of any configuration) is a suitably sized computational domain. In the simulations carried out in the current study a rectangular domain was placed around the bike 8 times the width, 5 times the height and 6 times the length of the bike, so ensuring the boundaries had no detrimental effect on the flowfield near the motorbike. With the external boundaries in place a blockage ratio of just 1.6% was achieved

In order to evaluate the accuracy of computational results, velocity of the flow passing through the heat exchangers and values of CD are g

..::FEATurE ArTIcLE Motorcycle


Suzuki GSX-R1000 2009

Yoshihiko Sunayama, Ph.d - Group Leader, cAE Group, digital Engineering dept.Suzuki Motor corporation

Simultaneous Evaluation onAerodynamics & Air-coolingPerformances for Motorcycleusing cFd Analysis

i MORE INFORMATION ON SUZUKI GSX-R1000 2009: http://www.suzuki-gb.co.uk/bike/gsxr1000k9/tech/



❐ FA

CTS

dIM

EnSIo

nS &

WEI

Gh

TS

Ove

rall

leng

th:

2045m

m (8

0.5

in)

Ove

rall

wid

th:

710m

m (2

8in

)

Ove

rall

heig

ht:

1130m

m (4

4.5

in)

Whe

elba

se:

1405m

m (5

5.3

in)

Sea

t hei

ght:

810m

m (3

1.9

in)

Ker

b M

ass:

203kg

(447.5

lbs)

Fuel

cap

acity

: 17.5

litre

s (3

.8 U

K g

allo

ns)

EnG

InE

SPEc

IFIc

ATIo

nS

Engi

ne c

apac

ity:

999cc

Engi

ne:

Four

strok

e, li

quid

-coo

led,

DO

HC

Bor

e:

74.5

mm

x 5

7.3

mm

Com

pres

sion

ratio

: 12.8

: 1

Lubr

icat

ion:

W

et s

ump

Igni

tion:

El

ectron

ic ig

nitio

n (T

rans

isto

rised

)

Fuel

sys

tem

: Fu

el in

ject

ion

Sta

rter

: El

ectric

Tran

smis

sion

: 6-s

peed

con

stan

t mes

h

Driv

e:

Cha

in

ch

ASSIS

SPEc

IFIc

ATIo

n

Fron

t sus

pens

ion:

In

vert

ed te

lesc

opic

, coi

l spr

ing,

spr

ing

pr

eloa

d fu

lly a

djus

tabl

e, reb

ound

and

co

mpr

essi

on d

ampi

ng fo

rce

fully

adj

usta

ble

Rea

r sus

pens

ion:

Li

nk ty

pe, o

il da

mpe

d, c

oil s

prin

g, s

prin

g

pr

eloa

d fu

lly a

djus

tabl

e, reb

ound

and

co

mpr

essi

on d

ampi

ng fo

rce

fully

adj

usta

ble

Fron

t bra

kes:

Rad

ial m

ount

, 4-p

isto

n ca

liper

s, 3

10 m

m

di

sc, t

win

Rea

r bra

kes:

1-p

isto

n ca

liper

, 220m

m d

isc

Fron

t tyr

es:

120/7

0 Z

R17M

/C (5

8W

) tub

eles

s

Rea

r tyr

es:

190/5

0 Z

R17M

/C (7

3W

) tub

eles

s

Su

Zu

KI G

SX

-r1000 2

009 S

PEc

IFIc

ATIo

nS

creativity- a human gift to develop products that promote better living conditions and satisfy people’s need. Since the founding of

Suzuki Motor Corporation, we have always pursued providing ‘value-packed products’ as one of our manufacturing philosophies.

Realizing that the value differs according to the times,country and lifestyle,we are fully determined to challenge for the creativity

to make such products for customers around the world with our advanced technologies and enthusiasm.



studied in the wind tunnel. Vane-type anemometers are attached at 16 points on the back face of the radiator to obtain the mean velocity of flow.

drag analysis The comparison of experimental and the computational results of CD are shown in Fig. xxx. Case 1 and 2 are the results of the SST k-ω model with the mesh type A (fine) and B (coarse), respectively, case 3 and 4 are the results of the realizable k-ε model with the mesh type A and B, respectively. Across all mesh/turbulence model comparisons, the maximum difference between the experimental and the computational results is 2.9%.

When comparing turbulence models on the same mesh, the values of CD for the SST k-ω are 0.017 to 0.019 higher than those of the realizable k-ε model. If the turbulence model is fixed, comparing the two meshes shows that the values of CD for the finer mesh are 0.010 to 0.012 greater than those of the coarse mesh.

The breakdown of total drag force for each part of the test vehicle in Case 1 is shown. It is seen that the drag force on the cowling is biggest contributor to overall vehicle drag with approximately a quarter of the total. The radiator is seen to produce the second highest component drag on the bike with 13.4% of the total, hence the need to optimize radiator flow minimizing drag while maintaining cooling performance.

From these results it is seen that CFD produces a more than acceptable accuracy when compared with experiment, and that with an adequately fine mesh and the correct choice of turbulence model STAR-CCM+ may be used as a design tool for future bike design. radiator flow Experimental and computational mean velocity flow through the radiator is shown. It is seen that for all combinations of mesh and turbulence model, velocities are overpredicted by between 8.1 to 16.8 percent compared to

(a) C1 C2 C3 C4

R1 1.42 1.00 1.02 1.11

R2 1.16 0.83 0.98 0.99

R3 0.89 0.99 0.91 0.86

R4 1.24 1.66 1.45 1.29

(b) C1 C2 C3 C4

R1 1.34 0.96 1.07 1.14

R2 1.34 0.99 0.91 1.19

R3 0.99 1.22 1.27 1.12

R4 1.26 1.43 1.71 1.43

Table 1 Velocity distribution of flow passing through radiator in (a) Case 1 and (b) Case 3, normalized by experimental velocity.



experiment. When comparing turbulence models better agreement with experiment results is seen using k-ω SST model, although result quality is shows greater mesh dependence than with k-ε.

To study the velocity distribution of flow passing through the radiator, the results of computational velocity, normalized by experiment, at each measurement point is shown in Table 1. It can be seen that the best agreement with experiment, for both case 1 & 3, is seen in the upper central region of the radiator at points C2 & C3. The flowfield around the central section of the test vehicle can be seen in Figure xxx, with pressure contours also displayed. The areas where CFD compares well to experiment corresponds to high velocities where the bulk flow goes straight through the radiator, between the front forks, tire and cowling.

This good agreement in the higher velocity areas of the radiator is likely due to the comparatively simple nature of the flowfield, the flow in the other areas of the radiator is relatively complicated; shear flow from the front forks and flow almost parallel the frontal surface of the radiator. With this in mind, future work is needed to improve the capability of prediction of radiator velocities in these areas.

conclusion In order to evaluate both of aerodynamics and air-cooling performance for a motorcycle in a single calculation, a set of best practices has had to be developed and validated. The conclusions obtained from these studies are:

• From the small difference under 3% between the computational and the experimental results of CD, this simulation method can be practical for drag evaluation of a motorcycle. • From the difference of under 10% between the computational and the experimental results of mean velocity of flow passing through the radiator, this simulation method can be practical for evaluation of air-cooling performance of a motorcycle. On the other hand, these results show there is scope to improve the accuracy also. • The SST k-ω turbulence model with high mesh density of a computational model has better accuracy of prediction compared with the realizable k-ε turbulence model. Also, the sensitivity of mesh density for computational results in the SST k-ω turbulence model can be larger than that of the realizable k-ε turbulence model. <

Applus+ IDIADA, as a global par tner to the automotive industr y, suppor ts clients in their product development activities by providing design, engineering, testing and homologation ser vices to fit their needs. Its success in product development is built on the combination of highly experienced and motivated engineers as well as best-in-class test and development facilities, client focus and the constant drive towards innovation.

..::FEATurE ArTIcLE CFD vs. Wind Tunnel


L’Albornar Proving GroundHigh-speed Circuit

External Noise Test Track

Dynamic platform ‘A’

Dynamic platform ‘B’

Handling Track

General Road Circuit

Accelerated Fatigue Track

Test Hills

Straight Line Braking Surfaces

Comfort Track

Comfort Surfaces

Client Workshops

Off Road Track

Wet Handling Track

Total Area: 370 Hectares

A team of 900 engineers, from over 25 countries, as well as an international network of subsidiaries and branch offices in 15 countries ensure clients receive fast and customized services.

Applus+ IDIADA is present in Spain, France, Germany, Italy, UK, Luxembourg, Czech Republic, Poland, Japan, Korea, Malaysia, China, Taiwan, India and Brazil.

The thermal analysis of car engine bays is regularly carried out by IDIADA’s simulation department. In recent years, the IDIADA CFD team has performed several projects where the temperatures of elements of the engine bay were simulated in some cases, however, these projects became a challenge for IDIADA’s engineers with the geometric complexity of the engine bay and the advanced physics required to simulate it leading to projects that should have taken weeks ended up taking months. Project turnaround times of this length were clearly impractical so IDIADA implemented a research project called “Virtual Climatic Wind Tunnel” (VCWT) the aim of which was to optimize the simulation process while making it much more robust.

