2 weeks after my initial post on the
topic and on the eve of the Indian GP, fellow Tech analyst Gary
Anderson weighed in on the topic
lending
credence to my original analysis. On the back of this it seems
the FIA were also keen to allay any fears that Red Bull may be
gaining an advantage from heating the Splitter. Michael Schmidt of
German publication AmuS reported
that
the FIA conducted their own test (in India), heating the front of
the Splitter to 300
o before performing their usual
deflection test on the scrutineering rig.
If you have read both mine and Gary's
pieces you'd likely have concluded that we both believed that Red
Bull were circumnavigating the deflection test by allowing the
Splitter to heat up on contact with the track, transferring the heat
to the stay and buckling it. This would effectively allow the Rake
of the car to be increased and invariably make gains in downforce
from the larger expansion area available at the Diffuser.
The FIA's test disproved this theory
but something about the whole situation continued to irk me and so
although I have a mounting pile of articles that I have to write, I
have spent days trawling through Sutton Images collection and
reviewing footage.
The thing that stood out to me the most
when reviewing pictures of the RB9 was that the metal stay that forms
the connection between the underside of the chassis and the splitter
appears to be buckled. As you will see from the pictures below, the
flexion shown in the Stay isn't consistent and appears to move when the car is in motion.
This of course still sent me off down
the wrong garden path being distracted by the heating of the Splitter
by the titanium skids underneath and once again raising the question
of whether heat played a role in the upward deflection of the
Splitter (by virtue of the stay being buckled under heat). At this
point I decided to take heat out of the equation (as the buckle
remained a component of the Stay's design even at rest) and look at
why the team might want the Splitter to move, then it dawned on me...
Mass Damping
But didn't the original Mass Dampers
get banned?
Yes they did, however the Mass Dampers
of 2005/06 consisted of a spring mounted within the nosecone that
utilised a weight floated within it (around 9kg's). The premise is
that as the tyre deforms under load (without a Mass Damper) you lose
both mechanical grip and downforce consistency. We have however all
seen the slow motion replays in the past that show the amount of
oscillation the tyres have as they ride kerbs, this oscillation has a
frequency and if you were able to determine this frequency you could
dampen it's effects.
The original Mass Damper's employed in 05/06 were rumored to give a lap
time advantage of around 3 tenths but 8 years on and re-designed who can
guess what it would be worth? (Last time around we were in the middle
of a tyre war with the Michelin runners gleaning a larger advantage than
their Bridgestone counterparts)
I therefore propose that in the case of Red
Bull the Stay acts like the spring in the Mass Damper whilst the
Splitter is the weight required to make the spring act. How about
the Splitter's deflection test? I hear you say. Well the stay in
itself is rigid and impervious to the 2000NM or 200KG's of force
placed upon it on the rig and must not deflect more than 5mm. What
you will see in the following video though is that the stay whilst in
motion however is resonating at a frequency that allows it to move
beyond that 5mm. (Be warned you may have to watch the video several times to see the Stay buckling, also pay close attention to the fact that the stay buckles even though the plank/splitter doesn't impact with the track. Moreover it seems to deflect in opposition to the tyre oscillation)
Matching the frequency of the tyres oscillation has
a 2 fold effect:
Tyres: As the car corners and exerts
load into the tyres they begin to slip, if you can delay this slip
then not only should you be able to extract more grip (by virtue of a
bigger contact patch) but you will also over a sustained period see
less degradation.
Downforce: The damping of the chassis
against the tyre deformation means that aerodynamically the car
becomes more consistent, this of course means not only are Red Bull
perhaps creating the most downforce on the grid, it isn't being
spoilt by the natural movement of the car.
The effects of resonance can be
widesweeping and suffice to say that doing what I believe Red Bull
have doing here would be beneficial in terms of both creating
downforce and reducing drag. Having concluded that the Splitter is
indeed in motion, albeit not being caused by the heat generated by
the titanium skids transferring their heat into the upper face of the
Splitter, we can now look at this with more certainty.
