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Showing posts with label Giorgio Piola. Show all posts
Showing posts with label Giorgio Piola. Show all posts
9 Oct 2012
Red Bull (Possibly McLaren) Rear Wing DDRS (Double DRS) RWDDRS

Firstly I'm going to start this post by trying to alleviate some confusion surrounding the terms  Double DRS, DDRS & DRD.

I think with the emergence of this new form of DDRS on the Red Bull it may be pertinent to re-phrase the original Mercedes DDRS as FW-DDRS (Front Wing Double DRS).  This is due to the fact that the secondary function (Double) within their system allows the Front Wing to shed downforce/drag when DRS is activated utilising pipework that runs the length of the car.

The systems being employed by Red Bull (and possibly McLaren) can then be RW-DDRS (Rear Wing Double DRS) as their secondary function is to further enhance the properties of the rear wing region.

Lastly we have DRD (Drag Reduction Device) this is the passive system that both Lotus and Mercedes have been working on over the last few races and is now being coined as such by the mainstream media after myself and Craig Scarborough lobbied them to: http://somersf1.blogspot.co.uk/2012/09/lotus-mercedes-drd-drag-reduction.html

RW-DDRS

Above: Image of the New Rear Wing Top Flap with a large end fence covering an aperture in the Endplate below:


Above: When DRS is active an aperture is revealed in the Endplate activating another area of bodywork via tubing in the thickened Endplate (In the latest image, which is the lower of the 2 it's clear that the duct is much smaller than originally thought so is more likely the fluid switch in a larger system)

Giorgio Piola's initial assessment of the Red Bull DDRS on F1.com is a little flimsy claiming when DRS is active the airflow is sent down through the endplates and exits in the central portion of the beam wing augmenting the diffuser flow. http://www.formula1.com/news/technical/2012/878/1012.html  Mark Hughes has now also added fuel to this in his article: http://www1.skysports.com/formula-1/news/22058/8151511/The-double-DRS-debate

It's worth pointing out at this stage that although the prime function that is mentioned here is drag reduction but intrinsically in these cases downforce is actually increased too.  This is done by blowing a specified area in combination with an increased AoA (Angle of Attack) of the bodywork in that region.  When the airflow is moved away (DRS activated) the AoA is too steep and the region stalls (downforce is reduced along with drag = Drag Reduction)


Several avenues of enquiry are available as possible reasons to use DRS as a secondary function including the one described by Giorgio and Mark above and illustrated here by Mario Keszeli

The problem I have with this however is that stalling a normal configuration beam wing won't release a huge chunk of drag. However if you were to run more AoA on the beam wing and blow it with air from the engine cover it would create more downforce. Activating DRS would draw the air usually dispensed in this area past and up the Rear Wing Endplates and out of the hole revealed by the top flap rotating reducing drag by stalling the Beam Wing.  

I'm unable to reconcile the above with the pictures available as no holes or slots are apparent in this region (at least in the images available)

If we are considering the Beam Wing as a plausible area to stall then we must also consider stalling the outer region of the Beam Wing (Near the endplates) as illustrated by Mario below:

In the pictures below we will see that at the moment there are no plausible area's that are being blown in order to create downforce and then reduce drag when DRS is activated:

In this last picture I've added lighting effects to this last picture in order to evaluate the underside of the beam wing for additional holes or slots none of which can be seen. (The small hole toward the edge of the beam wing / endplate has been included in the RB8 design process for some time)

Before we get to my idea's, an idea put forward by Petr Hlawiczka was that airflow is ejected laterally from the Endplate beside the Mainplane as he showed us in this picture and illustrated by Mario:
Having looked into this theory more closely it would appear that the appearance of holes next to the mainplane aren't consistent with the design. The paint is applied to an separator that divides the mainplane from the 15mm outer exclusion zone.  However what can't be seen from the angle above is a small hole behind the separator shown in the images below:



Lastly I have two idea's of my own both of which come from my own thoughts on how to use DDRS and my investigations into the possible application that McLaren have been using since Spa

I floated the idea after Spa of McLaren using a form of rear wing DDRS with their Top Flap having hollow sections allowing air to be re distributed when DRS is activated to uncover the holes in the endplates. At that point I had no further proof as to what McLaren were stalling/moving air to/away from in unison with DRS but it was also apparent there was a slot on the trailing edge of the top flap.

 


Blowing the trailing edge will speed up the flow on both the front and rear surfaces of the plane enabling them to run a higher AoA which in turn creates more downforce and a more efficient wing. You'll notice they have large gurney tabs on the Top Flap to accentuate the effect of the trailing edge blowing.