The ultimate goal of the VCWT project was to develop a tool that would simulate and be comparable with physical testing in terms of time, cost and accuracy. The VCWT project took 18 months, and after a study of the state of the art, a robust simulation process was designed, software suitable for each phase of the process selected and finally the simulation process automated.

Following criteria of the accuracy of the results ease of automation and ease of integration, STAR-CCM+ and RadTherm were selected for the CFD and thermal simulation respectively.

Automating the cFd simulations Thanks to the ease of use of STAR-CCM+, and the ability to write Java macros, a completely automated process could be implemented which performs: the setup and generation of the mesh, the physics and boundary condition specification, batch running of the simulation and generation of result reports. This new automatic process reads in two files, one containing the geometry to be analyzed, and one the physics of the problem (boundary conditions, physics models etc), before generating the CFD results without any intervention by the user.

The VCWT takes into account all the models required for the simulation of engine bays including: fans, porous media, heat exchangers, rotation of the wheels and rolling ground. The VCWT identifies the names of the parts, the type of boundary condition, the group it belongs to and the size of mesh along with any other relevant parameters, and generates a macro that performs the entire CFD process automatically.

The rest of the data needed to assign the simulation physics, test speed, porosity, heat transfer tables, etc., are read in through a text file. In this way, it is possible to configure as many set-ups as needed and carry out a design of experiments. In addition, this procedure was combined with a process of parameterized morphing and, within the same process it is possible to generate as many meshes as are needed. Given that the morphing is parameterized, it is possible to do an optimization of the shape of the model varying the morphing parameter.

coupling STAr-ccM+ to radTherm To calculate temperatures of the engine bay, the thermal analysis code, RadTherm is coupled to STAR-CCM+. This process is also automated, with an algorithm generated to exchange the values of temperature of the engine parts, ambient air as well as convection coefficients, between the two codes and solve iteratively.

Once the methodology for stationary simulations of the engine bay temper-atures had been implemented, the results were validated through testing on IDIADA’s proving ground and the accuracy of the results verified.

conclusions Within the framework of the VCWT project a simulation methodology has been developed that allows the entire CFD simulation process of engine bay cases to be carried out automatically and in batch. The main advantage of this new VCWT method is its robustness, meaning that the time required to perform the simulations is highly controlled and therefore has little variation. In addition, the automation of the simulation process has meant a time saving of more than 75% compared to manual methods. <

i TO CLAIM YOUR CALENDAR VISIT: www.idiada.com/

..::FEATurE ArTIcLE CFD vs. Wind Tunnel


Improving the competitiveness of cFd simulations against wind tunnel tests office of naval research, uSA.

dejan Matic, Bill clark, Ganesh Venkatesan, cd-adapco.

Since the first Model T rolled of f the famous Ford production lines, the issue of engine cooling has been of prime concern to vehicle designers. Putting an internal combustion engine inside a confined space will always provide a stern engineering challenge, as the explosive combustion of the fuel used to drive the vehicle releases energy not only in its kinetic form but, by the nature of the process, as heat. Ensuring this thermal energy is dissipated in a way that will not harm the components “under the hood” is essential to ensure that your expensive new shiny new automobile makes it beyond the car lot exit!

Vehicle Thermal Management in STAr-ccM+ John Mannisto & Joel davison, cd-adapco

❐ FACTS

For the past twenty-five years leading automotive companies have relied

on CD-adapco’s state-of-the-art technology to improve their designs.

STAR-CCM+, STAR-CD and the STAR-CAD Series provide engineers with an

advanced and complete CFD toolkit. This unique approach brings unrivalled

ease-of-use and automation to CAD preparation, meshing, model set-up

and iterative design studies, enabling engineers to deliver better results,

faster.

CD-adapco’s automotive team have pioneered many new application areas

as diverse as brake cooling and crankcase analysis. The company has

delivered CFD and FEA projects to all the top automotive companies world

wide. New product releases, on going training and educational programs

are helping customers keep pace with the evolving automotive industry.

..::FEATurE ArTIcLE VTM


STAR-CCM+ has been used extensively to provide insight into cooling performance and engine compartment flow. Up until recently is was common to take these results and use FEA methods to determine component temperatures, often requiring stand-alone radiation

plug-ins and fluid structure interaction software. The introduction of STAR-CCM+ has changed this, with CD-adapco’s engineering services team as well as a growing number of industrial users experiencing the benefit of the integrated, automated technology.

A typical scenario where STAR-CCM+ simulation can deliver tangible benefits is in the analysis of components failing post-production, for example: A new controller box is installed on a firewall or truck rail, and although testing was performed to ensure adequate cooling, warranty claims begin to surface six months into product release. At this point, the damage is done; production is in full swing, months of production inventory are operating in the field, and the process of determining the corrective action has only just begun.

Cases such as these, often handled by CD-adapco’s Engineering Services team, demonstrate the need for timely and accurate temperature prediction of the underhood environment – in the design loop - before the failures start to appear.

In a complex environment such as an underhood, there are numerous design developments running simultaneously. For example, modifications to the emissions system (i.e. turbo, EGR coolers, piping) may trigger corresponding changes to the fuel controller, and possibly changes to the packaging. Because

the changes to the design are being developed concurrently, it is not difficult to invision a scenario where, for example, an electronic component is mounted in an area that will be exposed to a re-routed exhaust pipe, Another example is the new DPF/SCR/Urea systems being used on trucks which are extremely large, and get very hot (especially during the regeneration phase). Locating these units to minimize interaction with other components (including vehicle occupants) is a challenge that requires so many factors that it is simply not practical to use traditional build/test/fail methods for optimizing their location.

The Sky is The Limit The technology applied to the analysis of automotive underhood environments can be extended to any situation where the accurate prediction of thermal fields is of vital importance.In passenger jets, flow under the floor, cockpit and passenger areas is integrally linked. Thermal behavior will depend on a multitude of factors, from the power output of the electronics to the conductivity of the carpet. Cooling requirements for the avionics have to be balanced with the pilot/passenger comfort requirements, icing issues in fuel lines need to be addressed and Boat-end APU’s and “boiler room” electronics can interact unpredictably. Simulating both the flow and thermal behavior of these complex environments can identify the issues earlier in the design, while there is still some flexibility in the packaging.

The methodology may also be applied to static objects such as a “GENSET”. By coupling an engine to an electric generator, these GENerator SETs can g





provide portable, compact electric power to remote locations such as construction sites or a military field camps. Reliability of these units is a premium requirement, and the environmental conditions can vary from a desert battleground to an arctic drilling site. Anticipating the thermal behavior of these systems in environmental extremes is something easily modeled using CFD and reduces the need for costly and time consuming environmental chamber testing.

The use of STAR-CCM+ is not restricted to terrestrial objects either with the thermal performance of satellites also extremely important. The thermal loads generated by electronics systems can be combined with radiation heat transfer not only internally but due to the extreme solar loads experienced outside of our atmosphere. To develop an understanding of the cooling requirements for this harsh environment, heat generation is applied down at the chip level, to accurately characterize the temperature distribution at the board level.

Clearly, the vehicle thermal simulation is extremely important, regardless of vehicle type, and the Engineering Services Team at CD-adapco saw this type of simulation as an important service opportunity. We outlined our goals, established methods, and the choice of software was obvious: STAR-CCM+

Our goal is a virtual vehicle that can provide overall thermal assessment, as well as sub-system or component thermal studies. The methods needed to achieve this have to be accurate, flexible and of a short enough turnaround time to stay within the design loop. There are two primary methods for combining underhood and thermal prediction, each offering different advantages:

A full conjugate model can provide the best characterization of the fluid/solid thermal interaction but requires a high quality CAD model and large amounts of computer power.

The explicitly coupled models offers the advantage of simpler modeling requirements, and the ability to work both

flow and solids models independently. This also results in two models with more manageable sizes, although the coordination effort between models now increases.

We have found application for both methods. The choice is influenced by the client, and includes several factors: computing resource, quality of CAD, even organization of engineering teams.

Since the temperature prediction work has traditionally been performed by the “thermal/stress” groups, it has often been done using FEA methods. At CD-adapco, the Thermal-Stress Engineering team has traditionally used this technology but the recent advances in finite volume stress and automated CAD preparation and meshing has meant a move to STAR-CCM+ for the conduction/radiation problems. This integrated approach means that no FEA, FSI coupling software or radiation plug-ins are required, even with the explicit coupling approach.

