Happy New Year – RedBull RB6 Illustration (Wallpaper)

Posted on December 31, 2010 by scarbsf1

I’ve been drawing this big detail – big scale illustration of the RB6 as a prelude to a prediction of the 2011 car designs. So I’d thought I’d post the 2010 RB6 version up as a wallpaper in mono at 1280 resolution. I’ll do larger sizes on request with or without logos (mail me).

Have a great New Year and thanks for supporting me in my first year Blogging and Tweeting. Next year will be my tenth covering the technicalities of the sport, so I’ve got some new ideas up my sleeve.

Scarbs…

and without Logos…..

F1 2011 Technical Regulations – Detailed and Explained

Posted on December 13, 2010 by scarbsf1

Finally the FIA have published the detail of the 2011 technical regulations. There were no major surprises amongst the rules. There being rules to effectively ban: double diffusers, F-ducts & slotted rear wings. Newly introduced were the mandated weight distribution and adjustable rear wing.

There’s a lot to cover, so I wont cover every rule change and neither can I cover them in detail. but here’s the main points (with the rule in italics).

The full FIA regulations are detailed here: FIA F1 2011 Technical Regulations

Ban on connected shark fins

Another route to banning F-ducts, as well as a move to limit the ever expanding rear fin, the rule prevents any bodywork reaching the rear wing.

“3.9.1 No bodywork situated between 50mm and 330mm forward of the rear wheel centre line may be more than 730mm above the reference plane.”

Ban on slots in the beam wing

With the exception of the central 15cm, the beam wing cannot have a slot that widens internals to create a blown slot. Only Williams raced this last year, but the practice has prevented. This reinforces the fundamental rule that the lower wing should only be formed of one element

“3.10.1 Any bodywork more than 150mm behind the rear wheel centre line which is between 150mm and 730mm above the reference plane, and between 75mm and 355mm from the car centre line, must lie in an area when viewed from the side of the car that is situated between 150mm and 350mm behind the rear wheel centre line and between 300mm and 400mm above the reference plane. When viewed from the side of the car no longitudinal cross section may have more than one section in this area.
Furthermore, no part of this section in contact with the external air stream may have a local concave radius of curvature smaller than 100mm.
Once this section is defined, ‘gurney’ type trim tabs may be fitted to the trailing edge. When measured in any longitudinal cross section no dimension of any such trim tab may exceed 20mm.”

Ban on slots in the rear wing

As with the beam wing, the upper rear wing is prevented from having slots extending beyond the central 15cm. This prevent F-ducts or other blown slots, the latter which have been exploited for several years.

“3.10.2 Other than the bodywork defined in Article 3.10.9, any bodywork behind a point lying 50mm forward of the rear wheel centre line which is more than 730mm above the reference plane, and less than 355mm from the car centre line, must lie in an area when viewed from the side of the car that is situated between the rear wheel centre line and a point 350mm behind it.
With the exception of minimal parts solely associated with adjustment of the section in accordance with
Article 3.18 :
- when viewed from the side of the car, no longitudinal cross section may have more than two sections in this area, each of which must be closed.
- no part of these longitudinal cross sections in contact with the external air stream may have a local concave radius of curvature smaller than 100mm.
Once the rearmost and uppermost section is defined, ‘gurney’ type trim tabs may be fitted to the trailing edge. When measured in any longitudinal cross section no dimension of any such trim tab may exceed 20mm.
The chord of the rearmost and uppermost closed section must always be smaller than the chord of the lowermost section at the same lateral station.”

Limit on Rear wing support pylons

The number, thickness and cross-section of the rear wing support pylons are now more tightly controlled.

“3.10.9 Any horizontal section between 600mm and 730mm above the reference plane, taken through bodywork located rearward of a point lying 50mm forward of the rear wheel centre line and less than 75mm from the car centre line,
may contain no more than two closed symmetrical sections with a maximum total area of 5000mm2. The thickness of each section may not exceed 25mm when measured perpendicular to the car centre line.
Once fully defined, the section at 725mm above the reference plane may be extruded upwards to join the sections defined in Article 3.10.2. A fillet radius no greater than 10mm may be used where these sections join.”