This is done using a hollow wing, if we look at the picture below it shows a cross section of how I propose the wing is made.


Working along a similar vein as the original F duct system this makes the Rear Wings top plane more efficient with airflow from the engine cover running internally through the Beam Wing and up the endplates to the hollowed top plane where the air is ejected. McLaren's trailing edge slot features a wider section at the tips of the plane which I believe blows more to further reduce wing tip vortices.


When DRS is activated the blown effect is simply ejected laterally from the Endplate joining the free stream that feeds between the gap opened by DRS.  It may also be possible to use dynamic stall within the wings design here in order to increase downforce momentarily before the vortex that's been shed reaches the trailing edge.  This would enable DRS to be opened momentarily in advance of it's usual operation window = more planted/stabilized car when DRS is activated and a quicker qualifying lap.

I have insufficient pictures of the RB8's Rear Wing from Singapore and Suzuka to see if they have a similar slot on the trailing edge of the Top Flap to ascertain if they are too running a similar design.

Lastly we all know that the manipulation of exhaust gasses is the best way to increase rear downforce and will contribute to much better rear tyre life/degradation and so using a system to control the exhaust plume would be hugely beneficial.  Once again I have looked through many pictures of both the MP4-27 since Spa and the RB8 since Singapore and can't find the definitive answer (But based on Piola & Hughes articles neither have they)

In this last and possibly the most intriguing idea I believe they could channel air from the Engine Cover through the Beam Wing across to the Endplate and blow the air out of the side/rear of the endplate.  The idea behind this is either to create an air dam forcing the exhaust plume to follow the contour of the coke bottle over the top of the diffuser.  Or use the Coanda effect to manipulate it's flow inbound. This will make the diffuser more efficient and bring rise to a style of EBD the teams lost under the 2012 design regulation changes.


Above: RB8 possible placement of rearward blowhole consistent with the team reducing the size of the endplate strakes when the new wing arrived in Singapore (This hole does seem to appear on other photo's too but it could also be a light reflection) The lower image is from Korea.



One things for sure the appearance of RW-DDRS on the RB8 has raised more questions than answers for me but I'm fascinated to see how the RW-DDRS uses both the additional downforce and drag reduction it has been designed for.  The question also remains with only 5 races left and the title about to go to the wire does anyone else have a RW-DDRS up their sleeve?

EDIT 17/10/12 - Today I have added a new article on Red Bull's DDRS: http://somersf1.blogspot.co.uk/2012/10/red-bull-rb8-rw-ddrs-plausible.html
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18 Sept 2012
Ferrari Third Pedal or Foot Operated DRS

AmuS and Giorgio Piola recently ran a piece on Ferrari using a third pedal in their cockpits in order to activate/deactivate DRS. Many of you may believe that a third pedal was outlawed when McLaren used such a technique in 1997 on their MP4-12. The FIA does not specifically state a third pedal is not allowed in the regulations however the component used by Ferrari is a button rather than a pedal.

So why a foot operated button instead of the usual steering wheel button? As always in F1 the reason is mainly found in an aerodynamic advantage although it's a handy operation for the left foot to do whilst not braking too.

Above: Illustration from Giorgio Piola on the drivers action whilst not braking

DRS deactivation is either completed by re pressing a button or when applying the brakes, with the Ferrari system when the driver lifts his foot from the DRS button to brake the Rear Wing Top Flap will start to return to it's normal position creating downforce. This time differential helps to smooth the transition period and re attach the airflow before the braking phase begins.

Above: Illustration of Giorgio Piola's showing the additional DRS pedal/button exposed as the driver enters the braking phase

As teams push to extract more and more performance from DRS they know they are working with finite limits that can affect the cars stability for the drivers in the braking phase. This is even more crucial this year as the teams have lost a chunk of downforce from the EBD ban and strive to extend the Pirelli tyre life.

James Allison of Lotus has already stated that they will run a new Rear Wing around the streets of Singapore and from his statement I would consider it a sign they too may run a similar system:

'The new rear wing operates at the same downforce level as our Monaco spec rear wing, but with a better DRS delta. This means that this wing has better DRS switching from its maximum drag to its reduced drag settings. We believe we’ve been able to produce a rear wing which is at the higher end of the downforce spectrum but still able to allow the lion’s share of the DRS potential which is more difficult to achieve at high downforce levels. It will be interesting to see how it works on track.'

Lotus (Lotus Renault GP) are no stranger to this sort of thing having already used a foot operated DRS button when Nick Heidfeld drove for the team in 2011
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