Evaluating FSAE aerodynamics 2013 event report Alternatives for a ...

Leading-Edge Motorsport Technology Since 1990Formula Student 2013 • www.racecar-engineering.comDIGITAL SPECIALFormula StudentEvaluating FSAEaerodynamics2013 event reportAlternatives for aspaceframe chassis

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CONTENTS – FORMULA STUDENT EDITIONSustainable racingHistory was made at the 2013 FormulaStudent UK competition at Silverstone asan electric car took overall victory for thefirst time. This result can be read one oftwo ways; either electric is the future forFormula Student, and needs to be embracedby all teams that have ideas about winning,or that the categories need to change. Inother competitions, electric cars are classedseparately, but that brings its own problems- why would a team invest so much money inthis new technology if it is only for a class win?There needs to be a compromise. Inthis special edition, we also discuss theincreasing presence of carbon chassis into thecompetition. Motor racing is expensive, andwill never be cheap, and some may argue thatit is better to explore these new technologiesat the Formula Student level of competitionthan wait until graduates are exposed inprofessional motorsport to this technology.Yet there is a sustainability issue here - topteams have turned towards major motormanufacturers to help them prepare for thecompetition, both with composites and withhybrid technology. That sort of backing is notwidely available, and raises the spectre of thehaves and the have nots.Should the marketing departments be putto use to put together sales pitches to thesecompanies? After all, for the competition toreplicate the reality of motor sport, being ableto lay hands on money is key to success.It boils down to the point of FormulaStudent, a valuable competition in an ever morecompetitive and expensive world. Is it to trainengineers to find innovative solutions, or is itto train them to work in motor racing?For me, it should be the former. That doesnot mean that students shouldn’t exploreelectric systems and carbon chassis, but thereshould be other solutions. Motor racing is aboutto go through a change; it is no longer onlyabout raw power, it is about fuel economy,weight and reliability. Also, increasingly, motorracing teams are finding lucrative fundingsources from outside motorsport (look atWilliams Hybrid, Zytek and McLaren).Hybrid systems are undoubtedly one partof the solution, but they do not solve ourcrisis. Look at Gordon Murray’s city car, or readProfessor Andrew Graves’ book ‘Build to order- the road to the 5 day car’. In the businesspresentation of the competition, sustainabilityis a critical feature of the scoring and for goodreason. Motor racing will not continue forever,or even for long, if it is not relevant.Carbon Hybrid chassisThe alternative to a steel tube spaceframe chassis - welook at whether or not it worksAerobytesWe put a Formula Student car in the wind tunnel, and letthe students run the programmeElectric shockElectric cars dominate the Formula Student UKcompetition for the first timeEV Motor technologyThe latest alloys used in motorsGetting a job with MercedesMercedes High Performance Powertrains uses FormulaStudent to recruit the best new thinkers, and puts themto work on its latest F1 engineSave Formula StudentOne of our readers takes exception to the way in whichthe competition is developingSubscribe to Racecar Engineering – find the best offers onlinewww.racecar-engineering.comFormula Student supplement • www.racecar-engineering.com

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TECHNOLOGY – TUBULAR FRAMESPerfecting thespaceframe chassisIt's been written that the spaceframe chassis has been optimised.It hasn’t, says one former Coventry University studentThe hybrid spaceframe has atorsional rigidity of 4,450Nm,which is over four times greaterthan the steel spaceframe that itwas designed to replace. Therewere negligible weight savingsdue to constraints on materialdimensions, although the specificstrength of a hybrid spaceframeis significantly higherThe tubular steel chassisis not fashionableany more. These daysalmost every youngengineer wants to use advancedcomposite materials like carbonfibre to design their new car.They even turn their noses upat the use of a tubular chassis.They argue that steel chassisare heavy, lack rigidity andare not as safe as compositemonocoques. Those in favour ofthe tubular steel chassis arguethat the ‘spaceframe’ is cheap,easy to manufacture, easy torepair and highly versatile.But one student at CoventryUniversity in England wonderedif it would be possible to getthe best of both worlds.Replicating the thoughts of manylow-cost formula car designersover the years, such as thosebehind the British-built RossaliniFV391 Formula Vee, could hereplace at least some of thesteel with readily availablecomposite tubing?Giorgio Demetriou tookhis university’s 2012 FormulaStudent car design (a steeltube frame) and investigatedconverting the design into whathe calls a hybrid spaceframe. Theresults are relevant to anyonedesigning or building cars in anopen rules environment, such asFormula Ford, Vee or a numberof SCCA classes.‘I aimed to develop a chassiswhich is competitive withcomposite monocoques usedin Formula Student, but whichcould be manufactured forsubstantially less cost in ashorter timeframe,’ explainsDemetriou. ‘I realised quicklythat there were two key pointsto address: the use of tubularcarbon fibre in spaceframeconstruction and the applicationof direct metal laser sinteringas a manufacturing process tocreate connection nodes.’One of the key points of theproject was that Demetriou andthe other Coventry studentsdid not want to modify theexisting design in any way,leaving the hard points andgeometries as they were.‘Spaceframes have been usedfor many decades, and as a resultmuch research and testing hasgone into the optimised design.An ideal framework would consistof only struts and ties, pin jointedand loaded at the joints,’ addsDemetriou. ‘It could be arguedthat tubular chassis design hasbeen completely optimised,and literature has been writtento this effect. The design of aspaceframe chassis is unique toeach vehicle and each will pose anew set of packaging constraints.A good spaceframe will receiveTable 1: carbon tube selectionTube Material OD Wall ThicknessBaseline 1 Steel 25.4mm 1.6mmBaseline 2 Steel 25.4mm 1.25mmReplacement 1 CFRP 28mm 1.84mmReplacement 2 CFRP 26mm 1.56mmFormula Student supplement • www.racecar-engineering.com

TECHNOLOGY – TUBULAR FRAMESEQUATIONS!"#$%"&' !"#$%&' !"#$ (!! ! ) = 32! ! !"#$%h(!!) !"#$%&'( !"#$%&' !"#$ !! !∴ !"#$% !"#$ !! != 36.8! ! !"#$%h (!!) = !"#$%"&' !"#$%&' !"#$ + !"#$%&'( !"#$%&' !"#$ !"h!"#$! !"#$% !h!"# !"#$% = !"#$% !"#$ ! !"h!"#$! !h!"# !"#$%&"h!!! ! The required Joint Shear Force was to be equal to the force required to take a baseline steel tube beyond its elastic limit. This force was calculated, using the below formula, as 18.8KN. !"#$$ !"#$%&'() !"#$ (!! ! ) = !! ! ! − !! ! ! = 62!! ! !"#$% !"#$% ! = !"#$% !"#$!"#h= 18.8!" Figure 1: FSAE chassic comparison!!! ! ! !"#$$ !"#$%&'() !"#$ (!!! )tubes were 68 and 75 per centrespectively. These savings,however, don’t include the massof a metallic node.‘Due to the sponsor onlyoffering us a specific type oftube with 36.8mm OD and32mm ID, we were a bit limited inthe real world,’ says Demetriou.‘This tube only provided a 46and 45 per cent weight savingand was over-specified by afactor of 3-4 in terms of strength.The other major impact of theincreased tube diameter wasthat the floor thickness wouldconsequently change. Thatwould have a big impact onthe damper mounts on theCoventry car which areincorporated into the floor.With an increased diameter ofthe floor rails, it would not havebeen possible to use the samemounts or floor.’loads directly into nodes anddistribute these throughoutthe chassis, causing minimaldistortion to any of the members.’The ethos of the CoventryUniversity 2012 FS Vehiclewas ‘lightweightness’, whichrestricted the quantity oftubing that could be used toconstruct the chassis. Therewas a balance to be foundbetween torsional rigidity andmass. Collected data for variousFormula Student vehicles can beseen in Figure 1 above, whichshows mass vs rigidity.Demetriou wondered ifthe same stiffness could beachieved for less mass by usingoff the shelf carbon fibretubes, which are relatively lowcost and readily available. Herealised that he would haveto overcome the metal-tocompositebonding challenge,and went on to investigate howthe concept would impact the2012 Coventry car.The Carbon Fibre tubes weresponsored by Exel Compositeswww.racecar-engineering.com • Formula Student supplementUK and were to be from theirExelite range of high strengthtubes. A spreadsheet wascreated which utilised macrosto derive wall thickness. Thisallowed the outside diameterof a tube to be specified,due to compact packagingconstraints, while the wallthickness was varied. Thespreadsheet also had the abilityto display the mass of each tubeand thus derive the percentageweight saving between the twotubes. Savings for equivalentSTEEL OR COMPOSITE?Despite this, Demetriou managedto complete the modified hybriddesign, which can be seen(see Table 1, p61) showing thatwhile some steel memberscould be replaced by compositetubes, not all of them could be.However, in many cases, thiswas due to the lack of choicein carbon tube availability toCoventry, and in reality wouldnot be a major concern.The bulkhead needed toremain in steel to accommodatethe mandatory FSAE crashbox.The design of the Coventrycrashbox was such that itrequired the anti-intrusionplate to be welded, around itsperimeter, to the frame. Witha carbon frame an alternativemethod of attaching the platewould be required.As previously explained, anyincrease in the diameter of thetubing would not accommodatethe existing hardware for thedamper mounts. There would alsohave been an issue regardingground clearance – the bottom ofthe spaceframe would be 11mmlower, plus the depth of a nodecausing the vehicle to groundout when experiencing heave orsingle-wheel bump.The pull rod used for the'A good spaceframe will receive loads directly into nodes anddistribute them throughout the chassis with minimal distortion'