Clarification of the starter motor hole

After some teams were exploiting oversized starter motor holes in the diffuser to create a slotted effect, the FIA clamped down with a clarification. This has now been written into the rule book.

“3.12.7 No bodywork which is visible from beneath the car and which lies between the rear wheel centre line and a point 350mm rearward of it may be more than 125mm above the reference plane. With the exception of the aperture described below, any intersection of the surfaces in this area with a lateral or longitudinal vertical plane should form one continuous line which is visible from beneath the car.
An aperture for the purpose of allowing access for the device referred to in Article 5.16 is permitted in this surface. However, no such aperture may have an area greater than 3500mm2 when projected onto the surface itself and no point on the aperture may be more than 100mm from any other point on the aperture.”

Ban on Double Diffusers (DDD) and Open Exhaust Blown Diffusers (EBD)

Due to a previous weakness in the rules defining the underfloor, teams were able to exploit this to create the double diffuser. Double diffusers were only possible as an opening could be created in the gap been the reference plane, step plane and the diffuser. Now the rules close this avenue off.
Additionally this opening allowed teams to open up the front of the diffuser to blow the exhaust through for an even greater blown diffuser effect. This rule also prevents this opening in all but the outer 50mm of the split between the diffuser and the floor.
One additional clarification is that the suspension must not form any of the measured point for the under floor. Previously the minimum height was exploited by some teams placing wishbones or Toe-Control arms across the top an opening in the diffuser.

“3.12.9 In an area lying 450mm or less from the car centre line, and from 450mm forward of the rear face of the cockpit entry template to 350mm rearward of the rear wheel centre line, any intersection of any bodywork visible from beneath the car with a lateral or longitudinal vertical plane should form one continuous line which is visible from beneath the car. When assessing the compliance of bodywork surfaces in this area the aperture referred to in Article 3.12.7 need not be considered.

3.12.10 In an area lying 650mm or less from the car centre line, and from 450mm forward of the rear face of the
cockpit entry template to 350mm forward of the rear wheel centre line, any intersection of any bodywork
visible from beneath the car with a lateral or longitudinal vertical plane should form one continuous line
which is visible from beneath the car.
3.12.11 Compliance with Article 3.12 must be demonstrated with the panels referred to in Articles 15.4.7 and
15.4.8 and all unsprung parts of the car removed.”

Driver operated F-duct

Even though the loop holes in the rear wing regulations have been closed, this additional new regulation prevents the driver influencing aerodynamics. So that other driver controlled F-duct type devices cannot be exploited other areas, such as: front wings, sidepods or diffuser.

“3.15 With the exception of the parts necessary for the adjustment described in Article 3.18, any car system, device or procedure which uses, or is suspected of using, driver movement as a means of altering the aerodynamic characteristics of the car is prohibited.”

Ban on movable splitters

As with some other rules, this is a 2010 clarification now added to the regulations. Its thought that teams were allowing their splitter to flex upwards, to allow the car to run a more raked attitude and lower front wing ride height. There are now more stringent tests and restrictions on the splitter support mechanisms.

“3.17.5 Bodywork may deflect no more than 5mm vertically when a 2000N load is applied vertically to it at three different points which lie on the car centre line and 100mm either side of it. Each of these loads will be applied in an upward direction at a point 380mm rearward of the front wheel centre line using a 50mm diameter ram in the two outer locations and a 70mm diameter ram on the car centre line. Stays or
structures between the front of the bodywork lying on the reference plane and the survival cell may be present for this test, provided they are completely rigid and have no system or mechanism which allows non-linear deflection during any part of the test.
Furthermore, the bodywork being tested in this area may not include any component which is capable of allowing more than the permitted amount of deflection under the test load (including any linear deflection above the test load), such components could include, but are not limited to :
a) Joints, bearings pivots or any other form of articulation.
b) Dampers, hydraulics or any form of time dependent component or structure.
c) Buckling members or any component or design which may have, or is suspected of having, any non-linear characteristics.
d) Any parts which may systematically or routinely exhibit permanent deformation.”

