Septembers Technical updates

I’ll compress this months work into one post for simplicity. For updates on F1 technology have a look at the following outlets: Automoto365.com, Motorsport Magazine and Race Engine Technology magazine.

Automoto365.com – Singapore Tech Desk
All the technical devleopments from singapores night race.
– McLarens front wing and nose cone (thanks to bosyber comments on this blog)
– Red Bulls updates
– Mercedes Bargeboards
– Williams Frotn wing
– plus more from Renault and Toro Rosso

http://f1.automoto365.com/news/controller.php?lang=en&theme=default&month=10&seasonid=21&nextMode=ExclusiveNewsForm&news_id=42469

Motorsport Magazine – F1’s Aero Tricks

I’ve illustrated this article on this years must have developments: F-ducts, Exhaust Blown Diffusers and deflecting splitters.

http://www.motorsportmagazine.co.uk/2010/09/30/latest-issue-%E2%80%93-november-2010/

Race Engine Technology


What lies inside a contemporary Formula One engine? Toyota have given Race Engine Technology full access to their current RXV-08 F1 engine. This issue contains the most detailed technical article ever published on a current F1 engine. A 16 page article covering all aspects of the Toyota Formula One engine in a level of detail you will have never experienced before. RET have been given unprecedented access to the engine with the full co-operation of the entire technical team.

http://www.highpowermedia.com/mall/productpage.cfm/RET/2050/352560

F1 Tech in ‘Race Engine Technology’ Magazine

This months ‘Race Engine Technology’ magazine has some interesting stuff for F1 Tech followers. There’s an interview with Mario Ilien, who explains the work he did with Mercedes-Ilmor including; Hydraulic KERS, a rotary valved V10 (+20k RPM & 78Kg) and of course Berylium for Pistons & Liners.
In the Report from the F1 British GP, the Editor interviews Adrian Newey, Also Costa, Sam Michael and James Allison. Covering several topics; the effect of engine power\drivability\consumption, as well as gearbox design influence on aero, with Newey commenting the Pull Rod was a carry over from 09 & not a requisite for his RB6 design. While Ferrari confirmed their engine\gearbox assembly is inclined at over 3-degrees, the first time I’ve seen a reliable quote confirming this fact. It was added that Sauber take this set up for their C29, while Toro Rosso have their own gearbox so have a horizontal drivetrain.
Lastly is a small section on how Sauber pioneered current gearbox design with a longitudinal gearbox, with the gears ahead of the final drive and contained within an aluminum case. It surprised me that Harvey Postlethwaite was involved in this, is there anything that man didn’t do in F1?

Not generally available in the shops and not cheap, but well worth a one-off purchase or subscription.

http://www.highpowermedia.com/mall/productpage.cfm/RET/2049/348121

RACE ENGINE TECHNOLOGY 048 AUGUST 2010

Intro: THE EDITOR
Racing powertrain technology is on the verge of a revolution; Ian Bamsey says this issue gives some hints as to what to look for

Upfront: MARIO ILLIEN ON FUTURE TECHNOLOGY
Ian Bamsey talks to Mario Illien about his pioneering work in Formula One during the V10 era and the future of race technology

Grid: IN THE NEWS
Peugeot’s con rod dramas; HPD’s new LM P2 V6 turbo; Le Mans’ Hybrid u-turn; John Medlen’s new role at DSR and much more

Dossier: PORSCHE 911 GT3 R HYBRID POWERTRAIN TECHNOLOGY
Ian Bamsey investigates how flywheel-based storage of recovered kinetic energy has been pioneered in professional racing

Race Report: BRITISH GRAND PRIX
Despite the ongoing engine freeze, Ian Bamsey discovers some significant powertrain developments at the British Grand Prix

Focus: CAMSHAFTS
Wayne Ward discusses the options available for the design, materials and manufacturing methods for race camshafts

Insight: RACE ENGINE INSTALLATION
Le Mans-winning designer Peter Elleray on the relationship between engine and chassis design, highlighting where their needs conflict

Focus: THE GEARBOX
John Coxon explains key points in designing and building a motorsports transmission – from the gear teeth to choice of differential

Race Report: LE MANS PROTOTYPES
Ian Bamsey gives a rundown of the various engine strategies deployed by this year’s Le Mans Prototype competitors

PS: SAUBER C12 TRANSMISSION
How in 1993 Sauber’s first Formula One car prompted a major shift in transmission technology

To view a sample article from this issue please click here

Price £12.50

Splitters Explained

Although low down in a dark area of the car and hidden behind bargeboards, the front splitter has been a critical part of the F1 car for many years. Known by many other terms, such as the shadow or legality plate, T-tray or bib, I’ll refer to this part as the splitter.