front suspension operated alongan arc, which avoided a clashwith the diagonal member (atpoint four) by 2mm as full bump/rebound. Increasing the diameterof the tube to 36.8mm wouldcreate a bending moment at thepoint of clash, causing the pullrod to catastrophically fail. In asimilar fashion, both the lowerand upper rear wishbones wouldfoul on the rear bracing supportsif the diameter of the tube wasincreased to beyond 26mm. Thewider tubes also meant that theFSAE mandated cockpit templatewould not fit, so the cockpitsurround remained in steel.The next challenge waswhat to make the nodes outof and how to attach them toboth the composites and theremaining steel chassis elements.Titanium has the greateststrength per unit of mass,although mechanical propertiesalone cannot be viewed inisolation when deciding nodematerial. FSAE regulationsstate that: ‘alternative tubinggeometry and/or materials maybe used except that the MainRoll Hoop and Main Roll HoopBracing must be made fromsteel, ie the use of aluminiumor titanium tubing or compositesfor these components isprohibited.’ This presented threepossible methods of attaching anode to the Roll Hoops:AdhesivesMechanical JointWeldingAn adhesive connectionwas designed, although it wasdeemed to be too high risk. Itwas thought that welding steeland stainless steel would bethe most reliable method ofjoining the nodes to the rollhoops. However there is up toa 35 per cent reduction in yieldstrength when welding steel. Thetemperatures required to rework(Post Welding Re-annealing)under 300degC would damagethe carbon and adhesive, so thisprocess could not be used. Soeventually Demetriou decidedthat a mechanical joint wouldbe the simplest method ofattachment, although adhesiveswould replace any bolts. Theaddition of a bolt and the extramaterial used to create thenode greatly increased theoverall weight.A spaceframe chassiscomprises of only ties andstruts in tension or compression.The design of the node socketrestrains a carbon tube in sucha way that it cannot translatealong its axis, thus removing anyshear loading on the adhesiveduring compression.The tensile forces actingon a member are resisted bythe adhesive; creating a shearstress. By using ALM (AdditiveLayer Manufacturing), it ispossible to grow small arrowshapedpins on to the surface ofthe metal part, which embeddedinto a carbon fibre part canprovide a tough and durable joint.The principle of incorporatingmechanical ‘pins’ to reinforcea chemical joint in shear hasbeen applied to the node ends.An alternative method ofmanufacturing a mechanicaljoint was creating cavitiesby allowing adhesive to flowthrough the substrate to forman adhesive pin, illustrated bythe yellow region seen in theimage above.The ideal dimensions ofthe node end would be 0.5mmlarger/smaller than the carbontube, with the ‘pip’ keeping thetube concentric and controllingthe bond gap. The dimensionsof the socket were dictatedOne of the key elements of the chassis concept was the adhesivejoint, which utilised small holes in the nodes to form an adhesivepin (seen above in yellow). These were the actual reason for theproject not seeing fruition. Formula Student judges did not feel thatan adhesive joint could be visually inspected. Giorgio Demitriouargued that you could indeed visually inspect such a joint, and offeredempirical test data, but the decision went against himby the internal and externaldiameters of the carbon tubes,and to compensate for anymanufacturing errors in thetube, the size was made toaccommodate a tube furthestfrom specification as per themanufacturers tolerances.The length of the socketswould dictate the surface areaof the node socket, thus definingthe bonding surface area andthe resultant joint strength. Aspreadsheet was created whichcomputed the minimum socketlength required to producethe necessary bond area. Thespreadsheet caters for differentadhesives and baseline materialdimensions and mechanicalproperties. This allowedretrospective changes to be madeto calculations, should full-scaleadhesive testing results varyfrom scale testing.But as anyone who has putup a modern dome tent knows,arranging a set of compositetubes and nodes is not alwaysstraightforward. Indeed, with'The temperatures required to rework steel would damage the carbonand adhesive, so this method of joining the nodes was rejected'Formula Student supplement • www.racecar-engineering.com

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TECHNOLOGY – TUBULAR FRAMESthe Coventry design it wasimpossible. Demetriou foundthat it would not be possible toslide multiple tubes into positionas each tube/socket alignedalong a different axis. Thesolution that the team createdwas to fabricate the chassis insegments, which couldthen be welded together.Meanwhile, the steel segmentof the spaceframe wouldonly be tack-welded duringassembly to allow for the someflex in the members, permittingthe internal shapes of the nodesto locate on to the internal facesof the tubes.Even once the manufactureand design of the hybridspaceframe had been workedout, the question remained:could the composite tubestake the load? A failure in anyof the tubes when the chassiswas at speed would likely becatastrophic in more ways thanone. Extensive simulation workconducted by the Coventrystudents suggested all wouldLOAD TRANSFER AND ROLL STIFFNESSAn investigation by TheUniversity of Leeds’ School ofMechanical Engineering wasable to determine the chassisstiffness that ensures thevehicle’s handling is sufficientlysensitive to changes in theroll stiffness distribution. ‘Ifa vehicle has a 50:50 weightdistribution, with a 50 per centroll stiffness distribution, it isthe case that no load transferis required,’ they said. This isan idealised and unfeasiblescenario, but serves as a usefulexample for the inverse. If anunbalanced vehicle has a largeroll stiffness distribution, thenthe chassis is required to becapable of transferring largeloads, achieved through hightorsional rigidity.The total roll stiffness –defined as ‘the sum of frontand rear roll stiffnesses’ – canbe viewed as a multiplierwhen selecting a chassistorsional rigidity. A vehicle ismore sensitive to roll stiffnessdistribution and torsionalrigidity as the total roll stiffnessincreases. The diagram belowshows the results from asimulation by Deakin for a 50:50weight distribution vehicle, withtotal roll stiffness of 15,000Nmusing varying chassis stiffnesses.It can be seen that if a 40:60roll stiffness distribution wasrequired, then a disproportionallylarge percentage change of rollstiffness is required to achievethe target when using thesofter chassis. For example, toachieve a 40:60 distributionwith a 300Nm/degree chassis,an 8:92 roll stiffness distributionis needed. The weakest chassis(100Nm/deg) was not able totransfer the required load.The above figure showsthat with significantly lowerroll stiffness, the chassiswhich have a lower stiffnessbe fine, but it relied on a numberof assumptions. ‘With minimaldata it was crucial to completephysical testing to characterisethe material to refine the limitedFEA and verify theoreticalvalues,’ admits Demetriou. ‘Theonly provided value for thetubes was to have a stiffness of100MPa, although an orientationwas not specified.’Unfortunately, a proposedpartnership to manufacture thenodes between the Coventryteam and a German firm fellare still responsive to changesin roll stiffness distribution.All but the weakest of chassis(100Nm/Deg) was able toprovide the required loadtransfer with all above600Nm/Deg having an almostlinear relationship.The most crucial valueused to decide the stiffnessof a chassis is total rollstiffness as the non-linearrelationship between rollstiffness distribution and loadtransfer worsens with higherroll stiffnesses. The natureof Formula Student createslightweight vehicles which tendto have roll stiffnesses below700Nm/Deg. Given that FSAEregulations insist on manysafety tubes of given dimension,it is not physically possible tocreate a chassis which will beunresponsive to changes inroll stiffness distribution, forexample below 300Nm/Deg.through. This meant that thehybrid chassis was nevercompleted, and the physicaltesting did not take place.But the design resultsshowed great promise. A keycriteria used to measure thesuccess of the project wastotal chassis mass. The mostbasic of hybrid members hada total mass of 0.502kg,almost half of the equivalentsteel tube (0.920kg). But theoverall chassis weight savingwas insignificant. The total massof the original steel spaceframewas 26.2kg, not including thefloor or bulkhead. The hybridspaceframe had a calculatedmass of 25.1kg, not including theadhesives. This is a total weightsaving of 1.1kg, or 4 per cent.BULKY PACKAGING‘The relatively insignificantweight savings are due tothe over-sized carbon tubes,’explains Demetriou. ‘Althoughthe tubes still had 50 per centless mass than the steel tubes,the packing of a 36.8mm tubecreated much larger and bulkiernodes, compared to one whichwas designed to accommodatea thinner tube. The mostpertinent conclusion to makefrom my work is that tubularcarbon fibre can be used tomanufacture a spaceframechassis, and that nodes are asimple and effective methodof joining composite members.The scope for a carbonspaceframe, outside of FSAE,is vast and the ability to startfrom a blank sheet with design,as opposed to producing areplacement for an existingspaceframe, further extendsthe scope. The strength andweight advantages of carbontubing, compared to steel, areconsiderable and without themandated use of steel for rollhoops, further weight savingscan be made.‘Carbon tubes are available inan almost infinite array of sizes,’concludes Demetriou. ‘Thereis no reason why the lessonslearnt from this project cannot beextended to larger vehicles.’Giorgio's thanks go to James Jarvis,Mark Ali Akbar, Stuart Jacksonof EOS, and Mark Stewart ofDassault Systemes LtdFormula Student supplement 2013 • www.racecar-engineering.com

SPECIAL SUBSCRIPTION OFFER - STUDENT RATEBETTER THANHALF PRICEGET THE NEXT 3 ISSUESOF INSIGHT, EXPERTOPINION AND TRACK-SIDE KNOWLEDGE FROMRACECAR ENGINEERING FORJUST £3!Each month, Racecar Engineering bringsyou the best possible insight into allforms of the continually changing worldof motorsport engineering. From keepingpace with the latest technologies toexpanding your knowledge of racecardesign and operation, no magazine getsyou closer.IN EVERY ISSUE:• Latest news, cars and results• Technical insight and analysis• Engineering solutions explained• New products and innovations• Expert commentary and debateRacecar Engineering Volume 23 Fuels revolution Porsche 911 RSR Aston Martin Rapide SJuly 20137Leading-Edge Motorsport Technology Since 1990July 2013 • Vol23 No7 • www.racecar-engineering.com • UK £5.50 • US $13.50Porsche 911 RSRtackles the GT world8Racecar Engineering Volume 23 Formula E launch Red Bull RB9 Wind tunnel tyresNovember 201311Formula 1 2014Leading-Edge Motorsport Technology Since 1990We uncover the challenges facingengine designers next yearNovember 2013 • Vol23 No11 • www.racecar-engineering.com • UK £5.50 • US $13.50Red BullRB9Aston Martin Audi’s V6 engine Fuels of the futureHydrogen-powered Rapide Open-source data of the A sustainable solution tocompletes Nürburgring 24 R18 Le Mans powerplant the fossil fuel dilemma?RCE Cover July.indd 1 22/05/2013 11:33Adrian Newey discussesthe F1 title favouritePLUSFormula E revealedThe future ofGrand Prix enginesWind tunnel tyredevelopmentPeter Wright onthe Nissan ZEODRacecar Engineering Volume 23 Nissan ZEOD Garage 56 Renault Energy F1 Rapid prototypingAugust 2013SRT Viper GT3US manufacturer’s newmodel for the global marketLeading-Edge Motorsport Technology Since 1990August 2013 • Vol23 No8 • www.racecar-engineering.com • UK £5.50 • US $13.500 79 7 7 0 9 6 1 1 0 9 0 9 8Nissan targets 300km/h onelectric energy at Le MansRapid prototypingThe long-term future of adeveloping technologyRCE Cover August.indd 1 28/06/2013 15:061 19 7 7 0 9 6 1 1 0 9 0 9 80 89 7 7 0 9 6 1 1 0 9 0 9 8RCE Nov Cover.indd 1 23/09/2013 14:43SPECIAL STUDENT RATESUBSCRIBE TODAY8)www.chelseamagazines.com/racecar-FS3X+44 (0) 1795 419 837 quoting FS3XDirect Debit orders only