Driver adjustable rear wing

The driver adjustable front wing is now deleted from the rules and instead the rear wing is now driver adjustable. This is because the expected benefit of greater front wing angle never provided the driver with more grip when following another car. The front flap adjustment was much more a solution to tune the cars handling in between pitstops. The TWG found that the loss of drag from the rear wing was a more effective solution to allow the following to overtake. Now the rear wing flap can pivot near its rear most point and open the slot gap from 10-15mm to up to 50mm. Opening this gap unloads the flap and reduced both downforce and drag.
This being controlled by the timing gap to the car ahead and managed by the FIA. So there’s two ways the driver can use the system. Firstly in free practice and qualifying the rear wing is solely at the control of the driver. They can adjust the wing at any point on the track and any number of times per lap. So for the ideal lap time, as soon as the car is no longer downforce dependant (straights and fast curves) the driver can operate the wing, just as they did with the F-duct. Although a small complication to the driving process, at least their hands remain on the wheel and not on a duct to the side of the cockpit.
Then in the race the wing cannot be adjusted for two laps, then race control will send signals to the driver via the steering wheel, such that when they’re 1s or less behind another car at a designated point on the circuit, the rear wing can be trimmed out. The wing returns to the original setting as soon as the brakes are touched.

“Furthermore, the distance between adjacent sections at any longitudinal plane must lie between 10mm and 15mm at their closest position, except, in accordance with Article 3.18, when this distance must lie between 10mm and 50mm.”

3.18.1 The incidence of the rearmost and uppermost closed section described in Article 3.10.2 may be varied whilst the car is in motion provided :
- It comprises only one component that must be symmetrically arranged about the car centre line with a minimum width of 708mm.
- With the exception of minimal parts solely associated with adjustment of the section, no parts of the section in contact with the external airstream may be located any more than 355mm from of the car centre line.
- With the exception of any minimal parts solely associated with adjustment of the rearmost and uppermost section, two closed sections are used in the area described in Article 3.10.2.
- Any such variation of incidence maintains compliance with all of the bodywork regulations.
- When viewed from the side of the car at any longitudinal vertical cross section, the physical point of rotation of the rearmost and uppermost closed section must be fixed and located no more than 20mm below the upper extremity and no more than 20mm forward of the rear extremity of the area described in Article 3.10.2 at all times.
- The design is such that failure of the system will result in the uppermost closed section returning to the normal high incidence position.
- Any alteration of the incidence of the uppermost closed section may only be commanded by direct driver input and controlled using the control electronics specified in Article 8.2.
3.18.2 The adjustable bodywork may be activated by the driver at any time prior to the start of the race and, for the sole purpose of improving overtaking opportunities during the race, after the driver has completed a minimum of two laps after the race start or following a safety car period.
The driver may only activate the adjustable bodywork in the race when he has been notified via the control electronics (see Article 8.2) that it is enabled. It will only be enabled if the driver is less than one second behind another at any of the pre-determined positions around each circuit. The system will be disabled by the control electronics the first time the driver uses the brakes after he has activated the system.
The FIA may, after consulting all competitors, adjust the above time proximity in order to ensure the stated purpose of the adjustable bodywork is met.”

Mandated weight distribution

Along with the supply of Pirelli control tyres they will be matched to a mandatory weight distribution. Now the cars minimum weight is 640Kg, the specified minimum axle weights, equate to a weight distribution ranging between 45.5-46.7% on the front axle. This is a few percent behind the typical 2010 loadings.

“4.2 Weight distribution :
For 2011 only, the weight applied on the front and rear wheels must not be less than 291kg and 342kg respectively at all times during the qualifying practice session.
If, when required for checking, a car is not already fitted with dry-weather tyres, it will be weighed on a set of dry-weather tyres selected by the FIA technical delegate.”

Double wheel tethers

For safety a doubling of the wheel tethers has been regulated. Each tether needs to pass through a different suspension member and have its own mounting points on the upright and the chassis. There’s not expected to be any performance impact with this. But the tethers are somewhat heavier, so they and the side intrusion panel are part of the reason for the greater minimum weight limit.