Since 1983 F1 cars have needed a flat floor in-between the front and rear wheels, then this floor needed to be stepped since 1995. In the late eighties when designers were slimming and raising the nose of the cars, there was a need to create a floor section under the front of the monocoque to meet the flat bottom rules. The most obvious first splitter was the Tyrrell 019 with its fully raised nose, since then the splitter has been more and more exposed as teams seek to raise and narrow the chassis cross section for aerodynamic benefit.

A splitters regulatory role has been to form the flat bottom of the car and from an attachment for the ‘plank’ running along the length of the flat floor. Thus the splitter must form the flat floor at reference plane level (the datum level where all bodywork measurements are, although the plank sits below this level). The splitter must also shadow the plan profile of the monocoque, such that the monocoque cannot be viewed from beneath the splitter.

However the need to have this bodywork forming the floor has been exploited and the splitter now forms aerodynamic and chassis functions of its own. As the term suggests the splitter separates the airflow passing under the raised nose between that which passes above and below the floor, equally its boats ‘bow’ shape above where it meets the monocoque also splits the airflow passing over the floor between left to right. Air then spills off the upper surface of the splitter and some of this will make its way under the floor and towards the splitter, thus the teams make use of this powerful flow to alter the pressure distribution across the underfloor to further improve airflow through the diffuser. allied to the fences, vortex generators and previously bargeboards, the splitter forms a critical role in the onset flow for the diffuser.

Brawns 2009 ballasted splitter

Being mounted low and far forward, the splitter also forms the location for ballast. Depending on the prevailing tyre and aerodynamic issues, teams can run as much as 50% of the cars weight on the front axle. with a rear engine car, the only way to do this is the ballast the front of the car and the splitter has been known to be made entirely from metal in order to maximise front end weight bias. Under the current aero and tyres rules, weight is somewhat more rearwards and the splitter is less heavily loaded with ballast

Deflection
In 2001 when the technical regulations demanded raised front wings (excluding the middle 50cm section) teams found the raised front ride height, cost downforce. Attempts were made to artificially lower the front wing when on track, both by flexing and by lowering front ride height. such is the geometry of the car, that the car cannot achieve enough rake to lower the front ride height without either excessive rear ride height or the splitter hitting the ground. A high rear ride height will cost rear downforce and stability, so the splitter needed to be moved out of the way. Teams found that deflecting the splitter upwards as it hits the track surface under braking allowed for lower ride heights. making the splitter far less stiff than it needs to be allowed the splitter to ride up without undue wear to the plank and skids which are measured in scrutineering for wear. Excessive wear to the skid block will bring penalties for the teams and drivers.

Hinged splitters allow lower front ride heights

However the FIA became wise to this practice and along with other deflection tests carried out on the he scrutineering rig, a test with push a hydraulic ram up from under the splitter was introduced. The car is bolted to the rig and the ram applies 200Kg of pressure to the front edge of the splitter, only 5mm of movement is allowed. this forced teams into running stiffer splitters and hence higher ride heights.

A hydraulic ram rises from the test rig to measure deflection to the floor

In order to regain the lower ride heights teams once again worked around the rules, by making the floors deflect at loads higher than the 200kg test. by hinging the splitter at its rear mounting and then making the front mounting a preloaded to 200kg. thus the floor will be be able to meet 200kg FIA test with little movement, but at loads over 200kg the front mounting will start to deflect and allow upwards movement for lower ride heights and more downforce. In Ferraris case this was a mounting with a small coil spring to provide the resistance to the 200kg load. McLaren had a pre-buckled stay, acting like a leaf spring between the floor and splitter. The justification for these very visible mechanical mounting was to avoid damage to the now very heavily ballasted splitter, when running over kerbs and bumps etc.

Ferraris 2006 preloaded sprung splitter support

One of the issues to fall out from the technical interchange between McLaren Mike Coughlan and Ferrari Nigel Stepney was Ferraris use of the splitter mounting. Knowing how Ferrari used the mounting allowed McLaren to ask the FIA technical delegate Charlie whiting for permission to use such as a system. this approach is a subtle workaround to a formal protest of another teams design, but ends up with the same result, either acceptance or a clarification banning the design. This issue arose at the start of 2007 and by the Spanish GP the teams were asked to remove deflecting splitter mounts, necessitating a redesign for most if not all teams. some people within the sport suggest Ferrari performance advantage from the previous few years was eroded by this rule change. since then teams run far stiffer splitter mountings and although several teams have been asked to revise their mountings since then by Charlie whiting, it is felt that there is little that can be done to deflect the splitter for performance benefit.

