Update on how it links to the front wing
I’ve heard a lot of reporting about the Mercedes F-Duct stalling the rear wing and the likelihood of other teams already having a similar system.
I can see the logic in why people think that the DRS controlled duct blows the rear wing elements in a bid to reduce drag. I haven’t seen any evidence of this being the case; equally I can see several issues with this theory. The problem with the theories on the DRS duct stalling the rear wing are twofold; firstly the DRS is already cutting immensely, secondly the rules greatly restrict the ability to stall the rear wing. Back in to 2010 teams were using blown slots across the full width of the rear wing, these being used with perpendicular blowing to stall the wing or tangential blowing to act as an additional slot gap for more downforce. The rules introduced in 2011 aimed to prevent both of these types of slot.
To stall either the top rear wing or the beam (lower) rear wing, you need to blow a slot. In the post 2010 rules, slots are banned in any section of the rear wing (via a 100mm minimum radius rule); this ban applies to all three wing elements aside from the middle 15cm. So to use the DRS duct to blow a rear wing slot, all you’ll stall is the very centre section of wing. This area creates very little induced drag (most of that’s created at the wing tips), so stalling it will not improve top speed by much. Thus it will provide very little benefit.
It’s possible the DRS Duct could stall the flow around the sidepod, exhaust or diffuser. I’ve got no information on this, or a valid reason how this would benefit the aero. In my opinion the blowing to stall the front wing is still the most valid theory. Pictures have merged today of Schumachers car lifted on a crane that shows the slot sunder the front wing. other pictures also show close ups of the rear of the car, do not show any slots in the top or beam wings.
Search on sutton images for pictures d12aus3468.jpg, d12aus3467.jpg, d12aus3465.jpg
I suspect the two ducts leading from the beam wing into the engine cover are part of the system. Either taking the DRS-duct flow to the front wing directly, or by using the DRS-duct to switch the F-Duct. I can;t find where the F-duct switch is sited, perhaps inside the rear wing, in which case the two beam wing ducts might be of different uses, one feeding high pressure airflow to the F-Duct and the other feeding the flow to the front wing. As this is an evolving theory, I’ll post more on this system as we start to understand it better.
I’ve looked at the McLaren, Red Bull and Ferrari rear wings, as yet I can see no shaping to suggest a DRS-Duct is packaged inside the endplates. There’s little doubt these teams must be working on similar solutions. Although Red Bull and Lotus may probably not be developing this solution, as they are now querying the FIA on its legality LINK
We have now acceptance by the FIA that the DRS duct is legal, that Mercedes are running this system and pictures show the duct emerging from the beam wing reaching forwards inside the engine cover. Presumably, to reach towards the front-end of the car. No doubt more information will soon emerge on these systems.
other links:
DRS open showing the duct open beneath the flap (via AMus)
Rear wing no sign of any slots in the middle 15cm
Scarbsf1's Blog 
Craig, here’s another theory:
The two ducts are not running up the airbox, but down. They take air from the airbox and lead it to the beam wing mount. There’s a airflow switch, just like the F-duct airflow switch which used to sit in the airbox fins back in 2010.
The air from the small holes behind the rear wing’s upper flap actually only trigger this airflow switch. If disabled, the air just emerges somewhere to the diffusor or the starter hole. But if the DRS is active, the airswitch directs the air to another duct to the frontwing.
Just my 2 cents…
Wouldn’t the presence of a switch contradict Charlie Whitiing’s remark that the entire system is passive?
No. The switch is not an active element, but just a kind of specially crafted pipework. You can see an example of such switch in this picture of the 2010 F duct http://motorsport.nextgen-auto.com/gallery/pictures/2010/f1/gp-singapore-23sep/258wri.jpg
Main air feed comes from the airbox, and at the furcation it normally takes the the way to a neutral outlet (the big diagonal pipe). The air switch is triggered by a small pipe coming from below. If it feeds some air to the switch, the main flow is slightly “pushed” and redirected into the upper pipe which, in case of the 2010 F duct, leads to the rear wing. This is entirely passive aerodynamic.
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Couldn’t they blow the beam wing? Using the ducts above the gearbox to supply the air and the DRS opening as the switch.
You really think they will duct air from the back of the rear wing, through the whole car, to the front wing?