TECHNOLOGY – AEROBYTESStudents unleashedUniversity of Hertfordshire Formula Student team won a windtunnel session, courtesy of the IMechE and Racecar EngineeringSimon McBeath offersaerodynamic advisoryservices under his ownbrand of SMAerotechniques – www.sm-aerotechniques.co.uk.In these pages he usesdata from MIRA to discusscommon aerodynamicissues faced byracecar engineersProduced in association withMIRA LtdTel: +44 (0) 24-7635 5000Email: enquiries@mira.co.ukWebsite: www.mira.co.ukRecent trends have seen theblossoming of wings andother downforce-inducingparaphernalia in Formula Studentworldwide. How significant arethese developments? To answerthat question, Racecar Engineeringprovided a half day session inthe MIRA full-scale wind tunnelto the team that the Institutionof Mechanical Engineers andRacecar Engineering, judgedto have the best publicity andon-event presence in the 2013Formula Student competition.The winner was the University ofHertfordshire.This was the first year thatthe University of Hertfordshire,which has been involved inthe competition since 1998,had entered a car with a fullaerodynamics package, althoughaerodynamic designs had beenworked on in previous years.Analysing the overall performanceof its 2012 contender, UH15,the team, comprising 11 MEngstudents and 35 other members,decided that the only way tomake up the three second lap timedeficit in the sprint competitionwas with aerodynamics. Anaerodynamics group was formedunder managers Sam Bloodand Karl Mackle, who reportto technical director AntonioCarrozza, and manufacturingmanager and head of chassisdevelopment Matt Grant.The first aerodynamic packagedevised for the 2013 competitionscomprised front and rear highdownforce wings, with Bloodtackling the rear wing design anddevelopment, and Karl Macklethe front wing. It was decidedto utilise pre-existing aerofoilprofiles with coordinates in thepublic domain, rather than spendtime on bespoke profile design.A shortlist of candidates waswhittled down with the help ofStar CCM+ CFD software to theSelig1223 ‘high lift’ profile forthe main elements and flaps,front and rear. The decision to runwith dual-element wings frontand rear for this first iterationwas taken on the practical basisthat this configuration requiredjust one slot gap over the wideadjustment range to optimise thesprint, endurance and accelerationphases of the competition, eventhough a triple-element (or more)the team decided that the only way to make up thethree second deficit was with aerodynamicsPreparations for the sessionconfiguration offered greaterdownforce potential. CFD wasused to establish the optimalrelative positions and angles ofthe main elements and flaps,and also end plate size and shape.Cost and time considerationswere also involved in the choiceof configuration and overallpackage design, as indeed wereoverall car design changessimultaneously underway.The planned quarter scalewind tunnel test of UH16, withwing package in the University ofHertfordshire’s own wind tunnel,unfortunately didn’t happenbecause of time constraints, apartfrom some runs on the wingsections only, which comparedreasonably favourably with theCFD data. So, the MIRA test wasthe first opportunity to derivesome hard data on the firstintegrated aero package.MIRA dAtAAs ever we should restate thatMIRA’s full-scale wind tunnelhas a fixed floor and the testcar’s wheels are stationary. Thefixed floor tends to underestimatethe downforce generated byground-effect devices, includingfront wings. However, with the‘boundary layer control fence’installed and with no downforceinducingunderbody on the car,overall under-estimates wouldbe relatively minor, and reardownforce and drag would havebeen accurately determined.So, how did the car perform?Table 1 shows the data in thebaseline configuration (maximumwing angles all round) at just40mph and 60mph. As usual,and of especial interest in thisapplication because of the veryrelevant speed range of theFormula Student competition’sdynamic phases, the car was runat two speeds to see if there weredifferences in the coefficients,and the data is shown in Table2, together with the differencesbetween the two speeds.Formula Student supplement • www.racecar-engineering.com 51

TECHNOLOGY – AEROBYTESThe first iteration full aero package comprised front and rear dualelementwing setSetting up the split front wing flaps to maximumThe front wing’s upwash could be seen to encounter the rear wing’s flow fieldFlows around the front wing end plate came in for close examinationThe first observations tomake are that although the dragcoefficient was rather high, theoverall negative lift coefficientwas even higher, producing anefficiency figure, -L/D, of over1.5. Out of interest, comparingthis with other open wheel singleseaters tested for this column,the Formula Student data is partway between the aerodynamicperformance of an early 1980s‘flat bottomed’ Formula 1 car andthe more modern ones we havetested, a 1999 Benetton and a2007 Honda.Of significance, though, arethe differences between thecoefficients at 40mph and 60mph.Aerodynamic forces normallyincrease with the square of speedso, all other things being equal,the calculated coefficients derivedfrom the logged force data wouldbe the same at the two differentspeeds. For the coefficients tovary with speed, all other thingsTable 1 – baseline data at 40mph and 60mph, with thedifferences in ‘counts’ where 1 count = a coefficient change of0.001CD -CL -CLfront -CLrear %front -L/D40mph 1.158 1.758 0.980 0.778 55.7 1.51860mph 1.146 1.797 1.055 0.742 58.7 1.568Difference -12 +39 +75 -36 +3.0 +50Table 2 – overall drag and lift forces in baseline configuration,with downforce as a percentage of static weightDrag, N -Lift, N % of weight40mph 244.7 370.2 12.9%60mph 515.6 805.2 28.0%were not equal. This is not anunusual situation, with theflows over (or more often, under)downforce-inducing surfaces notbeing fully developed at speedsas low as 40mph. In this instance,what we see in the results isthat the front lift coefficientincreased by 7.7% from 40mph to60mph, leading to the conclusionthat the flow was betterdeveloped (for which read ‘betterattached’) at the higher speed.Remember, all the flaps wereat their maximum angles in thisbaseline configuration, andthis may have been too steepfor the flow to be adequatelyattached to the front flaps at40mph. Wool tufts on the flapundersides confirmed that theseflows were not fully attached, andthat the higher speed showedimproved attachment.It will also be noted that therear lift coefficient decreasedslightly at the higher speed.This could have been the resultof any improvements in flowattachment at the rear beingsmall enough to be masked by theincreased mechanical leverageahead of the front wheels arisingfrom the improved front wingperformance. This slightly offloadsthe rear wheels. Or it could havebeen the consequence of theupwash of the wake arisingfrom improved front wing flapattachment encountering therear wing more than previously,thereby slightly reducing itsaerodynamic performance. Theactual mechanisms are best leftto CFD; the wind tunnel simplyreports the results measured atthe wheels. But the fact that thedrag coefficient also decreased,something that is known to occurwhen a rear wing angle is reducedfor example, suggests there maywww.racecar-engineering.com • Formula Student supplement

Tip vortices created the usual fascination at front…… and at the rearCooling flows were also examinedWing flow attachment was visualised with smoke and wool tuftshave been an actual aerodynamicinteraction here as well as amechanical one.The net result of the frontgains and rear losses was a 3%shift in balance to the front from40mph to 60mph, something thatmight be felt by the driver if thetrack contained corners or brakingareas taken at the two differentspeeds. Of more significance,though, is that for a car with a50/50 static weight balance, theaerodynamic balance was forwardbiased even at 40mph, this aspectworsening at 60mph, whichwould make the rear more skittishas speeds increased, provokingsome instability under braking, oroversteer in faster corners if thechassis was mechanically balancedat lower speeds.It’s all relatIve…The extent of the influence ofaerodynamics on handling andgrip does depend, though, on theTable 3 – aerodynamic forces measured in MIRA at 60mphon the 2012 Dallara F3, and the 2007 Honda F1 withbargeboards removedDrag, N -Lift, N % of weightF3, 2012 343.0 841.1 Approx. 14%F1, 2007* 530.5 803.3 Approx. 13%*Bargeboards removedmagnitude of the aerodynamicforces relative to the car’s weight.So, let’s look at the actual forcesin that context. Table 2 showsthe overall drag and lift forcescompared to static weight.Thus, at 40mph, the downforcewas 12.9% of the car’s weight,and at 60mph had risen to 28.0%of the car’s weight. At thesespeeds, these are fairly significantincreases in the vertical forcesacting through the tyres. (To gooff on a tangent for a second - anirresistible calculation at this pointis to work out the speed at whichthe car generates downforce equalto its own weight, at which speedit could drive across the ceiling,and it comes to 113.4mph!).It is never a good idea tocompare the data from cars indifferent categories except outof passing interest, but this alsooften proves irresistible…Table 3speaks for itself.The levels of absolutedownforce generated at 60mphwas therefore quite similar to theFormula Student’s downforce, butit is the amount relative to carweight that is important, and inthat respect the FStudent waswell ahead! Clearly the F3 car wasmuch more efficient though, with alot less drag being created.Two notes of caution; first, theHonda F1’s downforce was muchgreater with its bargeboards;second, both the F3 and F1 cargenerated a large proportionof their downforce with theirfloors, and as mentioned earlier,MIRA’s fixed floor would lead toa downforce under-estimationof this. Nevertheless thecomparisons are interesting andshow that the Formula Studentcar was able to generate a muchlarger proportion of its weight indownforce at these speeds thaneither the F3 or the F1 car in theguise mentioned.Next month we will look at theresponses to adjustments made inthe wind tunnel by the students.Racecar Engineering extendsits thanks to the staff andstudents at the University ofHertfordshire Formula StudentRacing TeamFormula Student supplement • www.racecar-engineering.com