As you can see, FW Ride height is restricted by the splitter, unless the splitter deflects upwards

One of the explanations for the low wing ride height on the RB6 are suggested to be the splitter is allowing lower ride height by deflecting. Certainly trackside images suggest the Red Bull and the Ferrari are running significantly more rake in the set up at speed (i.e. nose down). Other teams suggest that this level of rake and low front wing ride height cannot be achieved with normal rear ride heights. But do not suggest how the car may be able to run that low. But the inference is that the splitter is in someway deflecting to allow this. I’ve not seen the detail of Red Bulls splitter mounting, but I doubt they are able to deflect the splitter without any obvious compliance in its mounting or undue wear to the skid blocks.

On a side note, it was Coughlans assertion that the Ferrari splitter of 2007 was also being sprung to create a mass damper effect, with mass dampers being banned the previous year.

Quote from Racecar-engineering.com “One of the defences used by McLaren was that Stepney, the former Ferrari employee, was ‘whistle blowing’ – something the court struggled to accept covered the whole affair, but it did certainly have an effect at the Australian Grand Prix. Ferrari won the race, but the FIA later outlawed the car’s floor. McLaren contended that the Ferrari that won was illegal, and a letter from Stepney to the FIA sent after the hearing revealed that it may well have been, as it was in effect a mass damper. Such devices were banned last season as they were controversially deemed to be a moveable aerodynamic device.
Stepney reveals in detail the exact workings of the floor that was used at the race: ‘The front floor is attached to the chassis via a mechanical hinge system at its most rearward point. The most forward support is a body with one compression spring and one tension spring inside which can be adjusted according to the amount of mass that is fitted to the front floor. There is also a skirt that seals the floor to the chassis, which is made out of rubber and Kevlar to help flexibility and reduce friction in the system.
‘If the system had been allowed it could have meant a huge cost of development for other teams in such areas as chassis and under trays etc to make way for the provision for storing the system and the variable quantity of mass. The possible long-term consequences of such a system would be quite substantial because the system is in a crude state of development.’
The system detailed by Stepney allowed the F2007 to ride kerbs harder due to the 14-15mm deflection at the leading edge of the floor, which means the Ferraris could straight line chicanes more than other chassis. Front plank wear would also be reduced, allowing the car to run lower at the front, giving an aerodynamic gain.
Stepney also explains the dynamic behaviour of the car, and the advantages the flexing floor gives: ‘From around 160-180km/h (100-112mph) the car is about 7-8mm lower at the leading edge of the floor, which multiplies up to nearly 19-20mm lower front wing height. The benefits in terms of ground effects and efficiency would be gained all around, with components like turning vanes and front wings at a reduced height relative to the ground.’ “

 

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Germany Tech Review now on Automoto365.com

My Technical review from Hockenheim is now on Automoto365.com.  With the update on McLarens Blown diffuser, Mercedes and Williams exciting ‘open-fronted’ exhaust blown diffusers, as well as updates from Virgin and Toro Rosso.

http://bit.ly/aviB74

or

http://f1.automoto365.com/news/controller.php?lang=en&theme=default&month=7&seasonid=21&nextMode=ExclusiveNewsForm&news_id=41729

Aero elasticity – Red Bulls front wing

 

A very public exposure of the front wing flexing on the Red Bull was made during the German GP, the analysis by journalist Stephane Samson and photographer Darren Heath, showed the tips of the Red Bull front wing running far closer to the ground than their rivals. While some of these pictures can be explained partly by different ride heights, roll positions or attitude changes, some pictures show the Red Bull front wing in a drooped (anhedral) attitude. This has been backed up by on board footage, where by the roll hoop camera is fixed rigidly to the car and any movement of other sprung parts of the car should remain immobile in relation to the camera. Yet still the RB6 has routinely exhibited excessive movement through out the car speed range.

Aero Elasticity
Since the nineties F1 teams have been exploiting a phenomenon called “aero elasticity”, this is where the bodywork of the car, mainly the wings, flex to alter their aerodynamic characteristics. At first this was largely created by the entire rear wing assembly bending it backwards, then more specific parts of the rear wing and as exposed this season, the front wing of the Red Bull has been visibly flexing.