“10.3.6 In order to help prevent a wheel becoming separated in the event of all suspension members connecting it to the car failing provision must be made to accommodate flexible tethers, each with a cross sectional area greater than 110mm². The sole purpose of the tethers is to prevent a wheel becoming separated from the car, they should perform no other function.
The tethers and their attachments must also be designed in order to help prevent a wheel making contact with the driver’s head during an accident.
Each wheel must be fitted with two tethers each of which exceed the requirements of 3.1.1 of Test Procedure 03/07.
Each tether must have its own separate attachments at both ends which :
- are able to withstand a tensile force of 70kN in any direction within a cone of 45° (included angle) measured from the load line of the relevant suspension member ;
- on the survival cell or gearbox are separated by at least 100mm measured between the centres of the two attachment points ;
- on each wheel/upright assembly are located on opposite sides of the vertical and horizontal wheel centre lines and are separated by at least 100mm measured between the centres of the two attachment points ;
- are able to accommodate tether end fittings with a minimum inside diameter of 15mm.
Furthermore, no suspension member may contain more than one tether.
Each tether must exceed 450mm in length and must utilise end fittings which result in a tether bend radius greater than 7.5mm.”

No more shaped wheel spokes

After the static front wheel fairings that abounded in 2009, were banned and the wheel design homologated, there must have been some surprise that Ferrari managed to create an aerodynamic wheel shape in 2010. This is partly limited now by the restriction on surface area for spokes and shaping. The limited only allows 13% of the wheel centre to be spoked, meaning that a ten spoke wheel has to have spokes just 16mm wide.

“12.4.6 When viewed perpendicular to the plane formed by the outer face of the wheel and between the diameters of 120mm and 270mm the wheel may have an area of no greater than 24,000mm2.”

Clarification of mirror positions

Again when the FIA clarify a rule or make a change for safety reasons, we don’t get to see the detail of this change until its put into the regulations. The removal of outboard mirrors was brought in early last year and now the mirrors can effectively be no more than 27.5cm from the cockpit opening

“14.3.3 All parts of the rear view mirrors, including their housings and mountings, must be situated between 250mm and 500mm from the car centre line and between 550mm and 750mm from the rear edge of the cockpit entry template.”

Ban on blade roll structures

Mercedes surprised many with their blade-like roll structure, reducing the obstruction to the rear wing and allowing for a much shorter inlet tract for the engine, the solution was likely to be copied. A minimum cross section forced teams to have a wider section above the drivers head, negating the fundamental benefit of the solution

“15.2.4 The principal roll structure must have a minimum enclosed structural cross section of 10000mm², in vertical projection, across a horizontal plane 50mm below its highest point. The area thus established must not exceed 200mm in length or width and may not be less than 10000mm2 below this point.”

Dash roll structure point maximum height

With the cockpit opening fixed at 550mm, teams have often raised the front of the chassis around the dash bulkhead to create a raised nose. In the first of several limits for both 2011 and 2013, with even more stringent plans for 2013, the height of the front of the chassis is now being controlled. The limit for this point is now 670mm, still some 120mm above the cockpit opening.

“15.2.3 The highest point of the second structure may not be more than 670mm above the reference plane and must pass a static load test details of which may be found in Article 17.3.”

Limit on front chassis height

As already explained teams raise the position of the front (AA) and dash (BB) bulkheads to create space under the nose for airflow to pass in between the front wheels and reach the rear of the car. The trend for “V” sections noses, introduced on the Red Bull RB5 in 2009, makes the front of the chassis even higher, often being visible above the height of the front tyres (~660mm). Now both these bulkheads need to be at 625mm, some 75mm above the cockpit opening.

“15.4.4 The maximum height of the survival cell between the lines A-A and B-B is 625mm above the reference plane.”

Limit on shaped Rear Impact Structures

Since the 2009 aero rules, teams have been shaping the rear impact structures into ever more curved shapes to lift it clear of the diffuser and pass it underneath the beam wing. The tail of this structure must be centred at 300mm high, to prevent extreme banana shaped structures, this rule forces the structure to vary by no more 275mm.

“Furthermore, when viewed from the side, the lowest and highest points of the impact absorbing structure between its rear face and 50mm aft of the rear wheel centre line may not be separated vertically by more than 275 mm.”