FORMULA STUDENTElectric shockThe 2013 Formula Student competition made worldwide motorsport history –an electric car beat a combustion car. And the surprises didn’t stop there…There is no doubt thathybrid and electricvehicles are takingcentre-stage inthe modern automotive andmotorsport industries. In 1997, itall started when the Toyota Priusbecame the first mass-producedhybrid vehicle; next was the firstmass produced all-electric vehiclewhich came in the form of theNissan LEAF in 2010. 2012 sawthe first hybrid win at Le Mans bythe Audi R18 e-tron Quattro andin March this year alone, morethan 6.3 million hybrid vehicleswere sold worldwide. This trendwill undoubtedly continue, as2014 becomes more electric thanever with the world’s first electricrace at the launch of Formula E,and the increased usage of hybridpowertrains in Formula 1.by GEMMA HATTONAnd it’s exactly the same forFormula Student.The first electric FormulaStudent car to take part in acompetition is thought to bewhat was called a ‘hybrid inprogress’ (ie electric only),designed by the University ofFlorida for the 2007 FormulaHybrid competition. In the UK thebar was raised higher the sameyear with the introduction of aspecial alternative fuels category,dubbed class 1A. In 2012 it wasdecided to merge the classeswith both conventional andalternative powertrains runningin the same class.At the Silverstone competitionthis year, electric cars madeup 20 per cent of the FormulaStudent field, which at firstseems a relatively smallproportion. However, overall firstand second place were bothwon by electric teams. Themain issue is the extravagantinvestment required for an allelectricconcept, somethingwhich most universities cannotafford. Many teams, when asked,would go electric if they hadMany teams said they would goelectric if they had the funds,manpower and time requiredthe extra funds, manpowerand time required. The ‘electricpercentage’ will undoubtedlyincrease over the coming yearsas more teams compete, theseries becomes more globaland students see the increasedpotential of electric powertrains.Another record-breakingfact for this year’s competition:not only was it the hottestevent held in the UK, but alsothe driest. Sun shades, shortsand regular barbecues madethe paddock almost glamorouscompared to previous years oftrekking around in Wellingtonboots, battling with the wind andrain. Of course, with unexpectedhighs of 28degC (82degF), teamsand their cars now faced anunknown challenge of dealingwith the heat – most teams hadETH Zurich dominated the event with their all-electric car,the first win for an alternative fuelled vehicle in FSAEwww.racecar-engineering.com • Formula Student supplement

completed minimal testing, andthose that did tested for a dayat most in mixed conditions. Itwas going to be an interestingweekend, not least for thoseteams using electric drive. Somewere even seen taping bags ofice to the electric motors aheadof dynamic events in an attemptto keep them cool.The performancecharacteristics of the EVs wereclear from the first dynamicevents. Unsurprisingly, withtorque instantly available, theelectric cars dominated theacceleration event, claimingthe top three positions, withthe University of Stuttgartcoming first, Delft Universityof Technology taking secondand TU Dresden third, after thedisqualification of the car fromKarlsruhe (see p52).The most visually obvioustrend for this year’s cars wasthe integration of advancedaerodynamic packages, and therewere some highly interestingapproaches, particularly forthe acceleration event wherereducing drag is essential. Most ofthe aero-dominant teams eitheradjusted parts of the rear wings,by altering the position of theslats to reduce frontal area, andtherefore drag, or dropped theentire rear wing assembly downto increase top speed. This mayseem an obvious tactic, but toactually implement adjustableaero into a Formula Student carcan be extremely challengingand demonstrates a high level offorward thinking from the teams.It is fair to say that this year’saero designs were the mostextravagant, with the KarlsruheInstitution of Technology teamrunning a full DRS system, whichgained their combustion car sixthplace in acceleration. However,the most striking aero design byfar was the Warsaw team fromPoland which ran two rear wings,a front wing and an underfloor.The same form was repeatedin the sprint with the top threeall being electric. TU Delft comingfirst this time with a fastesttime of 51.365, the Stuttgartcar was close behind at 51.795,and only a tenth of a seconddenied Zurich second place. Theyfinished third.The toughest event is leftuntil last and is the FormulaStudent equivalent of a grandprix. With 22km to complete,including a mandatory stop,driver change and hot restart thecar’s reliability is pushed to itslimits, and with 300 points up forgrabs, completing the endurancediscipline is what every teamworks towards. Every year carsfail, don’t restart or even catchfire which completely changesthe standings. This year, however,with the added factor of theextreme heat, only 21 teamsfinished. That means 68 per centof the cars failed – the highestdropout rate recorded.In the past, the notoriousSilverstone weather has causedThe Warsaw team ran a strikingdesign featuring two rear wings,a front wing and an underfloorhavoc with sudden heavy rain,so for this year’s event, the top10 cars from the sprint eventtook to the track at the sametime in a ‘shoot-out’ to make itfairer, and – unsurprisingly – therewas plenty of drama. The firstteams on track were Zwickau,Karlstad and the University ofBath who were the fastest car,lapping at 65.1 seconds. Afterovertaking Zwickau, Bath thenfound themselves stuck behindTU Graz, who were a few lapsin and ignored three blue flags.Last year’s winning Chalmersstarted their endurance, butonly survived three laps beforea rear left wishbone failure – areal shock for such a popularfront-runner. Next to join wasthe Munich team, with theirmonster rear wing, but their caronly lasted two laps due to adriveshaft problem. Zurich begantheir race, while the Bath carwas next to fail at the driverchangeover when the enginefailed to restart. Karlstadfollowed suit by also retiringAMG’s controversiAl enGineIt is fairly unusual forthe legality of cars to beprotested at Formula Studentor indeed at any FSAE event, butthat’s exactly what happenedthis year. During technicalinspection the event officialssuspected that the studentsof UAS Graz and Karlsruhe hadnot done all of the work onthe engine themselves. Bothteams use an AMG 595cc twindeveloped specifically for FSAEevents. This led to the technicalscrutineers requesting anofficial ruling as to the legalityof the engines fitted to bothcars, specifically in relation tosection IC1.7 of the 2013 ruleswhich states the following:‘Turbochargers or superchargersare allowed if the competitionteam designs the application.Engines that have beendesigned for and originally comeequipped with a turbochargerare not allowed to compete withthe turbo installed.’The concern was that fromthe start of the design process,the engine was designed withthe turbocharger installed andthis is the package fitted to bothcars. It was not clear how muchcontribution was made by thestudents and how much by AMG.The protest committeemet and produced thefollowing conclusions:• The intent of theregulations is that if anengine is purchased with aturbocharger fitted then itshould not be eligible for thecompetition with that turboinstallation, so the teammust design the installationof the turbocharger.• The fact that the engine wasoriginally designed with thisturbocharger should not beconsidered as an issue if theoriginal design was producedby the students.• The main question to answerwas therefore: did the teamdesign the installation of theturbocharger?• After discussion betweenthe protest committee andthe team members andwith feedback from othersources, it was concludedthat the turbochargerinstallation had beendesigned by the team withappropriate levels of adviceand support from AMG etc.So the engines were deemedlegal under the currentregulations, but the informationfrom the protest has beenforwarded to the FSAE rulescommittee to consider futurerules changes which couldaffect the legality of suchengines and whether suchengines conform to the spiritof the regulations. Many inthe paddock have suggestedthat they feel future rulesshould only allow forcommercially available massproductionblocks such as theHonda CBR or entirely studentdeveloped engines.Formula Student supplement • www.racecar-engineering.com

FORMULA STUDENTCOMPOSITE CONTRAVENTIONSTU Delft’s electric car was a much fancied runner, but failed to deliverfrom the race, as the all-famousDelft team came off the startline, but without their new aeropackage. The electric Karlsruhecar joined the track but due topreviously breaking the rules,(see sidebar, p52), their carwas running at a very slow1 min 16 secs per lap. Zwickauwere the first of the top 10to finally complete the event.Meanwhile another previouswinner, Delft, aborted their raceafter a disappointing four laps.The electric Stuttgart car joinedthe drama, but theirs was a shortlivedrace due to steering issueson the first lap. Another one bitthe dust as TU Graz pulled to theside of the track with smoke andsteam billowing out of their car,causing a major hold-up for therest of the teams. The secondcar to cross the line was Zurich,which only left Karlsruhe running,but that car had damage to oneof its motor-gear units. So, out ofthe top 10 of the best FormulaStudent teams in the world, onlytwo finished, which althoughdisappointing, made for a veryinteresting results table.Outside of the top 10shoot-out, the endurance eventcontinued to be just as dramatic.The battle of the Brits continuedas Hertfordshire completed15 laps before an electronicsfailure struck, while OxfordBrookes also dropped outwith a broken exhaust, whichburnt the car’s chassis badly.That left the competitionwide open for the overall bestBrit position.Stuttgart’s combustion carwas one of the few to finish, andOut of the top 10 bestFormula Student teams in theworld, only two finishedcame a close third behind Zurich,which won ahead of Zwickau.After an eventful five daysin Silverstone, the overallwinner was a fight betweenthe two electric machines ofZurich and Zwickau. But withZwickau just behind on fiveout of the eight judged events,Zurich won by 70 points, withthe successful endurance resulthelping Stuttgart Combustion totake third.The top British team onlyfinished 15th, but that was afantastic achievement for theUniversity of Huddersfield –which proves the effectivenessof having a reliable car thatscores consistently. The othersurprises were last year’swinners, Chalmers, finishing 17thand the event favourites, Munichand Karlsruhe electric coming27th and 30th respectively.Iam frustrated by a fewthings from this year’s FSAEcompetitions, but one gripehas been with me for someyears now and I’m fed up ofit! It concerns carbon fibrechassis. For me these are all ofvery bad design indeed, not asengineering objects themselves– indeed some of them are verynice – but as objects designedto fulfil a specific purpose. Inthe rules there is a very clearstatement, indeed it’s ruleA1.2, almost the first rule inthe book: ‘For the purpose ofthe Formula SAE competition,teams are to assume that theywork for a design firm that isdesigning, fabricating, testingand demonstrating a prototypevehicle for the non-professional,weekend, competition market …additional design factors to beconsidered include: aesthetics,cost, ergonomics, maintainability,manufacturability, and reliability.’I have been increasinglyof the opinion that this rule isbeing largely ignored. I havebeen that amateur weekendracer mentioned in the rules,and I know many others. To aman they all say that they wouldnot buy a car with a compositechassis. ‘Too expensive,’ theysay, ‘if you crash it – which ifyou drive like we do you will, alot – you can’t tell how bad thedamage is without specialistequipment. And if you have areally good hit, you’ll probablywrite the chassis off as they arenear impossible to repair.’Further to this, amateurracers look for longevity fromtheir chassis. Formula Ford1600 chassis racing today areoften more than two decadesold – indeed I used to race a1960s Formula Vee chassisagainst 21st-century designs,and it could corner with thebest of them. The life of acomposite chassis is not fullyunderstood, but the consensusin the sport seems to be thatthey are only good for threeor four years before needingeither replacement or majorrepair work. Something else thatmakes them really unrealisticfor the non-professional,weekend, competition market.Students argue that carbonfibre chassis must be the bestroute because ‘that’s what theydo in F1’. They contest that thecomposite tubs are lighter andstiffer. This is certainly true,but they have lost sight of thepoint of the competition. F1teams do not build cars for thenon-professional, weekend,competition market despitethe performances of some paydrivers at the back of the grid.What frustrates me is thatthe design judges in allcompetitions seem to haveforgotten this too, or simplydon’t realise that composite carsdon’t comply with rule A1.2, andwe regularly see carbon chassiscars in the design finals. Yes thecarbon cars with big budgetsare very nice things with goodaesthetics and ergonomics, butto my mind I cannot see howthey can get good points in thedesign competition as they falldown on the cost, maintainability,manufacturability, and reliabilitycriteria. But then I suppose I’mnot a design judge.Sam CollinsThe UAS Dortmundchassis, one of manycomposite-builtmodels on showwww.racecar-engineering.com • Formula Student supplement