I’v been following Autosport’s coverage of this saga and much to my amusement they’re adamant that it’s an F-duct for the rear-wing! Craig I’m with you, I see no benefit given the DRS, addressing aero balance is the only logical conclusion – given Ross Brawn’s quotes I think that he’s quite amused that people are thinking rear-wing blowing too.
Is it possible they are just blowing the diffuser itself? This might return the downforce lost by the DRS of the rear wing (without the drag)keeping the car balanced while still using the speed activated stalling front wing they tried last year.
Watching Friday’s practice, although times were irrelevant, I had that feeling that Mercedes GP is quite there, behind the McLarens and maybe RedBull. I believe that the DRS does blow the rear wing because their speeds were faster than the rest. But I bet there is a trick on it and also works without activating the DRS. Defenitely the wing does help them and makes Aware of Schumacher’s talent, I think that Mercedes cut the gap between the top teams; I wouldn’t be surprised to see this team winning a couple of Grand Prix, and why not, fight for the driver’s title.
[Edit]
Defenitely the wing does help them and makes the car loose drag. Aware of Schumacher’s talent, I think that Mercedes has cut the gap between the top teams; I wouldn’t be surprised to see this team winning a couple of Grand Prix, and why not, fight for the driver’s title.
Blowing a DRS activated rear wing in order to stall it would be a waste of time, if the system does effect top-speed it would most likely be from shedding downforce/drag from the front wing.
Suggested primary function: correct the car’s aero balance with DRS enabled.
Possible (bonus) side-effect: less drag resulting in higher top-speed.
That’s merely what makes sense to me and most innovations in F1 do follow straight logic!
Yeah I’ve read in some websites that it apparently blows the front wing; so it’s from the rear to the front…I just wonder how does the airflow travel from rear to front in order to reduce drag. I’d love to see a diagram of how this works.
Most commentators (Sky, anyways) appear to believe the duct system adds more top speed. Given the way Rosberg and Schuey were flapping open everywhere I’m much more inclined to believe its a downforce balancer, ie probably linked to the front, designed to give Q3 performance. Merc proved last year they had top speed to spare.
These go hand in hand, The reduction of downforce on the front wing will generally result in increased speed as the drag will also be reduced.
Reblogged this on pptf1car and commented:
I agree with Scarbs here, there is no reason why they would blow the rear wing. Looks like the official F1 website got their technical analysis wrong concerning this ‘F-duct’
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It does mean they can use more wing angle so that when DRS is in use they gain the net same amount back. I’m still not convinced the two systems are linked but as Craig will tell you I made reference to blown rear wing endplates to him sometime last week (albeit I thought that perhaps the louvres were being blown at the time)
From this picture of the wing you can see a channel that runs down the outside edge of the main planes and meets with the endplates if I’m right this effectively makes the endplates acts like part of the RW’s main planes (an extension of them as such)
When the wing is in it’s closed position it acts as any other except it has a pinch point between the planes which will create a high pressure area = more downforce. When the DRS is activated the slot becomes apparent and air rushes into this low pressure area (hollow wing) making it high pressure rapidly creating the opposite effect on the outside of the wing cutting drag (This is why I think they are perhaps adding a bit more wing angle than normal)
Further to this the same could be going on further down at the beam wing?
I’m ready to be shot down in flames as it’s just a theory but thought i’d put it out there…
I haven’t a clue what they’re doing (hope Scarbs is proved right though) but one thing I think they cant be doing is using a blown front wing to actively manage ride height – they simply wouldn’t be able to use the system actively enough in the race, given DRS is limited. Surely they could only use a blown front wing passively at all times once the car reaches a given speed – ie, no need to link the DRS with the FW?
How about this: it’s a diversion by Mercedes, to make others scratch their heads and waste time and money on useless contraption ? 🙂
I think they are blowing their tires…
Lol
If it’s only active while the DRS is on then it was can’t be a very big advantage outside of qualifying. If it’s blowing the rear wing, there’s very little advantage to be had in the race because you can’t just add on extra downforce a-la-2010 fduct because you can’t use it all the way around the track. The only useful purpose of this rear wing if it’s blowing itself of the lower plane is that it allows you to run a race trim closer to a wet set up for downforce without compromising a dry qualifying session as much.