Audi R18 – Contemporary LMP Tech

Posted on December 11, 2010 by scarbsf1

Audi have just launched their latest LMP car to contest the Le Mans 24h, Now with a downsized V6 turbodiesel the chassis has been given a closed cockpit. The chassis exploits both current thinkign and some innovations. I’ll soon add more detail to this article, for now I just wanted to post the pictures, each with as simple summary

R18 - front diffuser

R18 - Diffuser flow out through gap between chassis and wheelpod

R18 Tail fin - working with the chamfered underfloor, the fin creates high pressure above the car to prevent blowovers when the car's sideways

R18 wing pillar, the pillar forms a structural end to the tail fin, it's swan-necked to fre the underside of the wing from obstructions

R18 two part doors - following Peugeots lead, the doors are split to meet the FIA template, only the top half is normally opened

R18 front vanes - in order to maintain flow 'through' the car and still obscure the mechanical parts, these vanes are used

R18 wheelpods - pressure build up in the wheel arches creates lift, venting the arch helps creates downforce, the size of the upper vented openings are constrained by the rules

Spring-Less Rear Suspension – A Quiet Revolution

Posted on December 3, 2010 by scarbsf1

In the latter part of the year suggestions were that teams were discarding the rear side springs to allow very soft rear ends. This has proved to be the case, in the past few years teams have been removing their rear torsion bars to gain greater control of suspension set up. This revolution has been quietly spreading as many teams have gone this route.

An early sign springs were being removed was the I-Racing game, which accurately modeled the FW31 with the Williams teams assistance, the game provided no scope for rear springs. Equally comments made by Anthony Davidson over the Abu Dhabi Grand Prix weekend suggested that McLaren’s extreme stiff frontsoft rear was due to this set up. Leading to Buttons problems locking up the inside wheel under braking. Closer investigation with technical people close to the sport prove this to be case and the practice is widespread amongst several teams, already McLaren and Williams are highlighted as adopting this practice, but Toyota and red bull are sporting this set up, by virtue of their gearbox supply this suggests that force India and Toro Rosso have the option too. Although this seems to be a relevantly recent practice as most teams first designed this into the 2009 cars, albeit it may have been tested or raced before then.

Suspension on F1 cars has the joint purpose to control the cars attitude both for aerodynamics and tyre dynamics. These often contradictory requirements have lead to compromises, largely against tyre performance and more to the benefit of aero control. Aerodynamicists want the car to run flat (or raked) with little change in roll or ride height. For mechanical grip the car needs softer attitude control. This has lead F1 cars to run quite stiff front ends and softer rear ends, both in roll and heave. A soft rear ARB creates more mechanical grip, which then in turns needs to be controlled by a stiff front anti roll bar. For aerodynamics reasons the front wing and splitter like to be flat to the track surface to gain most downforce, thus this also tends to require a stiff anti roll bar.
At the extreme end of this set up characteristic this has been exhibited most clearly in McLarens handling. The car gains traction from the soft rear anti roll bar, but the stiff front roll bar means that the rear heavy car tends to roll at the rear and this picks up the inside front wheel going into turns.
On a side point although McLaren run what has been called a stiff front axle, their apparent problem with grip over bumps going into turns is not necessarily a reflection of this set up, more that the cars aero requires tight ride height control, it is possible to run stiff anti roll bar and still have a compliance for coping with bumps.

Heave is when the car moves vertically, thus both wheels are rising or falling together
In a typical rear suspension the effect of heave is that the heave spring (blue) and each side spring (yellow) is providing stiffness. The dampers (Red) damp the motion.

Roll is when the car tilts, thus one wheel is rising and one is falling
In a typical rear suspension the effect of Roll is the ARB (orange) and the side springs provide the stiffness. Again, the Dampers (Red) damp the motion

Single wheel bump, which tends to be for riding kerbs or bumps in the track is a secondary requirement to heave and roll control, spring rates are not normally tuned for this requirement, instead the cars dampers allow freer suspension movement when the wheel suddenly rises up at a greater rate than normal, the damper has different rates for the wheel rising at different speeds, known as low speed (the cars chassis moving slowly i.e. pitch roll) high speed (bumps) and often a tertiary setting known as ‘blow off’ where the damper will provide a far lower damper rate for extreme wheel speeds such as kerbing.