OVERALL WINNER: ETH ZuRIcHThis year’s ETH Zurich car featuredfour internal AMZ M3 Ac hubmotors produced from scratch bythe team. They produced the samepower as their predecessor, butcame in at 40 per cent lighterOnce the Karlsruhe electriccar had been disqualifiedfrom two dynamicevents, it is fair to say that thecompetition was essentiallydominated by the team fromSwitzerland. Its neat electriccar impressed many includingthe design judges, winning thatevent. The major developmentfor the electric teams this yearwas the integration of fourwheel drive, which Sven Rohner,ETH Zurich’s team leaderexplains. ‘This year we focusedon our drivetrain concept. Wechanged it from last year’s rearwheel drive to a four wheeldrive system, which is a majorchallenge because not onlydo we have more motors, butmore electrical components andtherefore more noise withinthe communication lines.’ Lastyear, Zurich ran two outer runAC hub motors, whereas thisyear’s car features four internalAMZ M3 AC hub motors whichwere entirely made by the team.Weighing in at 5kg, the newdesigns produce the same poweras the previous model (32kW)but are 40 per cent lighter.‘The motors are something weare really proud of becausewe started with a white pieceof paper and developed theelectrical and the mechanicalaspects, which allowed us toalter the moment curves andgenerate efficient designs.’Composite chassis remaincontroversial in FSAE, andmany consider them to beoutside of the spirit of thecompetition, but the Swiss teamhas been running carbon fibremonocoques since 2008, andRohner believes that is the rightchoice, ‘F1 use carbon fibremonocoques and it is possible torepair because if you know fromthe beginning then you makedecisions when designing otherparts to accommodate repair.Also, as it is naturally stifferthan a normal steel spaceframe,monocoques are the way togo for increased performance.’Due to implementing the hubmotors, the surface area ofthe chassis could be reduced,allowing the chassis weight tobe reduced by 13.3kg.Another weight savingmeasure is the use ofcomposites in the wheel rims.While far from unique in FSAE,the Swiss designs are veryneat indeed. ‘They are singlepiece and weigh around 850g– one of the lightest in FormulaStudent. If compared to commonaluminium shells, our rims are"The composite wheel rims are single piece, weighing around 850g"Formula Student supplement • www.racecar-engineering.com

FORMULA STUDENTOVERALL WINNER: ETH ZuRIcH (continued)TEcH SPEcLength: 2930mmWidth: 1410mmHeight: 1550mmWheelbase: 1240mmTrack: 1200/1160mmWeight – no driver: -170kgWeight – distribution includingdriver: 107kg/131kgSuspension: Double unequallength A-arm. Pushrod actuatedhorizontally oriented air springsand oil dampersTyres: 18.0x6.0-10 HoosierLC0/R25BWheels: 6.5-inch single-piece CFRPBrakes: Floated, hub mounted,190mm dia., water-jet cutchassis construction: Single-pieceCFRP monocoqueEngine: 4xAMZ M3 electric motorless than half the weight, yetdouble the stiffness and haveincreased yield strength.’ Ofcourse, with the integrated gearand hub motor on a 10-inchwheel, space is somewhatrestricted. ‘It is really on theedge and tight in there, whichis another advantage of ourself-developed rims,’ saysRohner, ‘because we can designit to be stiffer, to allow us to goa little tighter – something wewouldn’t have been able to dowith aluminium shells.’Like most of the top carsin the 2013 competition,the ETH Zurich car featureslarge wings, and the trendtowards downforce-generatingdevices has come as no surpriseto the Swiss students – it wasthe first team to fit wings to anelectric FSAE car. ‘Last year, aerowas more of a “nice to have”feature,’ Rohner adds. ‘Althoughwe completed simulations, windtunnel and track testing, itwasn’t a fully integrated package– so we could run without it ifthere were any problems. Afterlearning the performance gainsfrom last year, we integratedaerodynamics into every singlepart right from the beginning.’A front and rear wing, shapedundertray and rear diffusermade up the aero package.Particular attention waspaid to the font wing as thiscontrols the entire aerodynamiccharacteristics of the car.According to the team, theoverall aero package increasedthe downforce by 30 per centwhile maintaining the samelevel of drag.While the high temperatureendurance caused many topteams issues, the Zurich carran strongly and quickly. ‘Oneof the reasons why we finishedendurance was because wereally pushed the manufacturingof our car to be complete byMay,’ Rohner says. ‘We had alot of time to evaluate and dealwith all the issues, but you alsoneed luck, and we were lucky tobe able to fix all the problemswe had to finish the race.’Fuel system: Lithium polymeraccumulatorsMax power: 4x35kW @ 16.000rpmMax torque: 4x28Nm @ 0rpmTransmission: 1.5 stage planetarygearboxDifferential: NoneFinal Drive: 1:11.8It is likely that some teamsin the future will copy, or atleast be heavily influenced by,the Zurich design, but Rohnerbelieves it is inevitable anywayas he feels that the designconcepts of top teams areconverging. ‘In the last threeto four years, we have seenmajor concept changes forelectric cars. For instance,our team started with DCmotors, no aero and 13-inchrims. Now with 10-inch rims,four wheel drive and anintegrated aerodynamic package.This is the winning concept,which is proved by othertop teams such as Delft andKarlsruhe.’ If that is the casethen expect to see a range ofsimilar cars in 2014.’"This is the winning concept, which is proved by other top teams"www.racecar-engineering.com • Formula Student supplement

KArlsrUHeHad it not been for itsdouble disqualificationfrom dynamic events, theelectric car from the KarlsruheInstitute of Technology wouldhave challenged for the overallwin. It certainly was a neatpiece of design, complete witha fully functional DRS wing.Its aerodynamic package wasan area that even the teamwere not entirely convincedabout, as team captain BenedictJux explains. ‘This car is oursecond with an aerodynamicpackage, and it’s hard to definehow effective it is,’ he says.‘It has some positive aspects,especially for an electric car. It’sdifficult to design because ofthe drag and the efficiency. Itimproves performance duringskidpad and autocross andespecially during the endurance,but if you have some problemsor need some more energy it canbe a burden. That’s why this yearwe designed DRS to decreasedrag and improve the efficiency.’Most of the evaluation workwas done using CFD, andthe team were keen to pointout that they used Star CCMsoftware to develop it, butthey also had not ignored somewell-proven techniques, andwool tufts were evident on theunderside of the wing when thecar arrived at Silverstone.Aerodynamics aside however,most of the work on the carwas put into its four wheeldrive powertrain. Unlike othercars driving all four corners, theKarlsruhe car does not use hubA lot of development was put into the four wheel drive powertrainmotors – instead it is fitted withfour inboard IPM motors.‘The special thing is thedrivetrain,’ says Jux. ‘It’s thefirst Formula Student car withthis type of drivetrain, no onetried this concept before. Thefour-wheel drive concept thatwe built in the last few yearswas a centre motor in the backand the wheel hub motors in thefront. This year two teams arehaving just wheel hub motors,which have much more unsprungmass. We decided that for theperformance of the car, it isbetter to put the motors in thecentre to reduce unsprung massand lower the centre of gravity.The challenge is probably thedynamic control, if you want touse the advantages of the fourwheel drive, but to get it to workit’s not that difficult. All fourwheels turn forward.’Reducing unsprung weightwas a key aim for the Karlsruheteam, and for that reason itmoved to smaller 10-inch wheelrims. ‘I think you can see onour car that one main goalwas to reduce the unsprungmasses. We did some testsat the beginning and bondedsome weights into the uprightswhich had a big influence – upto three-tenths difference perlap just because of the increaseunsprung mass. So for thewheels we have gone smaller,it has lower masses and lessrotational inertias. Most teamshave changed and the resultsfrom the event show that betterteams prefer 10 inches.’ Butthe smaller rims create theirown issues especially whenthey are made from carbon fibrewhich has a direct influence onbrake temperatures.‘We don’t have anyexperience about 10-inch rimsand our brakes,’ says Jux. ‘Ourbrake manager says that he’s notreally sure this will work out forthe whole of endurance so weCAUGHTA number of teams weredisqualified from theacceleration event atSilverstone, all of whomwere running electric cars.Karlsruhe, University ofSouthern Denmark and GroupT International UniversityCollege were all found to havebreached part EV2.2 of the2013 Formula SAE technicalregulations which statesthat: ‘The maximum powerdrawn from the battery mustnot exceed 85kW. This willbe checked by evaluatingthe Energy Meter data. Aviolation is defined as usingmore than 85kW for morethan 100ms continuouslyor using more than 85kW,after a moving average over500ms is applied.’ The penaltyfor this is disqualificationand all three were removedfrom the results. The biggestloser was Karlsruhe, whichhad won the event beforeits disqualification. It thenrepeated the violation in thesprint event and lost anotherstrong finish, taking it out ofoverall contention.PENALTY:DISQUALIFICATIONhave fitted brake ducts just forsafety reasons. It’s not a problemwe have had with 13, but weheard of some problems fromother teams last year, especiallywith CFRP rims. The rims arereally hard to develop.‘We had a 13-inch rim whichtook about two years to develop,but now we have this which wewill carry over on to future cars.They give weight reduction andmaybe a little bit of stiffness,but if you know how stiff yourrim is, you can manage it withother parts.’Just how strong the Karlsruhecar really was will probably neverbecome clear. It was certainly fast,but it was not legal, and whenrunning in fully legal specificationin the endurance it lacked pace.But the team were worriedif it would go the distance on asingle charge anyway.Formula Student supplement • www.racecar-engineering.com