The Vehicle Thermal model sizes are kept to an efficient size by a significant new STAR-CCM+ enhancement: thin solid meshing. The technology will automatically identify components that are thin-walled in shape, and make use of prism extrusions to mesh. Since many body and frame

q BELOWThe single integrated environment and new part feature of STAR-CCM+ drastically reduces model preparation time for component thermal analysis

❐ ONLINE AUTOMOTIVE CENTRE

www.cd-adapco.com/auto

AutomotiveApplication centre

For the past twenty-five years leading automotive

companies have relied on CD-adapco’s

state-of-the-art technology to improve their

designs. STAR-CCM+, STAR-CD and the STAR-CAD

Series provide engineers with an advanced and

complete CFD toolkit. This unique approach

brings unrivalled ease-of-use and automation to

CAD preparation, meshing, model set-up and

iterative design studies, enabling engineers to

deliver better results, faster.

CD-adapco’s automotive team have pioneered

many new application areas as diverse as brake

cooling and crankcase analysis. The company

has delivered CFD and FEA projects to all the top

automotive companies world wide. New product

releases, on going training and educational

programs are helping customers keep pace with

the evolving automotive industry.

Vehicle Simulation resource center

Want to know how we are impacting auto

companies world-wide?

Visit our Automotive resource center for customer

examples highlighting applications like:

• Aerodynamics

• Fuel Cells

• Powertrain

• Vehicle Thermal Management

• Passenger Comfort and Aeroacoustics

• Aftertreatment

❐ TRAINING

cd-adapco is pleased to offer a dedicated ‘Engine compartment Thermal Modeling’ course:

Your instructor will guide you through the fundamental approach and best-practices in applying

CFD for thermal simulations in engine compartment and underhood environments.

This will help increase your knowledge in the simulation approach for full 3D vehicle thermal

simulations. During this course, you should expect to learn and understand:

• How to significantly reduce simulation turn-around time using CD-adapco’s

unique “fast-track” approach for the complete thermal simulation process

from CAD to solution.

• JAVA based macro set-up for automation for DFSS and “what-if” type projects

• Best practices in generating underhood/engine compartment models including

• Critical component temperature predictions (engine mounts, rubber hosing

temperatures)

• Getting the most out of your thermal models so that final climate wind-tunnel

testing is more productive and cost effective.

For more information go to: http://www.cd-adapco.com/training/



components are sheet metal stampings, this can dramatically reduce the cell

count in the model.

Another very important enhancement introduced in STAR-CCM+ 4.02, is

the “parts” structure mirroring more closely the organization of the original

CAD data. With potentially thousands of parts to assemble, it is important to

maintain a sensible hierarchy to the model, and this is addressed by recent

developments.

Whatever method used, it is clear that vehicle thermal prediction is a

necessary component of the underhood simulation process. It can augment

the testing process, reduce the number of design iterations, and avoid costly

warranty issues.

For the Engineering Services Team as CD-adapco, using STAR-CCM+ is key

to our success in performing this type of simulation. At both the system and

component level, the advances in the software and methods have allowed us to

provide a service that can truly support the design process, while staying within

the design loop. <

i FOR MORE INFORMATION VISIT THE NEW VEHICLE SIMULATION RESOURCE CENTER http://solutions.cd-adapco.com

p ABOVE & TOPThe placement of electronic components near the exhaust system makes thermal analysis a critical consideration.

..::FEATurE ArTIcLE Electric


At Tesla Motors we run lean and go fast. This is true of our vehicles and of our engineering and analysis teams, who have developed today’s all electric Roadster, the only highway capable electric vehicle currently in production, with a 240+ mile range and a 0-60 mph time of 3.9 seconds.

It is no surprise that in 2008, when Tesla decided to bring the aerodynamics development and thermal engineering of its new Model S sedan in-house, that we chose the STAR-CCM+ Computational Fluid Dynamics software from CD-adapco to help address a broad range of

electric vehicle engineering challenges quickly and accurately. With a range up to 300 miles, the Model S Sedan (which is due to hit the

streets in 2011) can carry five adults in quiet, stylish comfort and can be charged from any electrical outlet, without ever stopping for gas. Compared to competitors whose typical range comes up to 60 miles, this represents a huge advantage. Recharging batteries on Tesla Motors’ cars is as simple as recharging a cellular phone – it takes about 3.5 hours for full recharge. Additional features like regenerative braking – which recovers and stores the energy usually lost when the car slows down – extends the charge even further, delivering higher miles-per-charge on in-town driving. All these features enabled Tesla Motors’ cars to run as inexpensive as 1 US cent per mile. All of this is delivered without compromise to performance; its peak torque starts at 0 RPM and stays powerful at 14,000 RPM. This is exactly of the

experience with gasoline engines which have very little torque at low RPM and only reaches peak torque in a narrow range of RPM. The nearly constant torque of Tesla Motors’ cars result in great acceleration with highest energy efficiency at the same time.

The floor-mounted power-train results in unparalleled cargo room and versatility by providing additional cargo volume under the hood. The packaging efficiency gives the Model S more trunk space than any other sedan on the market and more than most SUVs.

To achieve the exceptional range of the Model S, every aspect of the vehicle is analyzed to conserve energy. Range in the simplest terms is the net result of the on-board energy carrying capacity of the vehicle, and the efficiency in applying that energy to accelerate and propel the vehicle’s mass minus all the opposing forces including rolling resistance, gravity on grade, and aerodynamic drag. At highway speeds aerodynamic forces dominate the opposing forces, and it’s easy to see that to achieve increases in range two of the most effective means are reducing the aerodynamic drag of the vehicle and adding more on-board energy capacity. g

p ABOVEThe final production car ready for entry into the competition.



TESLA ModEL S - oVErVIEW

300 mile range- 45 minute QuickCharge- 0-60 mph in 5.6 seconds- Seats 7 people- More cargo space than sedans- 2X as efficient as hybrids- 17 inch infotainment touchscreen

Finally...

The World’s First Mass-Produced Electric Vehicle cFd Simulation of Lean, Green & Frighteningly Mean Tesla Model S.Vince Johnston, Engineering Manager, Tesla Motors

..::rEGuLArS Electric


Increasing battery energy capacity typically increases the cost, weight, and battery size, and is also likely to increase the amount of thermal energy required to be rejected from the vehicle. Heat transfer devices such as radiators and condensers work well in removing heat from the vehicle, but this is often at the cost of aerodynamic performance and further energy losses through the use of electric fans coupled to the heat exchangers. CD-adapco’s STAR-CCM+ software provide Tesla Motors with a tool to simulate and evaluate all of the aero-thermal components and interactions to optimize range performance and minimize vehicle energy consumption.

STAR-CCM+ is deployed among several groups at Tesla Motors including Aerodynamics, HVAC Systems and Power-train Engineering.

A key to its successful deployment is the ability to go from CAD model to CFD solution within one tool, allowing expertise in CAD correction, computational mesh generation and physics modeling to develop within a single platform across a broad range of users. Within STAR-CCM+ it’s a straight forward process to add, remove or modify geometry and physics models, allowing engineers to quickly see the results of modifications on quantities like drag, lift, pressure loss, temperature and mass flow.

Model S doesn’t compromise on performance, efficiency or utility, and with STAR-CCM+ for fluid and thermal simulation at Tesla Motors there is no comprise when it comes to finding the right solutions quickly and efficiently. <

oVErVIEW

With a range up to 300 miles and 45-minute

QuickCharge, the Model S can carry five adults

and two children in quiet comfort - and you can

charge it from any outlet, without ever stopping

for gas. World’s first mass-produced electric

vehicle offers performance, efficiency and

unrivaled utility, making it the only car you’ll ever

need.

rAnGE

Three battery pack options offer a range of

160, 230 or 300 miles per charge. With the

45 minute QuickCharge or a 5 minute battery

swap, you can drive from LA to San Francisco,

Washington to New York or take even longer road

trips in about the same time as in a conventional

car.

uTILITY

With seating for five adults and two children,

plus an additional trunk under the hood, Model

S has passenger carrying capacity and versatility

rivaling SUVs and minivans. Rear seats fold flat,

and the hatch gives way to a roomy opening, so

you can stow a mountain bike, 50-inch flat-screen

TV, full drum set or futon frame – more than

ample for the entire family and their gear.

PErForMAncE

Model S offers 100 percent torque, 100 percent

of the time without jerky shifting and a fraction of

the noise and harshness of internal combustion

engines. This smooth and constant power

delivery, combined with the sporty handling of

the chassis and suspension, leads to a superior

driving experience.

TESLA ModEL S SPEcIFIcATIonS

WhY ThE nAME TESLA?The namesake of Tesla Motors company is the genius Nikola Tesla,

an inventor, electrical engineer and scientist. Among his life’s many

inventions (and more than 700 patents) are the induction motor and

alternating-current (AC) power transmission. Without Tesla’s vision

and brilliance, the wheels of industry would cease to turn and the

Tesla Motors’ cars wouldn’t be possible. His name marks an epoch

in the advance of electrical science.

i FOR MORE INFORMATION ON TESLA MOTORS PLEASE VISIT: http://www.teslamotors.com



TEchnoLoGY

The Model S powertrain features a liquid-cooled, floor-

mounted battery pack and a single-speed gearbox, delivering

effortless acceleration, responsive handling and quiet

simplicity -- no fancy clutchwork or gear-shifting required.