This flexibility can be for three different benefits, either reduced drag, improved balance or greater downforce. With a rear wing limiting top speed, most attention has been paid to reducing its drag. As mentioned this was first tackled by the top rear wing and endplates being angled backwards by the beam wing twisting. A few pre-season failures leading to big accidents saw the FIA introduce the first bodywork flexibility rules. In order to enforce the rules, the FIA designed the first deflection test, a rig pulls the wing backwards by the endplates and the deflection was measured. While this test stopped this practice, it also set a standard to which the cars had to meet in order to be deemed legal. Thus if the car passed the scrutineers deflection test, it was approved to race. However if the car could flex its wings and still meet the test, then they had an advantage that couldn’t be immediately penalised.
Soon teams sought to reduce the angle of attack of the rear wing via flexing the flap or main plane. Then as the FIA introduced additional deflection tests to circumvent these workarounds, the teams flexed the wings to reduce the slot gap and stall the rear wing (Much like a passive F-duct), again deflection tests and latterly the slot gap separator effectively stopped this practice.

Front wing flex

 
Exploiting aero-elasticity with the front wing has not been to reduce drag for greater straight-line speed, as the front wing produces very little drag. At the end of the nineties teams were using front wings that drooped into an anhedral shape (i.e the tips drooping downwards creating an inverted “V” shape). This placed the wing and its endplates closer to the ground, both of which gained more downforce. Firstly the wing was closer to the ground which increased the ground effect. Up to a point the lower a wing is to the ground the more downforce it generates. Then the endplates role in sealing the high pressure above the wing from the low pressure below it, is improved if the endplate can run closer to the ground. Effectively make it act like an Eighties wing-cars skirt. To prevent this the FIA produced another deflection test; a 50kg (500n) load is applied to the wings endplate, should not produce more than 10mm of movement. Again this had largely stopped the practice of excessive deflection for front wings.

However there were still benefits to be had from flexing the front wing flap that was not affected by this test. Instead the wing has been flexed to main a stable centre of pressures position, flexing the flap downward at speed to reduce the wings angle of attack reduced downforce and moves the centre of pressure backwards, reducing the cars tendency to be oversteery at high speed. There is now a deflection tests to prevent this practice.

Red Bulls RB6 front wing

At some races last year and evident through out this year is the front wing of the Red Bull RB6 flexing at speed. Visible from the on board camera above the drivers head, the front wing tips can be seen to slowly run closer to the ground as the car accelerates. As this is a low frequency movement, the effect can be seen in reverse as the cars brakes from high speed. The wings endplates springing up as the car rapidly loses speed and the aero load applied to the wing diminishes. This was clearly visible from the early season races and as early as the Chinese GP I emailed the FIA about this practice and whether it was deemed legal. They reiterated the standard 500n – 10mm deflection test and suggested the car was legal, not directly countering the point that the wing is seen flexing. While most teams wings will flex at high speed, whereby some movement is often seen as the car brakes from high speed. The amount of movement and the low speed at which it starts to occur are startling with the Red Bull wing. The point made by the FIA to me back in April and again after the German GP in late July was that the car met the deflection test, thus was legal to race.

This flex was seen back in China 2010, not simply Germany

Front wing Load cases
An F1 car makes its own weight in downforce at just 70mph, that’s ~600kg of load on the car, half of this load is from the wings and half from the diffuser, thus the wings create some 300Kg of load at this speed. With the cars centre of pressure being some where near 45% forward biased, this means the front wing is creating something like 140Kg of load, split between the left and right wing each wing is producing 70Kg of load at just 70Mph. this is the speed of the slowest turn at the Hungaroring this weekend and only slightly faster than the hairpin at Monaco! Thus the FIA limit of 50kg is vastly under specified for the actual load an F1 car sees at even the slowest circuits. Its not surprising a team can created a wing to beat the 50Kg-10mm deflection test and yet achieve far greater deflections, suggested to be as much as 25mm, at much faster corners.

How’s this done – is it legal?
An F1 front wing is a complex moulding of carbon fibre bonded to metal sections. Although the flaps and endplate are detachable, from a structural point of view a front wing is a single piece. Mounted at its centre section by pylons affixed under the nose cone, itself stoutly fastened to the front of the chassis. In the eyes of the rules and with the exception of the driver adjustable front flap, the front wing should meet the regulation 3.16 regarding aerodynamic influence:

-must be rigidly secured to the entirely sprung part of the car (rigidly secured means not having any degree of freedom);

– must remain immobile in relation to the sprung part of the car.