FORMULA STUDENTWheely SmallIt often seems that FormulaStudent is driven by the needfor weight reduction. Overthe last few years, teams havebeen downsizing their enginesfrom four to two cylinders toreduce weight. More and moreteams have been trading theirsteel spaceframe chassis forfull carbon fibre monocoques toreduce weight. This year was nodifferent, as teams switched from13-inch to 10-inch wheels; toreduce weight. Indeed the overalltop four cars had 10-inch wheels.The theory behind the smallerwheel is not only the weightsaving, but the effectiveness ofthe weight saving in that area.As you may know, unsprungmass is defined as the totalweight of components that arenot supported by the suspension,which includes the wheels, tyresand uprights. The importance ofreducing this mass is becauseit is effectively uncontrolled, sothe lighter it is, the better thecontact between the tyre andthe road surface.After evaluating the dynamicequations, the translational androtational inertia effects of awheel can be expressed as anequivalent non-rotating mass,therefore it can be proved thatthe equivalent mass of a tyre istwice its static mass. In numbersthis means that if 0.5kg isshaved off each wheel, it wouldfeel 1kg lighter. Multiply this byfour and you can quickly see thehuge gains in weight reductionthat can be made. The knock-oneffect of reducing the rotatinginertia is that it improves theperformance drastically, as morepower is available to acceleratethe car, provided you are nottraction limited, in which casethe performance gains will stillbe made, just at higher speeds.Another benefit, althoughrelatively small in comparison, isthe effects under braking, as lessrotating inertia reduces the brakeload, and therefore heat.‘The main advantage of the10-inch is the weight savingand the improved accelerationcharacteristic due to the smaller10-inch wheels offer a substantial weight saving, but there are disadvantagescircumference of the wheel, andtherefore the lower final drive,’says Oliver Hickman, consultantmanager from Brunel Racing.‘Whether or not we downsize fornext year is a tough call becauseit would change how we runthe engine – we’re currentlysetup to compensate for the13-inch wheels, so we still getthe good acceleration. Therisk you get on the 10-inches,especially in damp conditions, isthe increase in wheelspin due tothe higher acceleration, as mostteams don’t have intermediatetyres. With the 13-inch you havea higher top speed. Althoughit’s not a massive difference, it’sdefinitely something we need totest and verify.’The smaller wheels requiresmaller components, sodownsizing not only has themultiple benefits of reducinginertia, but also the knock-oneffects of even more weightreduction. However, the 10-inchesdo create major disadvantages– yet the constant push forlightweight concepts make thesea small sacrifice, as the Stuttgartcombustion team described:‘Of course the packaging isvery difficult with the brakes,because the system is very smalland therefore gets hot easilyand quickly. Also, as the frontwing blocks air getting to thebrakes, we’ve added brake ductsfor cooling to utilise the flowfrom under the wing to travelinto the duct. There are somedisadvantages, but in the end youget more points with the 10-inchwheels than without.’Marcus Linder, team leader forChalmers, agrees. ‘It’s basicallydue to the weight saving.Although the data does showthe 10-inch wheels are worsein terms of peak lateral forceand tyre temperatures, the gainwe see in having less unsprungmass is worth the change.’ Afurther trend is the teams thatrun the 10-inches now makethem wider. ‘We can get a betterresponse and behaviour fromthe tyre when it is wider dueto the increased contact patch,’says Chalmers, ‘and the wideningdoesn’t affect the maximumlateral force too much.’Not only has the actualsize of the wheel changedfor weight reduction, but thedesign of the wheel too, withsome teams now developingcarbon fibre rims.David Turton, driver forTeam Bath and next year’sproject manager describes theirconcept: ‘This year was thefirst time we’ve run carbonfibre rims with an aluminiumcentre and we have saved anapproximate 600g per wheel. Aswell as this, there are stiffnessgains to be made as the cambercontrol is improved. Naturally,the design on CAD differs toreal-life when the car is fullyloaded, as it all deflects, whichis why stiffness is so vital,because it directly relatesto wheel control. We trieddeveloping the rims in 2011,but it’s only this year that theywere fully ready to implementon the car, which has just comefrom refining the design andpractising the in-house lay-uptechnique. The lightest carbonwheels on the grid are on TUGraz and Zurich, which have athree spoke carbon design andweigh in at just under 900gper wheel.’ As impressive asthis sounds, whether theselightweight wheels actuallyrun in the race is anotherquestion. However, carbon rimslook like the future, but onceagain the development costsand time required are powerfulfactors in determining just howmany teams we will see withthem next year."Downsizing for next year would change how we run the engine"www.racecar-engineering.com • Formula Student supplement

FORMULA STUDENTAdjusting AeroThe use of aerodynamicdevices is quicklybecoming a necessity inFormula Student. Last year, afterthe monster rear wing fittedto the Monash car, more wings,diffusers, undertrays and activeaero concepts were seen atSilverstone than ever before.‘It’s amazing the difference itmakes, despite the fact that werace at very low speed,’ explainsDave Turton, current driver andnext year’s project manager forBath University. ‘The averagecorner speed is 40-50km/h,so you would think that it’snot fast enough for aerobenefits. We have done backto-backcomparison with andwithout the wings and havefound lap time. However, this ismainly due to driver confidencewhen braking.’Bath have quite a smallaero package when comparedto other teams such as Munichand Monash, which is nearlythree times the chord length,yet still weighs a small 10kg.the Polish entry had the biggest wings, but perhaps not the most effectiveKarlsruhe’s car was also bewinged. note the wool tufts on the underside‘It then becomes a trade-offbetween downforce andmass,’ adds Turton. ‘If youhave advanced manufacturingprocesses that make the winglighter, you can run larger wings,yet still achieve the same centreof gravity and mass penalty. Ouraero is approximately 11-12kgincluding the mounts.’Monash are renowned asthe ‘pioneers’ of aero in theFormula Student world and it hasbeen their area of focus sincethe very beginning. Of course,access to their own full-scalewind tunnel has helped. Monashstate that their size wings arethe absolute minimum requiredto actually gain a benefit, inwhich case the circuits may needto become a little wider.AERO RESISTANCEOne team that has resistedthe challenges of aero untilthis year was Delft, whichbelieves that bigger is notalways better. ‘It’s been reallydifficult, but luckily we have alot of aerospace engineers in ourteam,’ said a representative. ‘Wealso have great facilities at ouruniversity so we complete windtunnel testing on scale and fullsizemodels, and so far the rearwing produces roughly the sameamount of downforce as theCFD predicts. With the massivewings you see on other cars, youjust add weight, which doesn’tmake sense for our lightweightconcept. This year with thesimulations we concluded thatan aero package would give usmore points in the competition,but maybe next year the ruleschange and aero may not beso important.’As mentioned in the racereport, the adjustable aerosystems were also makingappearances this year with boththe electric and combustioncars from the German Karlsruheteam running a very F1-styleDRS. However, many of theteams, such as Chalmers, don’tsee the benefit, as team leaderMarcus Linder suggests. ‘Wedid the analysis into whetherit would be worth having DRS,’he said. ‘But even though thereis a potentially small gain, itintroduces many problemsfrom the control side as it addscomplexity. However, we doadjust the wing depending onthe type of event, but once it’srunning the aero remains static.’Other teams have similarapproaches, such as Team Bath.‘For the acceleration event wetried to neutralise the rear wingby adjusting the trailing edge.It costs nothing to implementother than a few extra holes inyour sideplate, provided you’renot traction limited at highspeed. In terms of DRS, it is adifficult one. In Formula Studentyou have no chance to learnthe circuits, so to not only learnthem and learn the use of DRScould be driver overload. It’s alsoextremely risky because if theDRS stays open you’ll lose alot more time in that scenario,than the gain you would makewith it fully working.’A valid point, as Mercedesably demonstrated withMichael Schumacher’s DRS afew seasons back. However,this is not stopping teams fromdeveloping active aero, asTurton commented: ‘A teamin Oklahoma has an activefront and rear wing, which isimpressive, so all their multipleelements in the wing open andclose when the car drives intocorners. Another American teamhas an active rear wing thatsplits, so that they can activatehalf of the rear wing dependingon the steering angle. Therefore,when they turn into a cornerthey use the angle of attackon one side of the wing tocounteract body roll and increasethe vertical force on the insidetyres. Of course, in theory itis interesting, but in practiseif you’re counter steering,the system could be unstableunless you have an advancedcontrol system. Nonetheless,the corners at Silverstone arerelatively slow speed, so justhow much benefit do you reallyget from aero?’"It’s amazing the difference it makes, despite the low speeds”www.racecar-engineering.com • Formula Student supplement