Model S costs about $4 to fully charge – a bargain even

when gasoline is $1 per gallon. You can listen to Pandora

Radio or consult Google Maps on the 17 inch touchscreen

with in-car 3G connectivity.

❐ FACTS

TESLA MoTorSAt the core of Tesla Motors is the belief that an electric car need not be a driving sacrifice. We have

brought the best of the automotive and technology worlds together to permanently bury the image

of an electric car as a step backwards in performance, efficiency, or design. Our key technology is

the 100% electric powertrain, which propels us in the present and simultaneously establishes a

foundation for our future models. We set out to forever alter perceptions of electric vehicles and to

make electric cars a viable alternative. We have produced a car that is at once beautiful and exciting

to drive, along with being the most efficient production automobile on the planet.

Keeping an Eye on Tomorrow, TodayIt probably comes as no surprise that a forward thinking company like Tesla Motors thinks a lot about

the future. That is why the tires and the battery of every Tesla Motors vehicle are recyclable. Reuse is

such a key part of Tesla Motors’ philosophy that they’ve already arranged to have car batteries safely recycled - even before the first Tesla car was sold. The cost of recycling is built into the purchase price

of the car, so there is never a reason why not to recycle.

Modeling of Battery Systems & Installations for Automotive ApplicationsEven a casual automotive industry observer would not have failed to miss the huge efforts

being devoted to electric vehicles in recent years. None of the competing new technologies,

such as alternative fuels and fuel cells, has gained the momentum of battery-powered vehicles,

from mild hybrids and PHEV’s to full EVs in such a short space of time.

u Lithium ion battery 3D.

Indeed, it is difficult to find any auto OEM that does not have either EV

vehicles in production or in advanced development. Batteries have emerged

as a key technology to the success of EVs and this has resulted in a

business environment with OEMs, tier 1 suppliers and cell manufacturers

forming JVs and alliances to deliver complete battery pack solutions.

However, as with any new technology, there are both opportunities and

challenges. The opportunities are clear: “Green” technology with potential

image and taxation benefits, premium pricing, rapidly growing EV market

etc. Although not so obvious, there are a number of challenges that OEMs

and suppliers must address. Battery technology is a fast-moving field (or

minefield for the unwary) - weekly announcements from all corners of the

globe on improved lifetime, capacity, cost and safety from both major cell

suppliers and start-ups promise technology leapfrogs. Should the OEM go

with one cell manufacturer or have a flexible sourcing policy to be able to

move quickly as improved technology emerges?

One aspect of battery systems that has rapidly gained increased

engineering importance is that of thermal management; temperature affects

lifetime, durability, performance and safety, all of which are critical to the

success of the vehicle. It has also become apparent that the CAE tools,

upon which the auto industry relies heavily for product development, have

not been available to address thermal management of large-scale battery

installations. The problem is technically challenging - cell performance

depends on temperature, yet temperature depends upon the cell, pack,

cooling system and installation design and operating conditions. Although

analysis tools are available to address vehicle thermal management issues,

these have not until now been able to solve large-scale problems whilst

coupled to cell models.

To deliver an optimum solution, CD-adapco and Battery Design LLC

formed a partnership in early 2009 to deliver a fully coupled flow-thermal-cell

solution for solving large scale battery problems. CD-adapco has been

developing and using analysis software for fluid flow, heat transfer and

stress analysis for nearly 30 years and is heavily ensconced in the

automotive industry worldwide; one particular area of strength is total vehicle

thermal management. Battery Design LLC is a company specializing in the

design and modeling of Li-ion batteries for more than a decade and consults

widely to the battery and cell industry.

p Mercedes S400 thermal analysis showing installed lithium ion battery pack.

Courtesy Daimler



richard Johns - Automotive director, cd-adapco & robert Spotnitz - President, Battery design LLc

p Lithium ion battery - Courtesy BEHR.



i FOR MORE INFORMATION ON OUR AUTOMOTIVE APPLICATIONS: www.cd-adapco.com/applications/automotive

Specifically, all of the fluid flow and heat-transfer capabilities, including

multiple fluid-solid domains, conjugate heat transfer, multi-phase flow,

radiation etc available in STAR-CCM+ are coupled to the full range of cell

models developed by Battery Design. These include fast simple-circuit

models for routine thermal analysis to enhanced electro-chemistry models

where non-linear behaviour is critical, such as short circuits and thermal

runaway. Additionally, all of the powerful pre and post processing tools

required for CAD import, surface preparation, automatic meshing, model

setup and visualization are available in the STAR-CCM+ environment.

Simulating battery systems is intrinsically a transient problem - the

State-of-Charge (SOC), and hence the battery characteristics, are changing

continuously. Additionally, thermal transients are of fundamental interest,

typically for a drive cycle of around 20 to 30 minutes. The software has

therefore been designed to be able to undertake such unsteady calculations

in which the flow, thermal and electrical time-scales are accounted for

properly.

One of the challenges to solving such problems is not just the

possession of an appropriate analysis tool but also a clear engineering

process - the ability to go from a battery design and experimental cell data to

a viable result. Much effort has been devoted to developing this process so

that, with the new STAR-CCM+ solution, users will be able to deliver realistic

results as fast as possible. <

..::FEATurE ArTIcLE Fuel Cell


clean, Green & Frighteningly Fast: cd-adapco helps Ford break the land-speed record for fuel-cell powered cars Tim o’Brien, Ford Motor company. dejan Matic, cd-adapco.

Traveling at 207mph, without consuming an ounce of gasoline and leaving nothing but a trail of water-vapor, Ford’s record breaking Fusion Hydrogen 999 recently demonstrated that “Clean and Green” doesn’t have to come at the expense of drivability.



Ford is becoming smaller, leaner, more globally integrated

and more focused on meeting

customers' needs and wants.

It is also a company with

sustainability at the heart of its

business. Our vision for the 21st

century is to provide sustainable

transportation that is affordable

in every sense of the word:

socially, environmentally and

economically.Alan r. Mulally

President and Chief Executive Officer

named after an early 1900’s vehicle that reached speeds near 100mph, the Ford Fusion Hydrogen 999 is powered by the latest fuel-cell technology and designed using cutting-edge Computa-tional Fluid Dynamic simulation. It has replicated the success of its famous namesake, by becoming the first production based fuel cell powered car to travel at over 200mph.This record breaking vehicle has a serious message: to demonstrate that sustainability can be achieved without compromising drivability. In practical terms, sustainability means companies taking into account not just financial outcomes, but also environmental and social performance. Ford Motor Company takes a no-compromise approach towards integrating sustain-ability into all aspects of its business strategy: “Sustainability is about making people’s lives better,” said Tim O’Brien, Ford’s deputy chief of staff, executive operations and sustainability. “That’s the essence of any successful product, whether you are talking about an iPod, an automobile or a taco.”

Ford’s strategy for alternative fuels is built around multiple technologies, including hydrogen fuel cells. This flexible approach allows the company to meet goals for customer needs, environ-mental impact and shareholder interests. The strategy does not focus on a one catch-all solution, but includes a flexible array of options, including hybrids, E85 ethanol, clean diesels, bio-diesels, advanced engine and transmission technologies as well as hydrogen fuel cells. While developing sustainable vehicles, maintaining drivability key:

“The point is, people often drive the vehicle they think they have to drive even though they’d really like to drive something else. But we are working on designing vehicles that not only support the sustainability agenda, but are exciting vehicles that people want to drive,” says O’Brien.

The Ford Fusion 999 also reflects the company’s proud heritage of involvement in motorsports: “Racing is part of Ford Motor Company’s DNA so it seemed only natural for us to build a fuel cell race car that runs on hydrogen, a fuel that could some day play a key role in meeting the energy needs of the transpor-tation sector,” said Gerhard Schmidt, Vice President, Research & Advanced Engineering for Ford Motor Company. “Our goal in attempting this record is to further expand our technological horizons with fuel cell powered vehicles. The collaboration with Ohio State University also affords us an opportunity to work closely with a prestigious university, which provides out-of-the-box thinking from student engineers and helps us recruit talented young people to work at Ford Motor Company.”The Ford Fusion Hydrogen 999 is a collaborative effort among Ford, Roush, Ballard Power Systems and Ohio State University. The car was designed by Ford engineers while Roush provided motorsport expertise and a workshop in which the car was constructed. The team of Ohio State’s University students provided the design of a 770 hp electric motor, giving the opportunity to Ford to recruit talented young people from a prestigious university.

p Fig:03a-cThe Ford Fusion Hydrogen 999 car's number is rooted in Ford's land speed history. The triple-nine was used on several of Henry Ford's early racers, most notably one that set a record in 1903 with an average speed of 91.32 mph over frozen Lake St. Clair.