Therefore the entire assembly can not be allowed to move in relation to the rest of the car. However no car can be 100% rigid and F1 cars are subjected to huge aerodynamic loads, hence the reason for the FIA to set the deflection test. If the wing can meet the test and still deflect above the test load, then the FIA deem it legal and the car can race. This could be achieved by accident or by design. Its possible that the carbon fibre lay up creating the wing will continue to deflect in a linear way all the way from zero load to 50kg and then for loads of 50kg upwards. It’s reasonable to assume most teams wing respond this way. However it’s possible to alter the layup of the carbon fibre or add some from of mechanical system (i.e. hinges or springs) to allow a non-linear repsonse to create the 10mm of movement at a 50Kg load, then create greater deflections above 50Kg. Thus the engineers could create wing that meets the deflection test, but would then deflect down to a desired ride height at a specified maximum speed.

While this is against the “spirit of the rules” which prohibit flexible bodywork they meet the test as defined by the FIA for flexible bodywork, thus the Red Bull and the Ferrari front wings are free to race in the eyes of the FIA.

I have again emailed the FIA to ask about additional deflection tests and have yet to receive a response.

Red Bull Map-Q: The secret to the teams Q3 pace

As explained in my post on ‘EBD’s’ – Exhaust blown diffusers (https://scarbsf1.wordpress.com/2010/06/25/exhaust-driven-diffusers/), teams blowing their diffusers rely on the throttle being open to keep airflow passing to the diffuser. Without this airflow, the diffuser loses downforce and the driver suffers a loss of grip or balance just as he enters the corner. 

While careful design and how the exhaust is placed in relation to the diffuser, can alleviate some of the problems, any benefit from blowing the aerodynamics will be reduced when the throttle’s closed and no exhaust gasses are flowing. 

It’s been reported that Red Bull are following a practice that was used on turbo cars (i.e. the old F1 turbos and WRC cars) to keep the turbo spooled up. By means of retarding the ignition when the driver is on the overrun as he slows for a corner. If Red Bull can keep the flow out of the exhaust pipe relatively constant, even when the throttle is closed going into a turn, then the diffuser will see a more consistent air flow and maintain downforce. Relieving it of the on\off throttle sensitivity so often a criticism of EBD systems. In effect an antilag system is trying to do the same as the Red Bull EBD mapping, maintaining a constant exhaust gas pressure, on or off the throttle. 

Ignition normally occurs within the cylinder, driving the engine

 

When an engine is running normally, accelerating with the throttle open, the ignition of the fuel and air takes place inside the cylinder above the piston. The expansion of the gasses drives the piston and turns the engine. 

After ignition, the exhaust valve opens and the cooler gasses rush down the exhaust pipe

 

During this process the gasses then escape into the exhaust pipe as the exhaust valves opens. As the burning has already occurred the gasses are some what cooler, the then temperature of the actual ignition. This means the exhaust gasses flow down the exhaust pipe with some speed and energy. 

On a closed throttle, little air or fuel are burnt reducing the exhaust gas flow

 

When a driver lifts off the throttle, the engine does induct much air, nor burn much fuel, as a result the engine slows and the exhaust flow also slows down. It is this problem that affects the diffuser, as it sees less exhaust flowing through it. 

With retarded ignition, the mixture burns in the exhaust creating a flow of gasses through the exhaust

 

What Red Bull do is retard the ignition and maintain some throttle and fuel to allow combustion to continue to take place. However the ignition of the air and fuel mixture now takes place later in the engines revolution, when the exhaust valve has already opened. Rather than driving the piston down, the explosion of the mixture goes into the exhaust, still expanding as it does so. This creates a rush of gas through the exhaust mimicking the effect of running with the throttle open. Thus the diffuser still sees a flow of gas and maintains downforce despite the engine slowing down. 

Retarding the ignition overheats the exhaust components (red)

 

Of course this gain doesn’t come for free, the heat of combustion now takes place in the exhaust port, so that the exhaust valve, cylinder head and exhaust pipe all suffer excessive heat. This will affect them, as they cannot withstand this sort of thermal load for long periods. Equally the process burns additional fuel, in the race this is a negative thing as fuel is limited and no refuelling is allowed.
This ignition retard mapping would be controlled via the SECU via the driver selecting a steering wheel control, using quite normal tuning parameters and not some clever workaround. Of course this is all quite legal. 

If the overheating issues can be contained, this would be a relatively simple mapping to introduce for another EBD team. As mentioned Renault Sport, Red Bulls engine supplier would have to know about this. Copying the concept, but not the actual SECU code would be quite easy.

Valencia: Technical review now Automoto365.com

 

My Technical review is now online at Automoto365.com.  With the latest updates across the grid.

http://bit.ly/aGG7yC
or
http://f1.automoto365.com/news/controller.php?lang=en&theme=default&team_id=0&month=07&seasonid=21&nextMode=ExclusiveNewsForm&news_id=41314