Hence in both heave and roll the side springs are providing additional stiffness to the effective spring rate, thus both roll and have are coupled to the rate of the side springs. If we can do away with the side springs then both roll and have can be totally independent and controlled by their relevant springs. If you need a softer ARB rate, then the side springs are the limiting factor.

When you do away with the side springs, the heave and roll bar rates are higher in order to replace the spring rate added by the side spring. As long as each of these devices has a wide enough range of springs then there is no loss in control.

It’s noteworthy that both rear dampers are used, in the nineties we saw monoshock front ends, which utilised both a single spring and single dampers. But monoshocks only have one damper so the control of roll is undamped. With a side spring-less set up there’s two dampers, controlling roll motion. Which is an obvious improvement in vehicle control over Monoshocks.
Although there are some set backs with a side spring-less set up, some suspension designers want a non linear rate to the heave and wheel rates and sometimes different rising rate curve for each of these elements. This is achieved by the linkage (pushrod or pullrod) and the rocker geometry, going for side spring-less set up prevents having differing wheel and heave spring rising rates. In some engineers opinions, this is the removal of a needless layer of complexity.
A heave element not only supports the rear axle heave motion, but the element provides a non linear rate. Ground clearance is used up through downforce compressing the suspension as speed increases. The heave element has a range of free movement, this is taken up as ride height lowers until the then the heave spring itself (or Belleville stacks or bump rubbers) come into effect and add considerable rate to the heave motion. This prevents grounding or choking the underfloor through low ground clearance.
Equally making set up changes is both simplified and complicated. Engineers can now change either roll or heave rates independently, before changing a changing torsion bar effectively altered both. But changing a torsion bar, while not a quick task was the switch of an isolated component. Now teams will need to change the entire heave spring or ARB assembly.
An additional benefit is if a team wants to commit fully to the side spring-less set up, the packaging of the suspension becomes far easier, no longer having to package long torsion bars. This is perhaps a reason why Red Bull were able to effectively package the pullrod set up, as the pivot for the rocker is near vertical, fitting a torsion bar in this position would have been be tricky.

With the design of next years car leading towards a widespread adoption of pullrod, the option to adopt side spring-less will be attractive to aid packaging. Although the side spring-less pushrod set up will also allow dampers and rockers more freedom to be packaged at the front of the gearbox casing. Adoption at the front of the car is possible too, there is lesser need as the front roll rate is higher and the torsion bars can add to the effective rate. But simpler packaging and tuning may still be attractive for a designer.

Tyre Testing Sensors – What was seen in Abu Dhabi

Posted on December 2, 2010 by scarbsf1

The recent Young Driver and Tyre test in Abu Dhabi was a rare chance to see F1 cars in pure testing mode. Although team’s programmes varied, many teams used the test to gather ‘before and after’ data to see the effect of the change to Pirelli tyres. A change in supplier will have an impact not only on tyre usage, but also subtle change in tyre shape which will also affect aerodynamics. Hence we saw teams with a wide range of tyre temperature monitoring and air flow mapping sensors.
Since the introduction of the SECU teams have had to keep their telemetry system separate to the chassis engine management functions. For simplicity the race weekends tend to gather telemetry from the SECU and its homologated sensors. In testing the car is rigged up with dedicated data acquisition hardware and sensors. Some of these are complimentary to the normal range of sensors and are hardly seen, while some systems are fitted only for specific runs aimed at gathering a specific type of data from the car.

Tyre Temperature
Often run on race weekends, normally only for Friday practice, tyre temperature can be measured in several ways. Either by simple infrared sensors looking at specific band of the tyre, cameras monitoring the entire tread width and even wheel mounted sensors measuring the carcass temperature inside the tyre.

Simple Infra Red (IR) Sensors

Force India used simple IR sensors to measure a band of tyre temperature

The simplest sensors are IR sensors, they only look at one band around the tyre and hence they tend to look at the inside tread, due to the suspension camber loading this section of tyre most heavily. These sensors need to be in relatively close proximity to the tyre, and hence packaging can be an issue. They will map a single temperature over time.