Given that aerodynamic drag increases with velocity squared, it takes an enormous amount of power to run any vehicle at over 200 mph, especially for what is essentially a modified production vehicle. Roush engineers therefore dedicated special attention to drag reduction, since for a given engine output the drag of the vehicle essentially determines its maximum speed.

The drag optimization was performed numerically using CD-adapco’s STAR-CCM+ Computational Fluid Dynamics software, which allowed Roush engineers to rapidly examine the impact of multiple design configurations from the comfort of their desktop computers, including the analyses of different underbody and rear-wing configurations, all of which were benchmarked against the original car. As well as reducing drag, STAR-CCM+ also helped increase the high-speed stability of the vehicle, by demonstrating that the addition of a rear spoiler significantly reduced the body generated lift.

“Drag reduction of the Ford Fusion 999 was a key element of the successful world record attempt. By taking advantage of CFD analysis, physical test times could be reduced and multiple configurations of the vehicle studied. Other benefits included insights such as adding a rear spoiler for stability,”

John W. Zaleski, Program Manager, Roush Industries. “Through several design iteration we managed to reduce the drag coefficient of the vehicle from 0.34 to 0.21, helping the Fusion to become the first fuel cell powered car to pass the 200 mph barrier. Our partnership with CD-adapco in our use of STAR-CCM+, allowed us to draw from a great pool of expertise spanning both CFD and vehicle aerodynamics.”

The engineering effort expended designing, testing and manufacturing the Ford Fusion Hydrogen 999 is nothing short of exceptional. The fuel and power plant system consist of two Heliox tanks, one Hydrogen tank, the fuel cell system, a DC/AC inverter and an induction motor. The fuel cell system developed by Ballard chemically changes hydrogen atoms into electrical current with heat and water as by-products. It delivers DC current to an inverter, which

converts current to AC and drives a 3 phase 770 hp induction motor. In order to maximize fuel cell power delivery, it was decided not to use ambient air for the catalytic process, but to carry all oxygen required for the speed record attempt. The oxygen is stored in tanks as a Heliox mix which contains 60% Helium and 40% Oxygen. For the purpose of reducing aerodynamic drag, the front of the car is closed to airflow so the only cooling provided for the fuel cells is ice cold water stored in a 400-litre tank.

The culmination of the project occurred on August 15, 2007 at the Bonneville Salt Flats in Utah, a location synonymous with speed having seen the world land speed record broken no fewer than 18 times. It was here that the Ford Motor Company became the first automaker to set a land speed record for a production-based fuel cell car when Ford Fusion Hydrogen 999 raced to 207.297 mph. With this latest environmental innovation and a historic run at Bonneville, Ford is looking to further expand the company’s technological horizons with fuel cell powered vehicles. They are hoping that lessons learned from this project will feed future fuel cell vehicle development with a goal of reducing vehicle complexity and cost, while making the designs more efficient, and by joint venturing the production of the fastest and cleanest speed record vehicle ever designed, CD-adapco continues to actively participate in providing ecologically viable industrial development. <

❐ FACTS

The Ford Fusion Hydrogen 999 car’s number is rooted in Ford’s land speed

history. The triple-nine was used on several of Henry Ford’s early racers, most

notably one that set a record in 1903 with an average speed of 91.32 mph over

frozen Lake St. Clair. That vehicle has since been restored and is on display at

the Henry Ford Museum.

p Fig:03a-cThe Ford Fusion Hydrogen 999 car's number is rooted in Ford's land speed history. The triple-nine was used on several of Henry Ford's early racers, most notably one that set a record in 1903 with an average speed of 91.32 mph over frozen Lake St. Clair.

i MORE INFORMATION ON FORD MOTORS www.ford.com



Ford’s History of Alternative Fuel Innovations

Ford’s involvement in the development of alternative fuel vehicles has a long history, beginning with its founder,

Henry Ford. Besides being an industrialist, Ford was a conservationist who preferred harnessing nature as an energy

source and using zero-emission hydroelectric energy. Today, Ford Motor Company is deeply involved in research and

development of alternative fuels for the future, including plug-in hybrids, hydrogen and hydrogen fuel cells.

The company devotes a significant percentage of its scientific research budget to environmental efforts toward a world

where motorized transportation is cleaner, more fuel efficient and generally less harmful to the natural environment.

http://www.ford.com/our-values/environment

❐THE FORD ARCHIVES

Ford ThrouGh ThE YEArS

..::FEATurE ArTIcLE Racing


Marco Giachi, Eng., centro Studi Storici di Assomotoracing.dr. Anthony Massobrio, cd-adapco.

One of the most interesting aspects of competition motor racing is watching the gradual development of the vehicles’ technical features over the years, the most impor tant of which provide a snapshot view of leading aerodynamic design thinking of that time. It is impor tant to know the histor y of motor racing technology not only for purely cultural reasons, but for educational reasons too, in order to train young engineers and future aerodynamics designers.

Numerical simulation provides an extremely useful tool for reviewing the decisions made; not for criticizing or judging, but for interpreting and understanding the problems encountered and the inspiration, of the designers of the past. With this in mind Assomotoracing and CD-adapco set about studying the 1973 Ferrari Spazzaneve.

cFd helps to understand the history and evolution of racing techniques: the 1973 Ferrari “Spazzaneve” [Snowplough]

Simulate To understand

ASSoMoTorAcInG is a non-profit democratic association, providing educational services to anyone interested

in studying the history and technological developments of the motor racing industry. The organisation provides

lectures to universities, technical high schools, museums, and trade shows both in Italy and abroad.

Members of ASSOMOTORACING are not only individuals and companies with specific technical knowledge but

anyone with an interest and passion for motor racing.



Founded in 2006 with the aim of promoting the technical aspects of competition motor racing, Assomotoracing is a non-profit-making cultural association that operates nationally but has contacts abroad, mainly with the English speaking world. In the first two years

of its life, it took part in a large number of trade shows and conferences, including the coordination of Technical Sessions at Motorsport Expotech event in Modena (the first exhibition for car and motorcycle operators “in the racing industry”), as well as publishing its own journal (R&T – Racing & Technologies).

Assomotoracing’s Historical Studies Centre deals with the historical aspects of technological development with the association’s activities carried out mainly in collaboration with external bodies, companies and universities. Recently, however, the Historical Studies Centre has been equipped with a computer centre in order to independently carry out less computationally demanding research, while external contributions (especially from CD-adapco) will be used for the more demanding and complex simulations.

Numerical simulation - CFD for the aspects linked to aerodynamics - can be extremely helpful in studying the history of motor racing technology in order to review the choices made by designers over the years, understand them, interpret them and calculate their effectiveness, all aspects of primary importance when training young engineers. The work started with a careful study of structures through a review of original drawings, notes taken from the existing models and research into historical documents (giving preference to those from the same period as the vehicle being studied) and concluding (where possible) with meeting the designer, in order to exchange comments on and discuss the work carried out. These same designers were also often involved before the final discussion, so that they could be consulted at all stages of the research.

At the end of 1972, Ferrari was not performing very well, their last drivers’ world title had been won eight years earlier by John Surtees and in the second half of the nineteen-sixties, the British teams (the “garagists” as Enzo Ferrari used to call them, meaning small stables of assemblers which, in his opinion, were not true builders of racing cars) had driven the Maranello House into a tight corner. Ferrari’s Formula One progamee was not without its technological

successes. At the 1968 Grand Prix in Belgium, Ferrari introduced wings with “gently” lifting spoilers at the barycentric point, however during this time aerody-namics research was principaaly conentrated on sports vehicles with covered wheels.

The Engineer Mauro Forghieri, Technical Director of Ferrari’s Sports Management for nearly thirty years, explained that “…at that time, numerical simulation was still a long way off and we often went to the Wind Tunnel at Stuttgart University. We were all really surprised at the effect of aerodynamics on performance for F1, but it was thought that the sports car’s greatest potential was in the larger surface area on the base of the bodywork. It was not exactly the ground effect, because it was still considered better to work on the upper part of the bodywork and less on the lower, but the idea of exploiting the whole body of the vehicle and not just the wings in order to produce a vertical load was already taking shape…”.

The “Snowplough” was created with this in mind and marked the shift from the “torpedo” single-seater shape to a “wide body”, which would lead six years later to the ground effect of the Lotus 79. Its aim was not only to verify aerodynamic theories, but also the dynamics of the vehicle with its extremely short wheelbase, which simulated the polar inertia of a transverse gear as would appear two years later on the T type Ferrari series, winning three drivers’ titles with Niki Lauda (1975, 1977) and Jody Scheckter (1979) and 4 construction titles (1975, 1976, 1977, 1979).