FSAE – USABest in class – at lastStalwart competitors Stuttgart and Washington are celebrating their first FSAE winsFSAE MichigAnUniversitat Stuttgart havecompeted in Formula SAEMichigan since 2010 and finishedin third place every year. To some,a third place finish might beenough. However, to Stuttgartit meant there was always roomfor improvement.‘We have finally been ableto go the whole way to victory,’said team captain AlexanderJorger. ‘All the hard work thatwas put in, in addition to theEuropean competitions theyear before, enabled us tofinally win the sole event thatRennteam has participated inbut never won so far. But wedid it – meaning RennteamUni Stuttgart has achieved 13overall championships. And thatfeels awesome.’Formula SAE Michigan’scompetition returned to MichiganInternational Speedway (MIS)for its sixth year at the venue.There were 120 teams registeredfor the competition, however, only104 brought working vehicles.SAE International registeredteams representing collegesand universities from Austria,Brazil, Canada, Estonia, Germany,Mexico, Singapore, South Korea,the US and Venezuela.Technical inspection saw morethan 46 cars in scrutineering onWednesday in early inspectiondue to an extended schedule;setting a new limit of cars havingbeen reviewed on the first day.For those cars that passedall three steps of technicalinspection on Thursday, teamstook to the track on Fridaymorning, completing theiracceleration and skid pad runs.With temperatures of 65 degreesand overcast (usual for Michigan),Cornell University took first placein the acceleration disciplinewith the fastest time of 3.830seconds. Meanwhile in skidpad,Ecole De Technologie Superieuretopped the board with the fastesttime of 4.901 seconds.The University of Washington finished first overall at Formula Sae lincolnIn the afternoon, teamscompleted their runs for theSAE autocross. Finishing in firstplace with a clean run and besttime of 47.857 seconds wasOregon State University whichwas only 0.85 seconds fasterthan second place finisherMissouri University of Scienceand Technology. Clinching thirdplace was Universitat Stuttgartwith 48.827 seconds.Teams who completed theevent and placed were assigned aposition in the Ford Endurance runorder. Eighty-four cars took thegreen flag; 41 cars finished theevent with both drivers completingtheir 12 laps each. One teamfinished over the maximum timeallowed and only received pointsfor finishing all 24 laps.Placing first in this year’sendurance was University ofAkron, which had a clean runand total time of 1363.225seconds over 24 laps. Comingin second with an adjusted timeof 1370.749 due to hitting twocones was Tallinn University ofTechnology. Third was MichiganState University with an adjustedrun time of 1371.872, also dueto hitting two cones.Top 5 overall1st2nd3rd4th5thUniversitat StuttgartTallinn University ofTechnologyUniversity of AkronEcole De TechnologieSuperieureUniversite LavalFSAE LincoLn & FSAE ELEctricThe University of Washingtonwas awarded overall firstplace at the 2013 FormulaSAE Lincoln competition in theinternal combustion class. Alwaysa contender in Formula SAE, thiswas their first championshipvictory. Universidade Estadualde Campinas captured thefirst victory in the inaugural2013 FSAE electric classcompetition held in conjunctionwith the FSAE Lincoln event –this team previously competedin FSAE Brasil.The Formula SAE Lincolncompetition continued itssuccess for a second year at theLincoln Airpark. Registrationsfor FSAE Lincoln had a limitof 80 cars for the internalcombustion class while FSAEelectric class allowed for 20registrations. SAE Internationalregistered teams representingcollege and universities fromBrazil, Canada, Japan, Mexicoand the US.Taking first place in the costevent and receiving the SAECost Awards was the Universityof Illinois – Carbondale in theinternal combustion class,and Universidade Estadual deCampinas in the electric class.Six teams participated inthe design finals, with Car#4 University of Washingtondeclared the winner. Althoughthey did not make the designfinals, Car #201 UniversidadeEstadual de Campinas impressedthe judges and was awardedfirst place in the FSAE electricclass design award. The designjudges also recognised the FSAEelectric class second placed car ofUniversity of Kansas – Lawrenceand the University of Washingtonin third place.San Jose State Universitycompleted a successfulacceleration with the fastesttime of 4.123 seconds. Theskidpad event saw McGillUniversity taking first with thefastest time of 5.340 seconds.Meanwhile, the electric carof Universidade Estadual deCampinas won both accelerationwith a time of 4.452 secondsand skidpad in 5.444 seconds.In autocross, 54 carsstarted, topped by the time of51.569 seconds set by MissouriUniversity of Science andTechnology. Finishing closebehind in second was AuburnUniversity having their best timeof 52.100. Coming home thirdwas University of Illinois –Urbana Champaign.Fifty-four cars took thegreen start of endurance. Therewere 28 finishers, headed byUniversity of Washington,with a total adjusted time of1403.120 seconds over 19laps. Coming in second withan adjusted time of 1406.909seconds with a completelyclean run for both drivers wasCalifornia State PolytechnicUniversity – Pomona. And in thirdplace was Missouri University ofScience & Technology. First inthe electric class wasUniversidade Estadual deCampinas with 1824.652.Top 5 overall1st2nd3rd4th5thUniversity of WashingtonAuburn UniversityMissouri University ofScience & TechnologyUniversity of Kansas– LawrenceUniversity of Texas– ArlingtonFormula Student supplement • www.racecar-engineering.com

FORMULA STUDENT - VACAdVertisment feAtureOptimising performanceMaterials company VACUUMSCHMELZE GmbH & Co. KG (VAC) is playing animportant role in the Formula Student Electric championship by supplying threeteams with stator and rotor stacks made of cobalt-iron alloys VACOFLUX® andVACODUR® for their performance-optimised electric motors.To maximise powerdensity, electric motorsand generatorsrequire soft magneticmaterials with the highestsaturation induction, andpermanent magnetic systemscomprising high energy rare-earthpermanent magnets.These requirements arefulfilled by the materialsproduced by VACUUMSCHMELZEGmbH & Co. KG (VAC) in Hanau,Germany. The company alsohas the necessary technologiesin place for processing thesematerials into components, beforetheir installation into the finishedmotors and generators.The CoFe alloys VACOFLUXand VACODUR are examplesof these advanced softmagnetic materials. With asaturation magnetisation of2.3 T, significantly higher thanconventional electrical steel, theycan be used in electric motorsand generators to maximise theenergy density. Manufactureof the core stacks for electricpowertrains requires special careto preserve the outstandingproperties of the materials.A special productiontechnology, known as VACSTACK®has been developed to producecore stacks with the very bestproperties. As an effectivemethod of suppressing eddycurrent losses, ultra-thin tapes,no more than 50 or 100 µmthick, are used to achieveexceptionally high packingdensities, typically 98%, withoutstanding insulation betweenthe individual tape layers.Using VACSTACK technology,VAC is sponsoring the Swiss AMZracing team (ETH Zurich) withstacks made of VACOFLUX 48.The rotor stacks are assembledtogether with in-house producedAMZ racing team: race car “julier“Stator and rotor stacksmade ofVACOFLUX 48 andVACODYM 775 TPrare-earth based permanentmagnets VACODYM® 776 TP.The resulting components havebeen built into four motors forthe 2013 all-wheel drive race car“julier”. Each motor – developedand built by AMZ racing team –produces a maximum power of 37kW for a weight of only 4.6 kg.AMZ motor for race car “julier”An alternative way to producesuch lamination stacks is byusing interlocking technology. Inpartnership with AMK Kirchheim,VAC has supplied statorlaminations stamped from thenewly developed alloy VACODUR49 for their AMK DT5-series.These motors have been used bythe DUT racing team (TU Delft,Netherlands) and Greenteam(University of Stuttgart, Germany)in their four-wheel drive systems.Comparable to the AMZ motor,extremely high power densitiesof greater than 7 kW/kg have alsobeen achieved.This year, the three teamssponsored by VAC participatedin the most important events atSilverstone (UK), Hockenheim(Germany), Spielberg (Austria)and Varano (Italy). At Silverstoneand Spielberg, the electriccars started together with thecombustion engine cars in onesingle competition. In both cases,the AMZ racing team achievedfirst place (overall winner). AtSilverstone, it was the first timein the history of Formula Studentthat an electric powered car hadbeaten the best combustion car.At Hockenheim and Varano, therewere separate classificationsfor the two drivetrain systems.The competition for the electriccars in Hockenheim was wonby the DUT racing team whileGreenteam Stuttgart achievedthe first place in Italy.In addition to the resultsof the race competitions, twohighlights are demonstrated bythe outstanding performanceof the race cars sponsored byVAC: While the AMZ racing teamcaptured the first place in theworld ranking, the FormulaStudent Electric Dutch teamfrom Delft University improvedthe world record for accelerationof electric cars from 2.68 s to afantastic 2.15 s for 0 – 100 km/h.VAC congratulates all ofthe sponsored teams for theiramazing performance andlooks forward to some closeand exciting races in 2014. Thefuture of electric racing carshas just begun!Formula Student supplement • www.racecar-engineering.com

FORMULA STUDENT — MERCEDESRecruitment drive forMercedes AMG HPPFor one manufacturer, Formula Student has proved to be a rich source ofengineering talent. But the hunt for great young minds doesn't stop there…by ANDREW COTTONOne of the big attractionsin the Formula StudentUK paddock was theMercedes AMG PetronasFormula 1 showcar situated nextto the Racecar Engineering stand.The draw for the students wasnot just that here was a real-lifeF1 car in attendance, but alsothat the staff around the car werethere to encourage applications forgraduate placement schemes at itsMercedes AMG High PerformancePowertrains company, basedjust 30 minutes away inBrixworth, Northamptonshire.Mercedes AMG HPP is rapidlygaining a reputation amongstudents for its schemes,particularly at the CranfieldUniversity in the UK, and atFormula Student events. Theschemes offer a wide rangeof opportunities, working onvarious parts of the current andfuture Formula 1 power units.‘You don’t know where thegems are, and essentially weare after the best students thatwe can find,’ says Paul Crofts,head of materials engineeringat Mercedes AMG HPP. ‘While“Our sales pitch is:do you want towork in Formula 1?”www.racecar-engineering.com • Formuls Student supplement

the quality of the students atCranfield is very high, it wouldbe naive to think that it’s theonly place that they come from.It is a bit of a numbers game.The more people you talk to,the more people you will beexposed to and the more likelyit is that you will find the gemsof the engineers.’Students who approachthe stand are encouraged toapply for the scheme – withnew Formula 1 technologyon the way in 2014, freshthinking is critical for success.Although the next placementsstart in September 2015,there will still be a significantamount of developmentfocused on performance andefficiency ahead of the 2016season and beyond.‘I think at the moment, weare not that sure what thestudents will be working onbecause we haven’t had a newengine on track yet,’ says Crofts.‘At the moment it is like doingthe 400m race at the Olympics,but everyone is in a differentstadium. We have no idea howfar ahead or behind we are,so we are not sure what thestudents will be working on.Clearly, though, anything aroundboosting systems, electricalhybrid systems, harvestingsystems, deploying energymore efficiently – they aregoing to be the areas that weare continuing to work on,as well as more traditionalcamshafts, exhaust pipes andso on. It is across the range.Formula 1 is about detail,and every detail, so we will beleaving no stone unturned.’Recruitment starts inSeptember 2013 and runsthrough to Christmas fora placement that starts inSeptember 2014. In that time,Mercedes AMG HPP is lookingto recruit the very bestengineering students fromall walks of the discipline.‘We have a two-yearformalised training programme“Half of our graduate engineershave had an involvement withFormula Student at some point,so it is important to us”Standout students may work on current and future Formula 1 power unitsWRI2where each graduate rotatesthrough our various engineeringdepartments building upexperience depending on whattheir base degree is,’ saysCrofts. ‘We take on mechanicalengineers, manufacturingengineers, electronic engineers,software engineers and we tailorit to that background, but we givethem variety, so they get a biggeroverview of our business.‘Once we highlight that tothem they start to get interested.Then we highlight the factthat we are in the UK. MercedesAMG HPP may not have a highprofile in the outside world, butwe are not a stealth company anymore. Still, we have to remindthem that we are local, and thatwe’re only 30 minutes fromSilverstone. The key thing isthat candidates have to applynearly a year in advance. Ourapplication window is Septemberto Christmas this year to start thejob in September 2014.’‘We recruit about 10 graduateengineers each year, and take onabout 25-30 placement students,who are just as likely to come fromthis event because it is not onlyfinal year students, it is years 1,2 or 3. Generally speaking, 50 percent of our graduate engineershave had involvement withFormula Student at some point, soit is important to us. Our graduateprogramme has only been goingfor five years, but our retentionWith a new breed of Formula 1 engines on the way, there is huge demand for fresh thinking in engineeringFormula Student supplement • www.racecar-engineering.com