Basically if we see a strong wet performance having had a dry from Mercedes it’s more likely to be the rear wing. I highly doubt that’s what’s going on though.
Have you ever thought about that it’s not an inlet but an outlet? And that they do not use the air from the inlet to stall when the DRS is open, but the air from somewhere else to accelerate something as long as the DRS is closed?
How are the regulations for the beam wing? Theory: They take air from the airbox down to the beamwing, where it escapes a flat slot not to stall but to accelerate airflow during normal race conditions. With DRS is open, the air escapes through the hole in the endplates instead of the slot which reduces drag on the beamwing…
If FIA allows it they seem to have opened a can of worms.
If this is not driver activated due to the second hand nature of driver just using DRS then any
other driver activated toy that reshapes aero should be allowed.
I hit the brakes. Of course I am breaking but also a small hole in uncovered somewhere doing something clever.
I change the diff and then miracoulously something else happens.
If FIA allows it I think they put themselves in a very hard place.
What will they allow and what will they ban and how will the team know the difference without
tipping them off in advance. IF they allow this they have to allow anything else but they cannot do that so FIA have once more put themself in the limelight of the championship.
I can think of a plethora of solutions that can give small advances in many areas.
Smart by Mercedes. Creative solution and good engineering.
Now it is up to FIA, how they will handle it, can they handle it?
Yes absolutely, another short-sighted decision from the FIA. Just like when they decided to allow teams to design flexible aero parts.
The “secondary action” concept that they seem to be accepting here is ripe for abuse. How long before we see something activated by some “secondary effect” of the drink bottle pump – every time the driver takes a drink the car gains 5kph top speed.
I think the drinks companies would like that one… 🙂
I have a question. Why do we think that there must be only one. They could be having 2 or maybe even 3 f-ducts. One for the front wing one for the top of the rear wing and one for the bottom. OK I agree that top that already have DRS isn’t likely but since you are limited to the size of a moving part of DRS still possible since you can make bigger unmovable part.
What if those holes just go around the main wing and exit out right behind the main wing (i.e. those holes create an opening between the wing and the endplate)? The effect might be small but it would be much simpler than some of the other proposals. I haven’t seen any great shots of the back of the wing with the DRS open so this might be way off (and one of the pics above looks like there are no space for holes beside the main plane, but it could just be the photo or I could be way, way off). Just thought I’d throw out a simple idea.
Another idea. There are 2 pipes. And they are going in a general direction of exhaust. Could they be doing something with it. Is there a benefit if they blow it so it is not attached to the bodywork at speed when DRS is opened?
Since there are 2 pipes I think that we are talking about 2 f-ducts or they are stalling something near the back. I just can see a benefit of having 2 pipes if they are not necessarily. One would be lighter and wouldn’t take as much space. It wouldn’t be symmetrical but I don’t think that would be a problem. Unless 2 devices are necessary to feed front wing. But why… Diffident conditions on left and right side of the wing? This would cause diffident amount of air being blown out on each side and 2 devices would balance that but I see little benefit from that. Unless this is for hi speed DRS corners where you also get different conditions on rear wing from side to side… It might reduce effect on inner side of the car. Do to the drag this would also help turn the car the same way as McLaren 2nd brake pedal did in 1998.
The original F duct in 2010 also had these pipes. Search Scarbs blog for an image of the Force India 2010 system: An inlet on top of the airbox, then the airflow switch which directs the airflow either in a neutral duct or to the rear wing. The neutral duct ran under the airbox cover, splitted in 2 pipes and was blew its air somewhere on the diffusor deck left and right of the gearbox. As a conclusion, you can not gather 2 f-ducts from seeing 2 pipes…
I can’t see 2 pipes on Force India. Maybe I’m looking at the wrong image… But anyway thous are control pipes not bypass pipes as you say in Force India case. Unless you are saying that they are feeding pipes for rear wing stalling. But in any case they do separate into a V shape. So they probably aren’t feeding pipes. Feeding is done from nosecone if it is for front wing and thous are for control only. Unless they are doing something else.