Numerical simulation started from the generation of the 3D vehicle geometry thanks also to the support of the vehicle’s current owner who very kindly provided his collection of original engineering drawings as well as the vehicle itself enabling the study of structural components not visible on the drawings. To create a CAD reconstruction, we benefited from the designers’ contribution of the MG Model, a company that created special collectors models and had considerable experience as well as an archive of special CAD of the vehicles from the nineteen-sixties and seventies. For CFD simulation we were assisted by the computer workstation at the Assomotoracing Historical Studies Centre supported by the “strategic” consultations of the Engineer Lucia Sclafani of CD-adapco. g

❐ FACTS

cuLTurAL ASSocIATIon oF ThE hISTorY And TEchnIQuES oF coMPETITIon MoTor rAcInG

1973 conSTrucTorS chAMPIonShIP FInAL STAndInGS CONSTRUCTOR CHASSIS ENGINE POINTS WINS PODIUMS POLES

1. Lotus-Ford 72D 72E Ford Cosworth DFV 92 (96) 7 15 10

2. Tyrrell-Ford 005 006 Ford Cosworth DFV 82 (86) 5 15 3

3. McLaren-Ford M18C, M19C, M23. Ford Cosworth DFV 58 3 8 1

4. Brabham-Ford BT37, BT42 Ford Cosworth DFV 22 2

5. March-Ford 721G, 731 Ford Cosworth DFV 14 2

6. Ferrari 12B2, 312B3 Ferrari 001/1 & 001/11 12 7. BRM P160C, P160D, P160E BRM P142 12 18. Shadow-Ford DN1 Ford Cosworth DFV 9 2 9. Surtees-Ford TS9A, TS14A Ford Cosworth DFV 7 1 10. Iso Marlboro-Ford FX3B, IR Ford Cosworth DFV 2

The “Snowplough” - 1973

The CFD model was prepared using the surface wrapper to remove the imperfections on the CAD surface. A volume mesh was then created consisting of 1 million trimmed cells (Fig. 2) and two prismatic layers limited by an average value of y+ of approximately 40. The validity of this modeling was verified in advance, also in the educational spirit of Assomotoracing activities, by simulating the “Ahmed body” in order to check the CFD model’s ability to correctly evaluate the pressure distribution (the primary focus of the research). The car’s trim was of a sufficient distance from the ground (during static conditions, it measured 100 mm) and for this reason the simulation was carried out on solid ground.

The results of the calculations on the “Snowplough” confirm engineer Forghieri’s theories. The upper surface of the bodywork (Fig. 1) has a higher pressure than the bottom which is perfectly flat. The rear of the car decreases in width to increase flow between the gearbox and the rear wheels, a practice which became established in the design of formula one cars in the 1980s, the so called “Coca-Cola” shape (Fig. 3).

The “Snowplough” was retired at the end of 1973 after providing its designer with the information for which it had been designed and created, not only in terms of aerodynamic performance, but also details of more general dynamic behaviour relating to its extremely low moment of polar inertia. <

i MORE INFORMATION ON ASSOMOTORACING http://www.assomotoracing.it/



q Fig 01Pressure distribution across the car.

t Fig 02Detail of the trimmed cell mesh.

t Fig 03Streamlines demonstrating the effect of the “Coca Cola” shape of car.

..::FEATurE ArTIcLE Benefits


Featuring!Volume RenderingBetter PolyhedralsSession FilesDirect STAR-CD ReaderClick-n-go Interactivity

Free update for current customersFree test drives for prospectsFree EnSight CFD for small modelsFree 3D viewers to share modelsFree, Open, Public File Format



Jean-Philippe Pélaprat - orEcA, France

Le Mans Prototype: Increasing Front downforce





oreca and cFd Oreca started to work with CFD software at the beginning of 2009 and, after evaluating different packages, in Star-CCM+ we found the best compromise in terms of ease of use and accuracy. Our first aim was to have a better compre-hension of Le Mans Prototype (LMP) aerodynamics and a good support for wind tunnel testing. Moreover, CFD permits the development of the aero-package throughout the season so reducing reliance on wind tunnel testing. Aero-configurations LMP cars are designed to compete in LMS (Le Mans Series), ALMS (American Le Mans Series), Asian Le Mans Series and, of course, the 24hrs of Le Mans. The tracks used for these Championships have different characteristics. On the fastest track the top speed is over 320kph, the average speed is around 230kph and the straights represent 80% of the

track. On the slowest track, the top speed is only 290kph, the average speed is around 175kph and the straights represent 60% of the track. The aerodynamic requirements of these track types are obviously quite different so requiring the ability to analyze different configurations rapidly. The fast tracks require reduction of drag and improvement of aerodynamic efficiency, while on slow tracks the focus is on increasing the overall level of downforce. Apart from optimizing the levels of aerodynamic drag and downforce, some other aspects of race car aerodynamics such as aerodynamic balance or ride height sensitivity are studied.

Simulation Properties At Oreca, only “full-vehicle” simulations are carried out, as the addition of flaps at the front of the car can significantly alter the air flow under the car and into the rear diffuser. The k-Omega SST turbulence model was g

Depending on the configuration of the track where we race, a Le Mans Prototype can have many dif ferent aerodynamics configurations. Additionally, some pre installed par ts may be adjusted, for example the rear wing main plane and flap angle of attack. Regulations permit homologation of various versions of the aerodynamic package but place restrictions on how many changes are made. For instance, allowed is the addition of up to two “flaps” on front fenders to increase the front downforce and those are the subject of aero analysis and optimization described in the ar ticle.

Le Mans Prototype: Increasing Front downforce

ThE orEcA GrouP has been a leading contender in motor

racing for 35 years. Oreca competes in Le Mans Series and

24 hrs of Le Mans with his own prototype, and also in World

Touring Car Championship for Seat Motorsport. Two depart-

ments are concentrated on business/marketing operations:

the sale of equipment and accessories, and the Special Event

Department for marketing and incentive operations.

http://www.oreca.fr/uK

p ABOVEStreamlines over the Propulsive Wing AAUV at a high angle of attack.



used in conjunction with a trimmed hexahedral mesh, with the addition of prismatic layers on the car’s surface to increase accuracy by helping resolve flow inside the boundary layer. The floor is set up as a “moving wall”, with the tangential velocity the same as inlet velocity, while boundary conditions at the wheels and brake discs are set to have rotational velocity. Geometry tested On the front of the car, the rules and regulations allow the possibility to add two “flaps”. The “flaps” can be considered as a dive-plane or splitter endplate. The Baseline, Figure 1, was a standard HDF (High Down-Force) configuration chosen after the wind-tunnel tests: double small dive-planes, which is a good configuration in terms of efficiency. The target is to design new parts which increase the total level of downforce, switch the aero-balance to the front and keep the same level of aerodynamic efficiency.

We tested another double dive-planes configuration with bigger parts, Figure 2, and another with splitter endplates combined with dive-plane, Figure 3.

results Different configurations of the dive-planes were studied with parameters such as their height and angle of attack modified to find an optimal design. In order to evaluate the difference between the various new components, pressure coefficient (CP), wall-shear stress or Q-criterion visualizations were made and compared.

With a force report, we can check the impact of dive-plane or splitter side panel part by part. It’s easy to see, for example, if the effect of a side-panel modifies the underbody air flow or acts only under the splitter.

As a final result of this aerodynamic analysis, we found that the splitter endplate in conjunction with dive-plane is the best compromise in terms of downforce, balance and aerodynamic efficiency.

With new aerodynamic package developed using STAR-CCM+ Team ORECA Matmut AIM competed at the prestigious 2009 24 Hours of Le Mans race. The aerodynamic advances achieved during this optimization process made possible strong running during the one of the most famous races in the world. <



i MORE INFORMATION ON ORECA http://www.oreca.fr

BaseDive-Plane + Endplate

Dble

cAr

SCX - 3,48% 6,55%

SCZ - 1,80% 2,21%

FRONT BALANCE - 0,32% 1,00%

p ABOVE Closeup of the polyhedral mesh around the cross flow fan

p ABOVE Configuration 1



p ABOVE Closeup of the polyhedral mesh around the cross flow fan

For more information: [email protected]/consulting

CD-adapco...Your CAE Partner for Success

Working in a very lean manpower environment can create extra challenges in maintaining vitally important product development plans. As your ‘partner for success’, we want you to know that CD-adapco is available to help you meet that challenge.

If you have a short term need for an expert CAE engineer, we can very quickly put one of our highly experienced engineers in your offices to help.

We will match one of our own CAE engineers, already on staff, to the assignment you have and try to make it as affordable as possible. This service is creating a very easy and low risk way for customers to satisfy both their short term and longer term CAE staffing needs.

CD-adapco understands that the current state of the World Economy has forced many of our customers to make some hard choices to remain financially healthy and industrially competitive. These choices have included force reductions and hiring freezes in your engineering staffs.



❐ FACTS

Weighing just 605 kilograms in race trim, propelled by an engine that delivers in excess of 800 horsepower, a Formula 1 car is regularly subjected to braking and cornering forces in excess of 5g. The maximum speed depends on aerodynamic setup, which changes

from circuit to circuit, but is usually around 340 kph. At that speed, the geometry of the car produces downforce of around two tons. This invisible force pushes the car into the ground, increasing traction and allowing the car to maintain higher cornering speeds and generate greater braking force. Since both lift (in this case negative lift) and drag are functions of velocity squared, the ability to deliver an efficient aerodynamic package on raceday is a critical ingredient in reducing individual lap times by the fractions of a second that combined are

the difference between winning and losing the race. With engine development now frozen and only one tyre manufacturer supplying the whole grid, the aerodynamic package has become a single most important component of race car performance.