The FIA deflection test is conducted in
order to ascertain whether the Splitter moves upward as it hits the
ground. What of course isn't tested is how much it droops when the
stay resonates at the frequency of the tyres. The buckle that
resides in the stay when it's at rest allows the stay to deform at
resonance therefore moving not only vertically but perhaps also
horizontally pivoting in the opposing direction to the deforming
tyres.
Lets think of the movements of the car
as it enters a corner:
Braking: As the car decelerates the
tyres deform, with the sidewall of the tyre squishing outward at the
same time the stay would deform vertically, this also minimises the
Splitter's interaction with the ground (which due to Red Bull's Rake
angle it's already in close proximity) allowing a consistent level of
airflow to pass over and under the splitter an onward to both the
Diffuser and driving the airflow around the Sidepods.
Turn In: Working in opposition to the
tyres oscillation, the splitter and stay dampen the cars movements
causing less rolling resistance and therefore hysteresis. As we know
heat management of the Pirelli tyres is crucial in terms of
degradation and so less hysteresis equals better degradation. As the
tyres are having to perform less vertical work we can also assume
that a net grip gain and loss of tyre slip is leveraged too.
Apex Speed: Less resistance from the
tyre and chassis equates to a more stable car and results in the
driver being able to carry more speed through the corner.
Top Speed: With the car able to carry
much more speed throughout the cornering phase it's therefore
conducive to the car being able to attain a higher top speed. A
peculiarity in the case of Red Bull who in terms of setup always tend
to favour the generation of downforce. If you have been following my
work this season though you'll have undoubtedly noted how much Rear
Wing angle the team have shed since the middle of the season. This
is of course because downforce generated at the Rear Wing is 'dirty'
and invariably comes with a much larger drag penalty than the
downforce generated in the Diffuser. By reducing the wing angle and
changing the gear ratios the team have been able to become fast not
only in the corners but on the straights too.
So what was all that about with the
Splitter heating up on the Thermal Imaging camera?
Red Bull as we know run an aggressive
amount of
Rake
which means occasionally under braking etc the Splitter and the plank
housed within it could contact the ground. If this were to occur
over a sustained period it would mean the car would fail the post
scrutineering check which allows 1mm of the plank to be worn away. The titanium skids are placed under the plank to stop this wearing from happening and in the case of Red Bull it appears the heat is then transferred into the upper surface of the Splitter and dissipated, like a heatsink. This is why we see the team putting drill marks in the upper surface too as it helps to increase the surface area and promote the direction in which they want the heat to dissipate.
If we were to look back at the history
of the original Mass Damper's in F1 we would of course know that
Renault pioneered the device that was subsequently copied by others
before the FIA banned it. It's a name though that we really should
turn our attention to; Rob Marshall, Red Bull's Chief Designer
pioneered the original Mass Damper when he worked at Renault. So
it's no wild stretch then for the team to take advantage on an area
of the car that worked so well in the past and redesign it for the
prevailing trend / regulations / technology available. If you'd like
to cast your mind back to this time last year I also posed the same
question on the
aeroelasticity
of Red Bull's nose in creating a similar effect. Rarely in F1
do we truly see an new innovation, the boundary pushing is usually a
team taking a pre existing idea and applying it a new way, this I
believe is another case of just that.
So if they are doing it, is it legal?
Well only Charlie Whiting and the boys
can truly determine that factor but as the Stay is allowable in the
technical regulations and only need pass the upward 200KG deflection
test on the rig I don't see why it wouldn't be. Although just like the original Mass Damper if it were to be found in use does it constitute a 'Moveable Aerodynamic Device'? Red Bull could argue just like Renault did that the device is moreover there to stabilise the car through harmonic matching.
Why hasn't X,Y,Z copied it?
Perhaps because they haven't noticed
it, someone has to start a revolution for there to be one in the
first place... (Renault started the last one, in terms of Mass
Dampers) or perhaps they have but just haven't implemented it to the
same level as Red Bull... Ferrari are their closest rivals who have a
chance to, as they too run the metal Stay. Mercedes don't utilise a
Stay, whilst Lotus use a Carbon Fibre one.