FORMULA STUDENT — MERCEDES“our ex-graduates are working on the 2014 F1 power unit at the moment”rate is over 85 per cent, and afterthe two-year course, they usuallyearn a permanent position inone of our departments. Wedo encourage our engineersonce they have a permanentposition to work in one place fortwo or three years, and then lookto move to another place aroundthe company anyway, so they canget that variety.’That variety may not be inthe diversity of projects –Mercedes HPP is 98 per centconcentrated on the Formula1 programme – but there areoccasionally opportunities togo slightly further afield withinthe Daimler Group. The companyprovided the battery pack forthe Mercedes SLS Electric Drive,which was developed from theFormula 1 system and scaled upto meet requirements. Just withinthe scope of Formula 1, morethan 400 people are employedat HPP, and over 100 of them areengineers with a hands-on role indeveloping the Formula 1 engines.‘Our ex-graduates areworking on our 2014 F1 powerunit at the moment,’ says Crofts.‘It’s less than six months beforewe have to be on track for thepre-season track test. We willhave a much bigger ERS or hybriddrive system, turbochargedtechnology, a downsized enginethat has to be more fuel efficient– they are all areas that we haveto work on, and everyone’s ideasare valid. We are maximisingour engineering team to workon that and get as muchbrainpower on it as possible.Whether you have worked in themercedes take on around 10 graduate engineers each year, in additionto an intake of placement students at various points in their studiesindustry for 20 years, or a year,your ideas are probably just asvalid at this point.‘I think there will besignificant evolution in 2015.Unlike the current V8 rules, wehaven’t been able to change itfor seven years. The way thatthe sporting regulations havebeen drafted, year by year from2014 to 2020, you will be ableto change less and less, butfor 2015-2016 it is still veryopen, so I suspect there will besignificant changes, not onlybecause of reliability issues, butalso to find more performance.‘At the end of February2014, the power unit will behomologated and effectivelythat is then fixed for the year.There is some calibration workto be done, and that work willcontinue. We had placementstudents working on the V8, sowhat they are working on is ontrack in two weeks time. In termsof the hardware, it will be fixed.However, those that are workingon that will turn towards the2015 power unit.’The application process forthe graduate training schemestarts in September. Studentsare encouraged to apply atwww.mercedes-amg-hpp.comPlacement in action – Graham’s storyPresent at Silverstone’sFormula Student eventwas one of the graduateson a two-year scheme atHPP who was approachinghis first anniversary at thecompany. Already, Graham hasworked in three areas of thecompany, worked on a thermalmanagement programmeon the current F1 engine, andgraduates move to new rolesin different departments everythree months.‘I first heard about [HPP]at a presentation that oneof their ex-graduates did atthe university, which got meinterested,’ says Graham, whosesurname cannot be printedfor reasons of confidentiality.‘I thought that it was quiteexciting to do as a job. At thetime I was involved in FormulaStudent, which gave me a setof skills that are transferableinto the job. It gave me a lotof experience of workingunder pressure, meeting shortdeadlines, that sort of thing.‘For the first two years youdo a mechanical engineering job,and then you specialise afterthat, and I chose automotive.I had done a placement for 12months, which gave me someexperience. It was about thecompany, it sold itself. I startedon the graduate placementscheme in September, andsince then I have been in threedepartments – the design officefor mechanical engineering,performance for the existingengine, and manufacturingengineering. As part of theprocess, you visit all sortsof departments around thebusiness, and the idea is that youare exposed to everything that isgoing on. By the time you havefinished your two years, youhave the mindset and are awareof the processes and you can bebetter at your job at the end of it.Of the ones I have experiencedso far, the performance role wasthe one that I enjoyed the most,and I have subsequently appliedfor a job from that.‘In performance you get awhole project that is yours, andI was given a project looking atheat rejection for the Formula 1cars, and you could maximiseour performance and see whatcooling requirements we wouldneed. That was my baby and italso used some simulation skillsthat I had used in university, so Ireally enjoyed that. I found it tobe really rewarding.‘It is quite normal for thiscompany to be given thatresponsibility. The head countis lower, you have a big projectto do, and everyone has theirown significant part of thatproject, and in a large automotivecompany you might be working onsomething much smaller becausethere are more people around.’Crofts adds: ‘We like to giveour graduates responsibility. Ifyou are going to give them a job,give them a real job to do. Makethem feel that they are reallycontributing, because they are.There are over 400 employees,split between six engineeringdepartments, and seven or eightdepartments on the operationalpart of the business. Inengineering, we have over 100engineers, and a lot of peoplewho need to make that happen.'www.racecar-engineering.com • Formula Student supplement

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TECH DISCUSSIONSave Formula StudentTeams are turning up with great tech, fine paint jobs and a well-drilled crew.But with one key rule routinely broken, is anybody actually learning anything?Iparticipated in Formula Studentcompetitions between 2006and 2012, and was designleader for a student teamthat designed and built their owncomplete racing engine from scratch(and CNC machined everything thatwas possible by ourselves, see RaceEngine Technology magazine #54).In my time I also TIG-welded entirespaceframes, wishbones, uprightsand CNC programmed and machinedour aluminium suspension uprights.My own experience was that fiveyears of Formula Student wereprobably the best years of my life,and will probably never be equalledin terms of capacity for innovation,real teamwork, real camaraderie,and a pace of learning of suchfrantic magnitude that would putmost of F1 to shame.However, the face of FormulaStudent has changed a great dealsince 2006, and I saw the transitionoccurring with my own eyes. Iwould also state that this transitionis not for the better. FormulaStudent has (for many teams,universities and apparently judges),increasingly become a showcasefor turning up with the mosttechnology, the best paint job,and the most professionallyturned out and drilled team. All ofwhich on the face of it seem verylaudable qualities indeed. In fact,it is clear that unfortunately notone of these qualities necessarilycontributes to the personal,intellectual, moral or technicaldevelopment of the studentsthemselves (of course there areexceptions to this in a small numberof exceptional teams). It is a factthat the vast majority of FS cars atevery event are in direct and clearcontravention of Rule A6.1 (page12, FSAE regulations 2013):professional engineers, automotiveengineers, racers, machinists orrelated professionals.’If this rule were enforced at thenext competition, the number ofeligible runners at an event like FSGmight be counted on one hand. Thereis an argument that some teamscannot build their own cars becauseof safety fears at their establishment,or that they don’t have anyequipment. But I think this is a copout,preventing teams really learningwhat running a racing business is allabout, which is to need something,and then getting together to make aplan in order to achieve it.Not to complain that it’s ‘difficult’,and so allow a sympathy loopholethough which anyone can now leapwith anything up to an entire chassisbeing constructed almost 100 percent by renowned motorsport firms,stickers being applied and this beingdeclared a ‘Formula Student car’.When, in fact, it is nothing of the sort.For a really dedicated andintelligent group of students,building a vehicle to the letter ofthe rules in section A6.1, wouldbe NO barrier to innovation nor tothe technical level achievable. Forexample, UWA constructed their ownmoulds for their CFRP tub, and curedit by constructing a ‘hot box’, aroundthe finished mould which washeated by hot air guns applied towell located vents. Not an autoclavein sight. Allowing teams to blatantlycontravene rule A6.1 also allowsuniversities to carry on denyingIf rule A6.1 was enforced, studentsreally would build it all themselvesstudents access to manufacturingfacilities, because ‘everyone elseis doing it’ – as in everyone elseis farming out machining, curing,testing, welding, moulding etc toexternal companies.If this rule were properlyenforced, it would empowerstudents to really have their ownracing team, really build it allthemselves and to really gain thesort of self-confidence that canonly ever come from having doneit all yourself. It would also forceuniversities to get behind learning,and to not merely listen to theirlitigation department’s risk reports.If there are teams who claim thatthey ‘cannot’ build their own cars,because it’s ‘difficult’, or becausethey’re not imaginative enough tobeg/borrow/buy/rent appropriatefacilities and equipment – I wouldquestion their eligibility to considerthemselves worthy of competingto go home with their heads heldhigh as young racing enthusiasticengineers of the future.The regulatory bodiesresponsible for running FormulaStudent are responsible for farmore than just helping to setupand run the events, by their actionsthey shape the way students learnand function at their universities.Rule A6.1 should be eitherenforced to the letter, or it shouldbe deleted with immediate effectfrom the rules and regulations.If it is to be deleted, all concernedmust be comfortable with thefact that the competition would– in principle, practise and letterof law – cease to be a primarilylearning exercise.Calum DouglasA6.1 – Student Developed Vehicle‘Vehicles entered into Formula SAEcompetitions must be conceived,designed, fabricated and maintainedby the student team memberswithout direct involvement fromFormula Student should beteaching people key design andengineering skills – but manyschools are denying students thisopportunityFormula Student supplement • www.racecar-engineering.com

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