The development of a car’s aerodynamic package typically relies on an extensive wind tunnel programme, conducted in parallel with, and to some extent driven by, an even more extensive Computational Fluid Dynamics (CFD) programme. In this mode CFD is largely used as a coarse filter, examining many possible design variants, from which only the best will be tested in the wind-tunnel, CFD also plays a valuable role in simulating physics that can not be adequately handled by the wind-tunnel, for example where thermal effects

chassis

Moulded carbon fibre and aluminium honeycomb

composite monocoque, manufactured by the

Renault F1 Team and designed for maximum

strength with minimum weight. RS27 V8 engine

installed as a fully-stressed member.

Front suspension

Carbon fibre top and bottom wishbones operate

an inboard rocker via a pushrod system. This

is connected to a torsion bar and damper

units which are mounted inside the front of

the monocoque. MMC aluminium uprights and

machined magnesium wheels.

rear suspension

Carbon fibre top and bottom wishbones operat-

ing angled torsion bars and transverse-mounted

damper units mounted on the top of the gearbox

casing. MMC aluminium uprights and machined

magnesium wheels.

Transmission

Seven-speed semi-automatic carbontitanium

gearbox with reverse gear. “Quickshift” system in

operation to maximise speed of gearshifts.

Fuel system

Kevlar-reinforced rubber fuel cell by ATL.

Formula 1 is the world largest annual spor ting event with over one billion cumulative viewers in 184 countries watching races across four continents. In the world of speed where fractions of second determine the dif ference between the first and last, the competition takes place not only at the race track but in the factor y as well. Branded with the name that por trays the vision of racing excellence, Formula 1 became the leading arena for development and testing of advanced automotive technologies.

rEnAuLT F1 r29 SPEcIFIcATIonS

The first thing that separates them from the competition is STAR-CCM+, its a state of the art CFD code and since we introduced it about a year ago we have managed to double our throughput in terms of simulations, so it was a massive step forward.



InG renault F1 Team takes the lead with STAr-ccM+

are important, or where multiple cars interact with one and other (such as the simulation of a passing manaouver). It is also used to explain, and visualize flow mechanisms observed during physical testing, helping optimize any new design modifications so that any potential benefit is maximized. The FIA’s (Federation Internationale de l’Automobile) current focus on reduction of the costs of race car development by limiting time in wind tunnels will certainly increase the importance of, and reliance on, CFD technology.

After several months of in-depth reflection by ING Renault F1’s aerody-namics group, a decision was made to invest in a virtual wind tunnel instead of a physical one:

“The decision to head towards a wind tunnel in a computer rather than constructing expensive second wind tunnel is down to the teams strategic approach”, says Bob Bell, ING Renault F1 team Technical Director. “It was a fairly clear cut decision for us based on first, and foremost, technical belief that was the way of the future and it was also based on some pragmatic commercial judgment. This facility has cost us less than an equivalent wind tunnel capacity would be and it’s also a facility that is of interest to potential partners and sponsors.”

The new supercomputer, which was set to work in November 2008, provides the ING Renault F1 team with a five-fold increase in computing capacity, allowing the team to push the limits of CFD technology by simulating real track

conditions with increased accuracy. Based in a newly constructed sub-terrain facility at the Team’s Enstone headquarters, the new supercomputer will be used, almost entirely, to run simulations using STAR-CCM+:

“In 2008 we signed a three year partnership with CD-adapco. An important part of this is the increased access that we gained to CD-adapco’s expertise”, says Jarrod Murphy, Head of CFD Department at ING Renault F1 team. “STAR-CCM+ is a state of the art CFD code that’s relatively new and is fast, robust and extremely easy to use”.

The design of a race car is a continuous iterative process that starts with review of both CFD and wind tunnel test data together with telemetry data gathered from the car. Based on those observations the new geometry is then either generated or re-designed using CAD (computer aided design), the team of aerodynamicists then develops a collection of possible configurations which are analyzed using CFD. This iterative process of surface optimization includes surface clean up, mesh generation and numerical calculation yielding the final aerodynamic loads. In the intensely competitive environment of Formula 1, in which new modifications are often unveiled on a race by race basis, it is important to make this iterative process as automated as possible so that engineers can focus on analysis and innovation rather than manually preparing CFD calculations. A significant advantage of STAR CCM+, over any other CFD tool, is that the whole process is completely automated from the point of g

KErS

Motor generator unit driving into front of engine

with batteries as an energy store.

cooling system

Separate oil and water radiators located in the

car’s sidepods and cooled using airflow from the

car’s forward motion

Electrical

MES-Microsoft Standard Electronic Control Unit.

Magnetti-Marelli KERS control unit.

Braking system

Carbon discs and pads (Hitco); calipers and

mastercylinders by AP Racing.

cockpit

Removable driver’s seat made of anatomically

formed carbon composite, with six-point harness

seat belt. Steering wheel integrates gear change

and clutch paddles, front flap adjuster and KERS

energy release controls.

car dimensions and weight

Front track 1450 mm

Rear track 1400 mm

Overall length 4800 mm

Overall height 950 mm

Overall width 1800 mm

Overall weight 605 kg (driver, cameras & ballast)

dejan Matic, cd-adapco.Images: courtesy InG renault F1 Team

i MORE INFORMATION ON ING RENAULT F1 TEAM http://www.ing-renaultf1.com

CAD geometry import through to report generation once the solution is complete, a feature of STAR CCM+ that Jarrod Murphy outlines as a key attribute:

“Model update time is significantly reduced due to the automated mesh pipeline functionality of STAR CCM+. It is very robust and always produces a high quality volume mesh with no user input. These features make STAR CCM+ ideal for design optimization”.

Repeatability of computational model creation is also critical as the front and rear wing, brake ducting or wing endplates are liable to change on a race by race basis. When it comes to the constantly evolving design of these components, turnaround time is critical, the associative nature of settings inside STAR CCM+ means that modified components are easily replaced and the volume mesh regenerated automatically with exactly the same settings, dramatically reducing run-times and significantly improving engineering output.

In the case of deflection sensitive component, such as the front wing, where proximity to the ground is a critical parameter, the results the aerodynamics loads are automatically passed to ING Renault F1’s structural analysis group to determine stress levels on the new components, as well as structural integrity and deflections. The deflected shape is then passed back to the CFD department so new aerodynamic loads and balance may be assessed. Finally, the components are evaluated at race track testing days which is usually final step before they end up on the race car (although from the beginning of the 2009 season, testing restrictions will seriously limit this capability).

Although the primary use of CFD technology is aerodynamic analysis, it also has many other uses within the car’s design cycle. The study of thermal

management is another example where CFD is very useful, the full car thermal analysis includes radiator heat rejection, exhaust gas blowing and front and rear brake disc heat rejection. Proper investigation into location and magnitude of these hot air flows is critical as the structural integrity of components may be compromised if over-heated. The most obvious location where this can become a serious problem is on the rear wing whose temperature may be increased significantly due to the proximity of exhaust plumes. These thermal analyses are almost exclusively carried out using CFD, as wind tunnel testing of such flows and the reproduction of temperatures experienced during racing is extremely complex.

With recent restrictions in wind-tunnel and track testing, CFD is playing an even more critical role in the development of Formula 1 cars, last year at the ING Renault F1 team, CFD was responsible for 10-20 percent of the increased aerodynamic efficiency of the car as the season progressed. This year, with a new supercomputer available to the team and the advanced features of STAR-CCM+ software, they expect much more than that.

“A key factor”, says Jarrod Murphy, “in the strength of CFD at ING Renault F1 team is the close partnership we have developed over the years with CD-adapco. I am continually impressed with CD-adapco in terms of support and their willingness to take on board development requests. STAR-CCM+ is being developed at a very fast rate and very often it is only a few months before a particular request from ING Renault f1 has been incorporated into the production code.” <





InG renault F1 Team unveils the r29 in PortugalThe ING Renault F1 Team officially launched its 2009 season on the 19th January as the new

Renault F1 R29 was unveiled to the world’s media at the Algarve Motor Park near Portimao in the

south of Portugal.

With radical revisions to the sport’s technical regulations introduced this year, the R29 incorporates

a new design philosophy and looks very different from its predecessor. Great attention has been

paid to maximizing the new rules and the team is optimistic about its chances for the year ahead,

as Flavio Briatore explained: “We began our preparations for the R29 project early and I am proud

of what the team has achieved. There are lots of new things to deal with this year, which could

shake things up, but we intend to continue fighting at the front. We will now concentrate on our

final preparations for the start of the season so that we can arrive in Australia hopefully fighting

for the podium.”