@lucko
Sorry, I wasn’t precise enough and thought it’s easier to find what I’m talking about here in the blog. The 2010 Force India system is depicted here:
Craig seems to have bought it after season for his studies as seen here mounted on a SEAT http://yfrog.com/odg0hozj where you can see the 2 neutral ducts running down from the airbox. The control pipe comes from below and pushes the airflow to the upper pipe.
Yes I was looking at that exact picture. But It looked to me like only one square. But anyway it doesn’t separate into V shape as in Mercedes and it is not for control but for bypass. In far as I can figure out FI had a reason to do so. They needed to get air around mounting point for rear wing. As far as I remember McLaren was feeded to gearbox oil radiator so it was separated into even more “pipes”. So I really don’t see the relevance since thous are technical reasons…
I also read BBC explanation. And I don’t agree. They are saying that the air is being sucked from last wing to the front. I don’t agree. Turning the air around at 350kmh create a lot of drag. Feeding must happen from the front hole in the nose and the hols in back wing are only the control. Airflow switch is in my opinion in the front wing and if this is not a passive system it is only controlled from DRS. I think we have 2 control pipes. So we probably 2 airflow switches. Or they might even be a blowing pipes… Is there any advantage of blowing on the top of the rear wing when DRS is opened? I guess not… But one could be control for front wing and the other for supplying air for blowing below lower back wing and when it is not blowing it the bypass air blows to “double defuser” below rear crash structure.
Scarbs could they be using it for KERS cooling as well?- Kill 2 birds with 1 stone and use it as an excuse should it come under scrutiny!
The FIA will only tolerate these DRS-ducts as long as it gives Mercedes a sizeable advantage. As soon as all the big teams cotton on to it and the midfield teams are deep in the shit having spent much money on it without perfecting it, the FIA will ban it. Shame.
Aa you stated in the original article Lotus system was banned due to
brake torque altering ride height on the Lotus Reactive Ride Height system.
In each case the first element was legal as its primary purpose was as stated, but a secondary purpose was able to be exploited.
Then you claim that the blowing is not primarily to gain in top speed but to get aero balance in corners when using DRS. And that aero balance is really a way for aero to be used as a reactive ride height system to get aero balance in the car. The same as Lotus wanted with their system.
Even if the blowing is ok is the secondary or actually the primary reason not illegal? Since it is driver activated.
Maybe that is why Lotus is pissed and none of the others. They had a system like that and it got banned and now Mercedes have one but it is deemed legal since they claim the only use is high speed. If it was only high speed it would always be active like last year but they would loose out in corners, now they gain top speed and get aero balance in corners.
My take is that the Lotus system altered the ride height (or modified the ride height…i.e. to stop nose dive under braking) thus the suspension/car is then considered a movable areo device or active suspension. Those are seen as a much bigger issue then a passive device that makes a more effective DRS (which, IMO is a ridiculous device to begin with).
That’s my take on it.
Could the system even be used as getting maximum downforce when braking in high speed to slow corners?
It reacts first in the back of the car then the front hense it will bog down during breaking with the front wing as close as possible to the ground and gaining downforce thanks to suction etc. Schumachers wings hit the ground over and over when braking for first corner but none of the others did. He did go over the curb but if it was the best line the others would too.
It seems hard to fine tune though.
Scarbs, this is fantastic! Thank you. As Ross Brawn himself said, this is the reason we follow F1!
The depth of analysis, the way you re-engineer the point of discussion is truly fascinating. I’m looking forward to more analysis as the season progresses.
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I have to say, I don’t understand this at all – “And that aero balance is really a way for aero to be used as a reactive ride height system to get aero balance in the car.”
With today photos and the photo in Aus with the underside of Mercedes front wing i think the picture is clear.
With DRS closed – the system feeds the underside of front wing (maybee of the beam-wing too) maximizing the downforce by skin-effect (Coanda one more time). https://twitter.com/#!/gtmanpt/status/183249272538546176/photo/1.
With DRS open – The movemente of the upper flap discloses the sideplate hole depressurizing the system. The front wing (and the beam wing maybee) loses downforce and drag, the upper section of the rear wing is (more) stalled too by the increasing of air speed by the duct. https://twitter.com/#!/gtmanpt/status/183250602934009857/photo/1.
The draws is fast hand-made and the quality is not the better ….sorry…
Great post.
And:”I think they are blowing their tires…” lol 😉
ross brawn…