I'm
guessing Red Bull had the option to run this at the start of the
season, then swiftly found that the tyre construction wasn't
conducive to it's application or didn't yield as large a result as on
the 2012 construction tyres. As we can see below Red Bull actually
utilised a different stay prior to the change of construction mid
season.
Above: This is an image from Montreal
so before the change of construction, we can see here that Red Bull
are using a much thinner stay, plausibly to glean the same effect as there is a small buckle visible in the stay. However take a look at how the car is riding the kerb and it's more likely the stay has done so purely under load.
Above: Furthermore it's clear from this
image that during Free Practice (Montreal) the team had a rig in
place of the Stay. I'd suggest from the picture that this is an
actuator capable of moving the splitter to assess any issues that
could be created by using a harmonic stay.
As always I have tried to be as
expansive as I can with the resources available to me. Perhaps if I
had access to some of the footage used by the likes of the BBC/Sky I
could make an even more compelling case. I await your call guys.... and as always I invite your comments.
EDIT 08/11/13 - 16.37pm
After the piece being live for several hours now I have the following bits to add that may also aid in any questions:
Above: As we can see during the build process the team are performing their own checks on the deflection of the Splitter, note the stay is buckled which would give it the freedom of movement I've talked about above
Above: As shown in the .GIF above the stay broke on Vettel's car in Hungary, as pointed out by @Germyl barring Hungary Vettel has won 8 of the last 9 races, a coincidence?
EDIT: 09/11/13 10.00am
Those who have asked me why Red Bull would entertain doing such a thing when teams already utilise a legal form of this in the case of J-Dampers/Inerters:
You would be quite correct in your assessment that teams have since the banning of Mass Dampers utilized a legal version which allows Mass Damping in the form of J-Dampers/Inerters. On this basis I'd conclude that although these do a job of damping the deflection/oscillation of the tyres, can it be improved? We have all seen from slow motion replays of cars riding the kerbs just how much deflection/oscillation the tyre under goes. Perhaps Red Bull felt they could make gains with additional damping and thus this method was born.
EDIT: 09/11/13 17.44PM
After further analysis of the footage from Hungary both drivers (Seb & Mark) had broken stays at that GP for the race. Mark's stay actually broke much earlier in the race resulting in the upper surface of the Splitter dissipating most of the black paint by the end of the race, through heat being transferred from the skids below. Perhaps this is what led to the FIA placing the thermal camera on the RB9 in subsequent races....
(I have also checked the post race
technical report of which post race checks were only made to cars 5 and 16 which include the Skid Block thickness. This means even with broken Stays and more than likely at least in the case of Webber beyond the 1mm wear rate the cars were deemed legal)
Above: Mark Webber pits in Hungary and as we can see the stay has folded forwards, through constant contact with the track surface a big surface area of black paint is also missing from the top of the metal Splitter
EDIT 10/11/13
Additional photo's based on the comments below:
Above: Seb's car on lap 54 we can see the stay is detached and folding backward from the chassis mount
Above: Lap 56 and the stay is clearly detached on Seb's car
EDIT 18/11/13
During Mark Webber's pitstop at the Circuit of America's I noted that the Stay showed the pre buckle from the onboard footage as the car was dropped off the jacks the stay flexed/deformed further
Mark Webber's pit stop in full, including some scenes showing the wheels that are and aren't painted with Polysil
Edit 27/11/13
Splitter Stay watch in Brazil turned up a little more video footage where we see at the end of the images below the stay is at full length and diagonally reaching to the front left of the car. We must remember that the car was setup with wet weather in mind for Interlagos too and so perhaps the team had to make amendments to length and droop of the stay (Inters have a 10mm additional radius than the dry tyre, raising the ride height)
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Sunday, December 08, 2013
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Click the image for full size which makes it great for printing off.....
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