Every year in May during the first week of summer school break, students from 120 Universities descend on Detroit Michigan for a unique competition. For one week only, the Michigan International Speedway becomes the international centre of young engineering

talent as hundreds of hours of work (and occasional sleepless weekend spent in the school machine shop) come to fruition. The outcome of this dedication is a formula style race car designed and manufactured entirely by students. With strictly defined rules and regulations, students produce a completely new race car every year.

The competition bears name of the Society of Automotive Engineers (SAE), which organizes and governs the event, and provides leading specialists from the automotive industry as judges. Established in 1981 by the University of Texas, the first Formula SAE competition attracted just a handful of Univer-sities from the United States. Since then it has become a widely recognized international University program that inspires students from all around the world to excel in theengineering challenge of race car manufacturing. It is an international competition with venues in Australia, Japan, USA and Europe. Some of the most successful challengers outside of the United States come from Germany, Australia and the UK.

Soon after inception of Formula SAE, the automotive giant General Motors began to take notice of the competition followed by Ford and then Chrysler. Realizing the potential behind this program, the competition became jointly staged by a consortium with representatives from these three car manufac-turers. Besides the challenging competition, it is also a place for the profes-sional recruitment of entry level engineers, many of the recent graduates find a job with one of the team sponsors immediately after the completion of their

course. For any student with aspirations for further involvement in the car racing industry, Formula SAE represents an important first step.

The answers to the usual three questions that casual spectator asks about Formula SAE are “130mph”, “$200,000” and “No” where the last question is “Can I drive it?”. The price of the race car is calculated taking into consideration material, tools and the number of man-hours team members put into the project. The top speed of 130mph greatly depends on aerodynamic properties of the car, more precisely if the car has wings or not. Many schools decide not to develop aerodynamic devices and benefit from the reduced car weight.

Even though the car performance compares well with its more famous relatives from the world of professional racing, the Formula SAE competition is more of an engineering challenge than traditional track race. The competition includes a combination of dynamic and static events such as autocross, drag racing and a design event, during which every car is scrutinized by the judges and marked against a range of criteria. During the design event students are tested on their knowledge of physics, vehicle dynamics, aerodynamics or material science and asked to defend their design ideas.

The race car is powered by a production motorcycle engine, the power of which is limited by an air intake restrictor for safety reasons. This usually requires some adaptations since the computer program that governs the amount of fuel injected into the engine cannot compensate for the reduced aspiration. In order to maintain maximum power throughout the whole range of engine speeds, students have to build a new fuel injection map. This is where the CFD simulation of engine intake comes into its own, with the engine dynamometer available, MSU Formula SAE students can easily validate the CFD results and then expand on them introducing variations into intake design. g

Attracted by its versatility and accuracy, The Michigan State University (MSU) Formula SAE team is using STAR-CCM+ to design a 2009 Formula SAE race car.

James Guitar - Michigan State university dejan Matic & Lauren Wright, cd-adapco

Formula for Success

PoInTS SchEduLE For MoST ForMuLA SAE EVEnTS

Design Event 150

Cost & Manufacturing Analysis Event 100

Presentation Event 75

Acceleration Event 75

Skidpad Event 50

Autocross Event 150

Fuel Economy Event 100

Endurance Event 300

Total Points Possible 1,000

❐ FACTS



p ABOVEThe final production car ready for entry into the competition.

Instead of taking time and money consuming efforts of building physical prototypes, they can optimize the air intake design using the latest computer technology and then build the one that has the best performance.

Despite the usefulness of CFD analysis in optimizing intake design, the main application of STAR-CCM+ at MSU is external aerodynamics.

“The main purpose for using STAR-CCM+ is to reduce the aerodynamic drag while increasing the downforce, or at least keeping it constant. This year we are specifically focusing on optimizing the sidepods as they are one of the biggest contributors to the aerodynamic drag” says James Guitar, head of Aerody-namics. “The sidepod optimization includes the positioning of the radiators as well as finding suitable location and size of the openings to ensure that there is an even distribution of pressure across the face of the radiator and no reverse airflow inside the sidepods themselves.”

“We are also paying great attention to the undertray design, the main purpose of which is to reduce turbulence under the car and, by extension, reduce the aerodynamic drag.” The undertray design features two expanding tunnels in the shape of a diffuser that twist between the driver, engine and rear tires. The tunnel size, diffuser angle of attack and inlet-outlet ratio are determined using STAR-CCM+ taking into consideration packaging constraints and the ground effect. “We are hoping to make a significant increase in the level of downforce. We find STAR-CCM+ very intuitive, easy to learn and implement which enabled us to make a number of design changes in the early stages of the software implementation.”

The Formula SAE race cars are usually made of steel tubular frame to which the engine sub-frame, bodywork and suspension members are attached. Calculating the flow around the car was traditionally very difficult, as it often consisted of many small details and “dirty” CAD data containing poorly triangulated, overlapping or disconnected surfaces. To repair these surfaces manually would consume many man-hours of stiching and repair in order

to obtain a high enough quality surface mesh required for CFD analysis. In STAR-CCM+, this task can be achieved automatically by simply deploying the surface wrapping tool. “We are particularly happy with automated meshing capabilities of STAR-CCM+, it greatly reduces simulation set up time for the multiple geometry configurations that we are analyzing.”

The standard k-epsilon model was applied, and the steady state flow around the car was simulated in order to properly resolve the flow under the car, the moving floor and rotating wheels were set as boundary conditions. The model consisted of approximately one million trimmed cells with prismatic layers strategically located in the zones of high pressure and velocity gradients. To help resolve the flow features around the complicated car geometry, volume refinements were used.

As well as the aerodynamic analysis of the car, STAR-CCM+ was also used to model sloshing in the fuel tank using the Volume of Fluid (VoF) model helping the MSU students predict liquid movement in the fuel tank and engine oil pan while the car experiences high inertial forces in corners or during acceleration and braking. As the fuel and engine oil are pulled away from pumps, careful fuel reservoir and engine sump design prevents starvation of these fluids enabling maximum engine power and proper lubrication of moving parts inside the engine.

“STAR-CCM+ has really opened up a new realm of possibilities for our car”, says Guitar, “being able to use this software for external simulations, restrictor design, oil reservoir and gas tank sloshing will help to improve our vehicles performance and overall design.” <

i MORE INFORMATION ON THE MICHIGAN STATE UNIVERSITY http://www.msu.edu/

Thinking globally is at the heart of MSU’s

dedication to forming partnerships with institutions

around the world that share our commitment to

enhance education, health, agriculture, business,

and technology.

As the world grows smaller, the university’s

reputation as a leader and sought-after partner in

international academia, research, and economic

development becomes ever more vital.

View your local course offerings, customer testimonials and register for an upcoming course at: www.cd-adapco.com/training.

To register for a course: Complete the online registration (www.cd-adapco.com/training) or request a faxable form from your training administrator:uSA: [email protected] (+1) 734 453 2100 uK: [email protected] (+44) 020 7471 6200Germany: [email protected] (+49) 911 946433 France: [email protected] (+33) 141 837560Italy: [email protected] (+39) 011 562 2194

Specialized courses:New specialized courses relating to application specific areas are developed throughout the year. Check for these courses at: www.cd-adapco.com/training

STAr-Tutor online Training:STAR-Tutor is a virtual classroom that enables you to learn more about CFD and CD-adapco’s solutions, wherever you are. Whether you are new to CFD, using simulation in a new application area, or picking up a CD-adapco tool for the first time, STAR-Tutor can get you up to speed, fast. STAR-Tutor’s innovative format allows you to fit personal development training around your schedule. To view the STAR-Tutor schedule and course list, please visit: www.cd-adapco.com/training/STAr-Tutor

note: In most situations it will be possible to register trainees on the course of their choice. However, if requests for places on courses are received too close to the course date, this may not be possible. Availability of places can be obtained by contacting your local office. See our website for most up to date schedules and registration. www.cd-adapco.com/training

Choose from Courses Including:• Foundation Training • STAR-CCM+ Foundation• STAR-CD Foundation• STAR-Design• Advanced STAR-CCM+• Advanced STAR-CD

• Advanced Meshing• Advanced Modeling• User Subroutines• Spray & Combustion• E2P• Virtual Tow Tank

• Effective Heat Transfer• Simulation of Rigid Body Motion for Engineering Analysis• Engineering Process Automation through JAVA Scripting

AND MORE...

Training adds incredible value to the software you have purchased and comes highly recommended by all. courses are regularly held at cd-adapco offices around the world including: detroit, houston, Seattle, London, nürnburg, Paris, Turin and others. The courses listed on our website can be scheduled to suit your requirements. To take advantage of this, please request information from your local training administrator.

TrAInInG VEnuESdetroit, united Stateshouston, united StatesSeattle, united StatesLondon, united Kingdomnürnberg, GermanyParis, FranceTurin, ItalyBangalore, India

Training courses


..::TrAInInG

automotive special report

Documents