On race weekends these can be seen on the floor in front of the rear tyre, a specially design niche in the floor allows a smooth cover to be fitted over the sensor and provide a route for cabling to enter the cars wiring loom around the gearbox engine interface. They are more difficult to package at the front, before the 2009 wide front wing rule the front wing endplate provided a useful location to mount a sensor, albeit one that only measured when the wheel was in the straight ahead position.

Before 2009 the endplate provide a home for a single 2D sensor

FIF1 used the usual floor mounted sensor, plus this endplate mounted one

In testing teams prefer to fit booms to the upright to have a single or array of sensors to steer with the wheel, thus getting data from around the whole lap rather than the few moments when the cars is in a straight line. Both Williams and Force India exploited these booms in the recent test. While red bull had a cable hanging from beneath the front wing, suggesting they had fitted an IR sensor there.

Without the wheel fitted you can see the array of three sensors

Williams used these booms in Abu Dhabi

IR Cameras

Force India also use IR cameras to measure the entire width of tyre temperature

A more recent development has been the adoption of IR cameras to monitor the entire width of the tread through out the lap. Pioneered by McLaren in 2003, using Thermoteknix hardware, the set up has since been adopted by most teams and teams outside of F1. The tiny camera is easy to package and have been used in heavy industry, they are rugged enough for F1 too. As the camera can be focused to look at the entire face of the tyre and from a distance, their positioning much easier. They no longer need to be mounted to the upright to steer with the wheel, as the camera will automatically pick up the edge of the tyre and read the temperature across the full profile. Although the camera sees the entire face of the tyre, it narrows down the data collected to just a strip across the tyre. The resulting data plotted as a graph of time versus position over time.

This provides freedom to mount the camera in one of many locations; they are often inside the mirror casing or in the sidepod fronts for the front tyre camera, while the rear tyres are easiest monitored form a pod mounted on the floor ahead of the rear tyre. Force India fitted their rear tyre camera on the roll hoop fitted inside a dummy FOM camera pod.

Virgin used tyre cameras mounted inside holes in the sidepod

Sauber used a grey 'camouflaged' IR Camera inside the pod wing

Tyre Carcass temperature sensor

Beru have this wheel mounted IR sensor system to measure temperature inside the tyre

Measuring the temperature of the surface of the tyre is one factor; the temperature of the core of the tyre is harder to measure. Simply measuring the temperature of the gas inflating the tyre is not accurate enough. Beru have developed a wheel mounted IR sensor for measuring the inside surface of the tyre.

Tyre shape
A tyres shape is not a simple cylinder, the tyre in fact has a complex shape, as the tyre deforms in both side and front elevation as it contacts the track. This shape changes with steering and speed/downforce. Mapping this complex dynamic shape is important as it will feed back to correlate to the shape seen on the rubber wind tunnels tyres provided by Pirelli and also modeled in CFD. The shape changes are subtle, but equally very different to the Bridgestone and the flow off the front wing and around the rear end will be heavily influenced.

Ferrari fitted a pod inside the diffuser view the tyre

Ferrari modeled the side profile of the tyre in detail using special pods, there were two pods fitted to the left hand of the car, one at the front and another at the rear. The front tyre pod fitted to the upright to turn with the wheel, while the rear pod was placed inside a cutaway section of the diffuser, the exhaust resited to blow away from the sensors. This would have impacted aero but the test results would still be representative enough for the team.

Williams used this 'Rake' an array of pressure taps to map the flow off the wheel

Williams and latterly McLaren also mapped the flow off the front tyre, to do this an array of pressure taps were fitted to a boom that could rise and lower to get a wider map of the flow. These would see how the tyre affected the flow off the front wing; tests were repeated with both tyres using a baseline set up on the car, so as not to confuse the results.

Tyre temperature article http://www.thermoteknix.com/content/english/misc/publications/press/documents/RACETECH.pdf

McLaren Electronic Systems (MES) – Sensors

As well as providing the SECU and other homologated electronics on the cars, MES also produce this range of Tyre temp sensors